Original research Evaluation of a tool for rating popular diet books

Louise Williams and Peter Williams

Abstract (Nutr Diet 2003;60:185–97) Objective: The aim of this study was to develop a tool for use by nutrition professionals to evaluate popular diet books. Design: A questionnaire was developed incorporating quantified criteria based on current authoritative nutri- tion guidelines. It included 22 questions relating to nutritional adequacy, daily energy allowance, recommended rate of , flexibility and sustainability, physical activity advice, use of supplements, claims, authors’ credentials, and scientific evidence. The questionnaire was used to rate 35 diets in 20 popular diet books sold in Australia in 2001, and the practicality, validity and sensitivity of the tool were evaluated. A dietary analysis of three days of menus from each book was used to assess the validity of the questions assess- ing nutritional adequacy. Main outcome measures: Assessment scores for each book and correlation with dietary analyses. Statistical analysis: Spearman rank correlation was used to compare the nutritional adequacy of the diets assessed by the dietary assessment scores from the questionnaire and the numbers of nutrients likely to be pro- vided at < 70% RDI or < 100% RDI. One-way ANOVA was used to compare the mean scores of books written by those with nutrition qualifications, medical qualifications, and others. Results: The scoring of the questionnaire was found to correlate well with the nutrient analysis of the diets. Overall scores for the 20 books tested ranged from 32 to 97 out of a possible 100. Only five of the books were found to have scores over 80, the assessment criteria deemed compatible with current dietary and public health guidelines. Three diets provided less than 4200 kJ per day, while five books advertised weight loss results of greater than 1 kg per week and promoted or used ‘fast’ weight loss as a selling point. The majority of books relied on testimonials rather than supporting their results with data published in peer reviewed journals. Books by people with nutrition qualifications rated highest. Conclusion: The questionnaire provides a useful standardised tool for nutrition professionals to rank the nutri- tional adequacy of advice in popular diets books and to evaluate their approach to weight loss. Key words: weight loss, fad diets, obesity

Introduction provide nutritionally adequate advice and to provide sci- entifically accurate information. The incidence of obesity is increasing worldwide (1).In A large number of diet books are published each year, 1999–2000 the AusDiab study estimated that 60% of Aus- and books are identified by Australians as one of the most tralians aged 25 years or more were overweight or obese, useful sources of nutrition information (6).Someofthe with significant increases over the past 20 years (2). Popu- lation surveys in Australia suggest that 55 to 68% of adults have tried to lose weight at some time, 37 to 47% attempt weight loss annually, and that at any particular time 20 to 24% will be making an effort to lose weight (3). Australian Research Council Key Centre for Smart Foods, There is also evidence that many adolescents attempt to University of Wollongong, New South Wales lose weight by dieting. One study of Australian adoles- L. Williams, BA (Consumer Affairs) DipHumNutr, MSc(NutrDiet), cents found that 22% reported they were trying to lose Masters candidate weight (4). Dieting is particularly common among females P. Williams, BSc(Hons), DipNutrDiet, MHP, PhD, APD, Senior Lecturer Correspondence: P. Williams, Smart Foods Centre, Department of and books are one of the most popular sources of weight Biomedical Science, University of Wollongong NSW 2522. loss advice (5). The popularity of self-prescribed dieting Email: [email protected] means that it is important for weight loss diet books to

Nutrition & Dietetics (2003) 60:3 185 Evaluating popular diet books diet books are nutritionally sound, and offer advice on poses of this study only the weight loss aspects of the diets safe and effective weight loss, based on scientific evi- were considered in the evaluations. dence of efficacy and safety. Others, however, are questionable and may even be harmful to health. Some books contain a mixture of fact and fiction, while others Methods rely on a ‘special’ combination of pills or powders, or have complicated lists of rules and regulations that must Part1:Developingamethodtoassessthediets be followed. Food faddism refers to any dietary practice based on an exaggerated belief in the effects of nutrition A review of the literature was undertaken to identify on health and disease (7). There are a number of features methods that have been used by authors who have often found in popular weight loss books that have been attempted to evaluate popular diet books in the ascribed to fad diets in general (8). Simplistically they past (15–24,27). In addition, statements from the Dietitians may: Association of Australia (DAA) (28–30),theAmerican Dietetic Association (ADA) (31,32) and the National • promote or ban a certain food or food group; Health and Medical Research Council (NHMRC) (33,34) • imply that food can change body chemistry; were consulted. From these sources, the following com- • blame certain hormones for weight control; mon criteria were identified to consider when assessing • recommend supplements or health foods for every- fad diets: one; or • Nutritional adequacy • promise quick, dramatic or miraculous results. • Promised rate of weight loss The best way to lose weight and maintain weight loss • Energy content of the diet is simply to decrease energy intake and increase physical • Macronutrient composition of the diet activity (9). Analysis of data from the US National Weight Control Registry, which keeps a record of people who • Use of special supplements have been successful at maintaining weight loss, shows • Whether the diet can be followed comfortably on a that the people most likely to diet successfully are those long-term basis that followed a diet that restricted energy intake, con- • Physical activity recommendations tained less than 30% energy from fat, and included regular • Authors’ educational qualifications physical activity (10). Fad diets that promise novel dietary approaches for rapid weight loss rarely have any scientific • Scientific evidence. evidence to support long-term use (11). Quantitative targets were then established for each of However, the popularity of fad diets suggests that these factors, incorporating national nutrition guidelines many people appear to be more concerned with achieving where available, and these were used to develop a set of rapid weight loss than with the nutritional adequacy of the 22 questions to assess the content of popular diet books. diet or the likely maintenance of long-term weight The questionnaire is set out in full at the end. It was control (12). Rapid weight loss followed by rapid weight gain can have adverse effects on the metabolic rate, mak- designed to give each book a rating out of 100, divided into various sections as described below. ing it easier to gain weight in the future (13).Atleastone study has suggested that such variations in weight may constitute a health risk (14). In order to be able to respond 1. Nutritional adequacy appropriately to enquiries from the public, it is important This section is allotted 40 out of the total 100 marks. The for dietitians and other health professionals to be able to first five questions, about the number of serves recom- assess the reliability of popular diets and comment on mended per day from five food groups, are derived from them knowledgeably. recommendations in the Australian Guide to Healthy Eat- A number of reviews of popular diet books have been ing (AGHE) for men and women aged 19 to 60 years (35). carried out (15–23). The general consensus has been that, The next four questions on desirable macronutrient bal- while many can enable people to lose weight initially, ance are based on authoritative recommendations about some diets are nutritionally inadequate or recommend fat (36), carbohydrate (37) protein (25) and alcohol (38). strategies which are not supported by current public health They also reflect recommendations from DAA in relation guidelines (24,25). While several authors have attempted to to macronutrient balance in weight reduction diets (28). rate diets and give them a numerical score, they have not The recommendation on protein (12 to 25%E) is been explicit in the methods used, and there is no compre- somewhat tentative. The mean protein intake of Austral- hensive quantitative system that can be used to evaluate ian adults reported in the 1995 National Nutrition Survey new popular diet books. Such a tool would assist dietitians was 17.1%E (39). There is mounting evidence that protein and other health professionals in their role of helping con- intakes in excess of two to three times the RDI—which sumers to combat nutrition misinformation (26). equates to around 17 to 25%E—may be harmful (40). The aim of the present study was to develop a rating While there is one study that reported significantly greater systemthatcouldbeusedbyhealthprofessionalstoeval- weight loss from a diet providing 24%E in protein (41), uate popular diet books. A questionnaire was developed, there is no evidence of the long-term effectiveness of high incorporating quantified criteria, which was then tested protein diets and the target chosen is consistent with the for practicality, validity and sensitivity by evaluating 20 current advice for weight management from the popular diet books available in Australia in 2001. NHMRC (34). The final question in this section relates to Although some of the books promoted a variety of health the Better Health Commission’s target to increase the die- benefits in addition to weight management, for the pur- tary fibre content of the Australian diet to 30g per day (42).

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2. Energy allowance and recommended rate of weight loss the public to be wary if the author of a diet book made outlandish claims (29). The ADA has also warned consum- This section is given a total of ten marks, with two ques- ers about claims that sound too good to be true (32). tions, each worth five marks. The first question relates to Examples of unacceptable claims for diets include using the minimum daily energy prescription, while the second special combination of foods or supplements that would question concerns the promised rate of weight loss. A enable effortless weight loss. minimum daily energy intake of 1000 to 1200 Cal (4200 to 5000 kJ) is recommended for weight loss diets by the 7. Authors’ credentials National Health and Medical Research Council’s policy statement on slimming diets (33). This statement and oth- This section is worth a total of five marks. The ADA has ers also recommend no more than half to one kilogram of stressed the importance of checking the author’s qualifica- weight loss per week (43). Books that prescribed energy tions and advises that a reputable author is usually one intakes below 1000 Cal (4200 kJ) per day, or weight loss whose educational background and/or current affiliation is of greater than one kilogram per week lose marks in this with an accredited university or medical centre with pro- section. grams in nutrition, medicine, or a closely related discipline (48). The DAA has also recommended that con- 3. Flexibility and sustainability sumers look for authors who have recognised nutrition qualifications (29), as have other experts (24). Authors with This section is allocated a total of 15 marks. Three ques- university qualifications in nutrition are given the maxi- tions are asked, each related to an area that has been found mum score of five. Any author with university to be important for long-term, successful weight qualifications in medicine or physiology is given a control (15,16,23,44): slightly lower score of three. Authors with qualifications • inclusion of a wide variety of foods and allowance for in are not given any marks for this individual preference and taste question. • making permanent, realistic lifestyle changes • making appropriate behavioural changes. 8. Scientific evidence Those diets, which allow only a limited range of This last section is allocated a total of ten marks. It foods, are still given five marks for the first question in includes a question on whether the recommendations in this section if they provide useful advice on aspects such the book are based on published scientific evidence, rather as recipe modification. Diet books that include advice on than testimonials. A second question asks whether the supportive behavioural changes, such as ways to deal with author refers the reader to further credible sources of stress and depression, or ways to break unwanted habits nutrition information. The ADA has warned that case his- such as eating while watching television, are given a score tories, testimonials, and subjective evidence should be of five for the third question. viewed with scepticism, and that evaluation of nutrition information can only be done through proper interpreta- 4. Physical activity tion of scientific studies (48). This section contains two questions worth a total of ten Part 2: Applying the assessment questionnaire to marks. The questions are based on the National Physical review popular diet books Activity Guidelines for Australians, which recommend a minimum of 30 minutes of moderate intensity physical Twenty diet books were chosen for review, based on the activity on most, preferably all, days (45). advice of staff at local bookstores about the most popular titles (49–68) (see Table 1). In order to test the performance 5. Supplement recommendations of the questionnaire, a number of aspects were evaluated. This section contains one question and five marks are Practicality given if no supplements are recommended. The dietary guidelines for Australians indicate that supplements The energy content and macronutrient composition of should not be needed if a diet is nutritionally well each diet was calculated by dietary analysis of three days balanced (46) and ideally even a weight loss diet should be of each menu plan, using the FoodWorks nutrient analysis able to provide a nutritionally adequate diet without the software package (Xyris Software, Brisbane, FoodWorks need for vitamin or mineral supplements. The ADA has Nutrient Analysis Software, Brisbane version 2.0 1998) stressed that supplements should not be used as replace- with the AusNut food composition databases (Australia ments for nutrient-rich foods (32). A recent study that New Zealand Food Authority, Canberra: AUSNUT— reviewed the evidence for the effectiveness of popular, Australian Food and Nutrient Database; 1999). If analyti- non-prescription weight loss supplements in Australia cal data on foods were not available in AusNut, values concluded that there was no good evidence of any weight were taken from the NUTTAB95 database (NUTTAB95 loss benefits from most of the 15 substances in the Data Tables for Use in Australia. Canberra: Australian review (47). Government Publishing Service; 1995). Books that pro- vided multiple sample menus had the first three days 6. Claims menus analysed to calculate the macronutrient and energy content of the diets. Some books supplied menus but did Books are given five points if all claims made are sup- not specify serving sizes. In this situation, the average ported clearly by scientific evidence or public health serving sizes in the Foodworks program were used as the policy. Books making claims that are misleading, unsub- estimated amounts, although this may have underesti- stantiated by research, or purely anecdotal are given no mated the requirements for a more active person or for points. This is in line with the position of DAA, warning some males. Not all books contained sample menus, some

Nutrition & Dietetics (2003) 60:3 187 Evaluating popular diet books (a) Theory behind the diet Low CHO Low CHO, low fat Health requirements are determined by the stars High CHO, moderate protein, low fat Low CHO, high protein, high fat Very low fat (< 10%), high CHO Blood type determines diet. A: high CHO, low fat, vegetarian diet. B: varied diet. AB: combination of A and B diets. O: high protein, low CHO Author advocates low fat, increased protein and avoidance of starchy CHO after 3.00pm High CHO, moderate protein, low fat High CHO, moderate protein, low fat Average daily energy intake (Cal/kJ), based on analysis of 3 days’ menus 1724 Cal (7217 kJ) 506 Cal (2120 kJ) 1332 Cal (5577 kJ) 1254 Cal (5248 kJ) 1432 Cal (5994 kJ) 1204 Cal (5042 kJ) 1672 Cal (7000kJ) 1467 Cal (6141 kJ) 2511 Cal (10 512 kJ) 3175 Cal (13 293 kJ) 1469 Cal (6150 kJ) 1074 Cal (4496 kJ) 1036 Cal (4335 kJ) 1300 Cal (5441 kJ) 1229 Cal (5144 kJ) 1874 Cal (7846 kJ) 1546 Cal (6472 kJ) 1362 Cal (5703 kJ) 1492 Cal (6244 kJ) walking/low intensity Physical activity recommendations Increase incidental exercise Walking, swimming, golf, tennis 20 mins/day, three times weekly Increase incidental activity,add and 30–60 mins/day of walking Minimum 30 mins walking per day Walk 20–60 mins per day. Add moderate resistance training (e.g. light weights) Recommendations vary according to blood type. Approx 30 mins aerobic exercise recommended on most days for blood types O and B Walking and resistance training recommended 30 mins aerobic exercise per day. Increase incidental activity Certain rules must be followed to maximise fat burning (e.g. exercise 2–3 hrs after meals; weight training must be done after exercise) Supplements Not mentioned Not mentioned Vitamin, mineral and herbal supplements recommended Avoids reliance on supplements Sells and recommends many vitamins, minerals, low CHO bars, shakesbread and mixes Avoids reliance on supplements Variety of supplements recommended Variety of vitamin and mineral supplements recommended Avoids reliance on supplements Avoids reliance on supplements Author’s credentials Psychologist Cardiologist Astrologer Medical practitioner Medical practitioner Professorofmedicine Naturopath Fitness leader Personal trainer BSc Grad Dip Nutr. Dip and . MSc (Nutrition) 14-day medical diet Air signs diet Earth signs diet Fire signs diet Water signs diet Induction diet Ongoing weight loss diet Maintenance diet Type A diet Type AB diet Type B diet Type O diet Female plan Male plan Diet The Carbohydrate Addict’s Diet (49) The Complete Scarsdale Medical Diet (50) Diet Signs – The Health Signs Diet (51) The Diet that Works! (52) Dr Atkins’ New Diet Revolution (53) Eat More Weigh Less (54) Eat Right 4 Your Type (55) Fat Free Forever (56) Fat Loss For Life (57) The Fat Stripping Diet (58) al1 Summaryofthedietsevaluated Table1.

188 Nutrition & Dietetics (2003) 60:3 Evaluating popular diet books High CHO, moderate protein, low fat Excess weight is a symptom of liver dysfunction. Liver- cleansing foods enable the liver to efficiently metabolise fat Advocates a diet that is lowsaturated in and trans fattybut acids, which contains generous amounts of omega 3 and monounsaturated fats High CHO, moderate protein, low fat. Includes up to three glasses red wine/day Low CHO, high protein, high fat Very low fat, low-moderate protein, high CHO Low sugar, low GI.many Restricts healthy foods (e.g. carrots, potatoes, corn, beets, white rice) High CHO (high fibre, high water content), moderate protein, low fat Advocates 40% CHO, 30% protein, 30% fat to ensure the correct balance of insulinglucagon. Claims and that this enables more ‘good’ eicosanoids to be produced which aid weight control and immune function 1883 Cal (7880 kJ) 1916 Cal (8020kJ) 1481 Cal (6198 kJ) 1110 Cal (4647 kJ) 1558 Cal (6523 kJ) 1316 Cal (5507 kJ) 1968 Cal (8236 kJ) 1535 Cal (6424 kJ) 1714 Cal (7177 kJ) 1757 Cal (7356 kJ) 1930 Cal (8079 kJ) 966 Cal (4043 kJ) 1778 Cal (7441 kJ) 2131 Cal (8920 kJ) 817 Cal (3418 kJ) 1226 Cal (5131 kJ) 20 mins aerobic exercise per day Importance of aerobic & incidental exercise Acknowledges the importance of exercise but does not elaborate on this Minimum 45 mins exercise per day 30 mins aerobic exercisetimes 3–5 per week Acknowledges the importance of daily exercise but does not specify the amount required 30–60 mins of aerobic exercise per day 20 mins exercise atper least week 4 times Advice re: stretching, warming up, inclusion of some longer exercise sessions, varyingintensity, the trying weights Importance of aerobic exercise such as walking forjogging 6 for hrs or 3 hrs per week Claim that supplements are not needed & that fruits & veg contain all necessary nutrients Avoids reliance on supplements Sells and recommends many supplements Avoids reliance on supplements Daily multivitamin while dieting Avoids reliance on supplements Not mentioned Avoids reliance on supplements Avoids reliance on supplements Recommends various vitamins. Sells and recommends zone- favourable bars and powders Nutrition qualification from non-accredited institution Dietitian Medical practitioner Medical practitioner Chaired the Nutrition committee of the National Institute of Health Publisher: diet and fitness magazine Chiropractor Motivational speaker, owns an exercise studio Endocrinologist PhD Holds the Guthrie Chair of Nutrition at Penn State Uni PhD (biochemistry) 4800 kJ plan 6300 kJ plan 1400 calorie plan 2000 calorie plan 60 kg ideal weight 70 kg ideal weight 1750 calorie diet 1930 calorie diet 1600 calorie plan 2000 calorie plan 8 protein blocks 12 protein blocks (59) Licence to Eat (60) The Liver Cleansing Diet (61) The Omega Plan (62) Rosemary Conley’s Red Wine Diet (63) Slim Forever (64) Stop the Insanity! (65) Sugar Busters! (66) The Volumetrics Weight Control Plan (67) The Zone – A Dietary Road Map (68) (a) CHO = carbohydrate

Nutrition & Dietetics (2003) 60:3 189 Evaluating popular diet books merely provided a list of suggestions for each meal and ommended intake provided by each diet, based on the for snacks. In this case, the first three items on each of the nutrient analysis of three days of menus. breakfast, lunch and dinner lists were included in the anal- ysis. The first six items on the snack list were also A total of 35 diets from the 20 books were analysed. included (one for mid morning and the other for mid after- Only two (Licence to eat and The Volumetrics weight con- noon each day, if permitted). When recipes from the trol plan) supplied at least 100% of the RDI for all books were analysed, salt was not included unless specifi- nutrients. The nutrients that were provided below 100% of cally stated in a recipe. the RDI for women included zinc (low in 59% of the diets), iron (low in 41% of the diets), calcium (low in 38% of the diets) and magnesium (low in 29% of the diets). For Validity men, the following nutrients were often below the RDI: The calculated mean daily nutrient intakes based on the zinc (low in 53% of the diets), magnesium (low in 44% of three-day menus were compared to the recommended die- the diets), calcium (low in 38% of the diets), riboflavin tary intakes (RDI) for a male (assumed to have a height of (low in 35% of the diets) and thiamin (low in 26% of the 175. cm and a weight of 81.2 kg) and a female (163.1 cm diets). tall and weighing 64.3 kg) (69). These were the average heights and weights for males and females aged 25–44 Practicality years, reported in the 1995 National Nutrition Survey (70). In general the questionnaire was able be implemented eas- Values for dietary fibre intake were compared with the ily. However, the calculation of energy and macronutrient recommended intake of 30 g per day (42). content was not always straightforward and required some The validity of the nutritional adequacy section of the decisions to standardise the procedures, as described in the questionnaire (questions 1–10) was tested by comparing Methods section. A few specific procedures were adopted the nutrition sub-score (out of 40) with the maximum for individual diets: number of nutrients found to be provided at less than 100% or 70% of the RDI, for either the reference man or The carbohydrate addict’s diet: woman. The daily menu plans only specified the foods to be included at breakfast and lunch. The other daily Sensitivity ‘reward meal’ could include anything, however the Ideallyanassessmentmethodshouldbeabletodiscrimi- authors recommend the use of low-fat dairy, lean nate between the quality of different diets across a wide meat/fish/poultry, vegetables/salad, whole grains, and numerical range, so that diets can be categorised easily fruits at the reward meal. Reward meals for analysis into broad bands that relate to their acceptability. The final were chosen with these recommendations in mind, but overall scores were examined to measure the range of the obviously may not be typical of the foods chosen by scores and whether they could categorised into bands for other people. summary descriptions of the diets as recommended, ade- The liver cleansing diet and Eat right 4 your type: quate, or not recommended. The fat and calcium content of soy milk was not speci- Statistical analysis fied in either book. Calcium-fortified, full-cream soy milkwasusedintheanalyses. Statistical analyses were undertaken using SPSS for Win- dows 11.0 (SPSS Inc, Chicago, SPSS for Windows, Stop the insanity!: version 11.0 2002). The relationships between the overall No sample meal plan was included in the book. The score (out of 100) or the nutrition sub-score (out of 40) author provides a few meal suggestions and examples and the numbers of nutrients likely to be provided at of foods that she sometimes eats. The analysis was < 70% RDI or < 100% RDI were assessed by calculation based on these foods. The author recommends approx- of the Spearman’s rank correlation coefficient. One-way imately 1750 calories (7350 kJ) for a 64.3 kg female analysis of variance with Bonferroni post-hoc comparison and 1930 calories (8100 kJ) for an 81.2 kg male, so was used compare the mean scores of books written by each of the three days’ diets were constructed to be as those with nutrition qualifications, those with medical close as possible in energy content to these qualifications, and others. For this comparison, the total recommendations. scores were adjusted to exclude the maximum score of five related to author’s qualifications. A significance level Fat free forever: of < 0.05 was applied to all statistical tests. The author recommends one ‘junk food’ meal per week to ‘speed up the metabolism’. The reader is Results encouraged to eat ‘anything from pizza to pasta with cream, or fried chicken and a chocolate sundae’. The analysis included two days of the Fat Free Forever Description of the diets and nutrient adequacy diet, plus one with a ‘junk food’ meal (three slices of Table 1 lists the books that were reviewed, author details pizza and a milkshake), but this may not be typical of and a summary of the approaches taken to weight loss the choices made by other readers. management. The scores in each category of assessment Licence to eat: and the total score of each book out of 100 are shown in Table 2. Table 3 sets out the nutrients potentially at risk in The book did not contain a specific menu plan. Foods each diet, expressed as the percentage of adult daily rec- were chosen from the author’s lists of ideas for each

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Table 2. Rating of the 20 diet books (ranked from highest to lowest by total score) Flexibility Nutritional Energy and Physical Authors’ Scientific Total adequacy(a) allowance sustainability activity Supplements Claims credentials evidence score(b) Diet (max 40) (max 10) (max 15) (max 10) (max 5) (max 5) (max 5) (max 10) (max 100) The volumetrics weight 35–39 10 15 10 5 5 5 10 97 control plan Licence to eat 36 10 15 10 5 5 5 10 96 Fat loss for life 32 10 15 10 5 5 5 5 87 The diet that works! 32 10 15 10 5 5 3 5 85 Eat more weigh less 32 10 15 10 5 5 3 5 85 The fat stripping diet 23–27 10 15 10 5 5 5 5 80 The omega plan 12–23 10 15 10 5 5 5 10 78 Stop the insanity! 32–36 10 10 10 5 0 0 5 74 Rosemary Conley’s red 8–15 10 15 10 5 5 0 5 62 wine diet Fat free forever 19 10 15 10 0 5 0 0 59 Diet signs—The health 8–19 10 10 5 0 5 0 0 45 signs diet The complete Scarsdale 16 0 10 10 5 0 0 0 44 medical diet The carbohydrate addict’s 8 10 15 5 5 0 0 0 43 diet The liver cleansing diet 24 5 5 5 0 0 3 0 42 The zone—A dietary road 12–16 5 10 10 0 0 3 0 42 map Fit for life 16 5 10 5 5 0 0 0 41 Sugar busters! 12 5 10 5 5 0 3 0 40 Eat right 4 your type 12–16 10 5 5–10 0 0 0 0 36 Dr Atkins’ new diet 8–16 5 5 10 0 0 3 0 35 revolution Slim forever 12 5 5 5 5 0 0 0 32 (a) Range shown where several diet plans are given in the one book. (b) Total score calculated using the mean nutritional adequacy score.

meal. Adjustments were made to ensure that ten fibre- • ‘it is not only what you eat that makes the difference, serves, three to four calcium serves, and three iron but also of extreme importance is when you eat and in serves were chosen each day, in accordance with the what combinations’. author’s recommendations. The section of the questionnaire relating to evaluation Validity of the claims made about the diet required professional Table 4 compares the nutrition scores from the first ten judgement. This introduces some lack of precision into questions (maximum score 40) and the nutritional ade- the tool and makes it unsuitable to be used by the general quacy of the diets, as assessed by the number of nutrients public in the current form. However, this question that were provided in quantities less than 70% or less than accounts for only five percent of the final total score. 100% RDI. There was a strong correlation with both Examples of claims in the books that were classified as measures (Spearman’s rho = -0.671 and -0.731 respec- unacceptable were: tively; P < 0.01), suggesting that the ten questions provide • ‘a carbohydrate-restricted diet is so effective at dis- a good indication of the nutritional adequacy of the diets. solving adipose tissue that it can create fat loss greater There was also a strong correlation between the number of than occurs in ’; nutrients that were provided in quantities less than 70% or • ‘wheneatenonanemptystomach,freshfruitcan less than 100% RDI and the overall rating score out of 100 have only a positive effect; it accelerates weight loss’; (Spearman’s rho = -0.618 and -0.653; P < 0.01). Such a correlation is to be expected given the fact that the nutri- • ‘the key to successful weight loss and maintenance is tion sub-score makes up 40% of the overall rating score. to restore efficient liver function’

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Table 3. Nutrients potentially at risk in 20 popular diets: percentage of adult daily recommended intake provided by each diet calculated from analysis of 3 days of menus(a) Diet Fibre Vit A Vit B1 Vit B2 Vit C Folate Ca Mg Zn Fe K P The Carbohydrate Addict’s Diet 48 79 84 68 74 66 85 The Complete Scarsdale Medical Diet 33 37 30 82 23 39 54 48 95 60 Diet Signs—The Health Signs Diet Air signs diet 73 96 87 94 Earth signs diet 87 95 Fire signs diet 79 65 83 Water signs diet 63 58 93 92 88 The Diet that Works! 69 82 Dr Atkins’ New Diet Revolution Induction diet 13 47 77 72 99 89 54 96 72 98 Ongoing weight loss diet 41 75 86 Maintenance diet 80 98 Eat More Weigh Less 75 87 71 Eat Right 4 Your Type Type A diet 56 81 61 81 90 58 Type AB diet 65 70 76 91 55 Type B diet 52 71 84 64 80 Type O diet 68 79 62 50 93 88 Fat Free Forever 80 Fat Loss For Life 97 95 84 The Fat Stripping Diet Female plan 80 80 92 Male plan 89 99 83 Fit For Life 73 64 72 Licence to Eat The Liver Cleansing Diet 73 84 The Omega Plan 4800kJ plan 54 78 53 68 58 66 6300kJ plan 89 62 80 82 87 96 Rosemary Conley’s Red Wine Diet 1400 calorie plan (female) 60 59 89 92 2000 calorie plan (male) 87 Slim Forever 60 kg ideal weight (female) 26 83 36 60 67 59 70 kg ideal weight (male) 31 82 92 44 58 81 Stop the Insanity! 1750 calorie diet (female) 85 41 99 1930 calorie diet (male) 65 44 Sugar Busters! 58 65 73 66 77 65 72 The Volumetrics Weight Control Plan The Zone—A Dietary Road Map 8 protein blocks (female) 47 45 82 65 62 12 protein blocks (male) 66 56 97 (a) Male adult Australian RDI used as reference unless specified, except for iron where female RDI used as standard (69). 30 g per day used as reference value for dietary fibre (42). No entry in table and other nutrients not included in table indicates nutrient provided at greater than 100% RDI.

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Table 4. Relationship between nutrition score and struct a more refined scoring system depending on how nutrients at risk in 20 popular diet books, as close the diet was to the target, in the way that the US assessed by three-day diet analysis Healthy Eating Index was constructed (71),butitwas Mean number of Mean number of decided not to adopt this approach in order to reduce the Nutritional adequacy nutrients less nutrients less than complexity of the scoring. score(outof40) than 70% RDI 100% RDI 31–40 (n = 6) 0 1 The validity of the nutrition component of the ques- tionnaire was evaluated by examining how well the scores 21–30 (n = 2) 0 2 correlated with nutritional adequacy determined by analy- 11–20 (n = 11) 2 4 sis of three days of the diet plans, a method that has been 1–10 (n = 1) 3 6 used to validate other assessment tools (71,72). While the two scores do not measure precisely the same aspects of the diet, they both relate to overall nutritional quality. The results in Table 4 provide reassurance that the semi-quali- Sensitivity tative assessment of the diet, using the questions about food groups and macronutrient targets in the question- Among the 20 books evaluated there was a wide range of naire, is meaningful when evaluated in terms of the scores, from 32 to 97. This indicates that the evaluation quantitative assessment of provision of nutrients. tool is capable of discriminating between the books in a useful way. Using the detailed nutritional assessments as a It must be acknowledged it can be difficult to ensure guide to the overall adequacy, the following bands of 100% RDI is met for all micronutrients when planning ranking the total scores can be suggested: energy restricted diets. Indeed with some low energy diets 81–100: Recommended it may be appropriate to recommend a general vitamin and mineral supplement to ensure all requirements are met. 61–80: Adequate (but some areas need However it is notable that with one minor exception none improvement) of the books that scored above 80 provided less than 70% 1–60: Not recommended RDI for any nutrient and only a few were marginally This division is somewhat arbitrary, but the five diets below the RDI for nutrients like zinc and calcium. The recommendations for these nutrients are among the most which achieved an overall rating of greater than 80 had a difficult to meet using basic unfortified foods (73),and mean nutrition score of 34 out of 40 and provided 100% of all nutrients—or at most two between 70 and 90% RDI slight deficits are unlikely to be nutritionally significant, (either zinc or calcium). The sole exception was The diet especially when energy reduction diets are not usually that works! which provided just 69% of the riboflavin intended for lifelong use. RDI for males. Those books with a total score of 60 or It is not possible to make direct comparisons of the less had a mean nutrition score of only 15 out of 40 and an scores using this method with other evaluations made of average of three nutrients provided at less than 70% RDI. popular weight loss diets, however the results are gener- There was a significant difference in the scores of ally consistent with other assessments. Berland in his books according to the authors’ qualifications. Consider- 1983 review rated the revolution as not recom- ing the total score without the five points related to author mended and the was given a rating of two qualifications (i.e. out of a maximum of 95 only), books stars (out of four), which compare with the ratings of 35 by those with recognised tertiary nutrition qualifications and44(outof100)respectivelygivenwithour (n = 5) had a mean score of 83, those by medical practi- method (16). In a more recent Australian nutrition book, tioners (n = 6) had a mean score of 52, and those by other the following diets are criticised for incorrect or unbal- authors (n = 9) scored 48. The differences between the anced advice, which is consistent with the fact that none scores of the books by nutrition authors and both other scored above 60 in the assessment reported here (scores groups were significant (P < 0.02), but the difference shown after each): Sugar Busters (40), Fit for Life (41), between medical and other authors was not. Eat Right 4 Your Type (36), Dr Atkins’ New Diet Revolu- tion (35) (74).

Discussion Nutrition and exercise advice Given that there is no gold standard by which to assess In one instance, the percentage of energy from carbohy- popular diet books, the scoring system used in this tool is drate, protein and fat (analysed by computer program) rather arbitrary. The weighting of values given to the dif- was different from the figures quoted by the author. Barry ferent sections of the rating score was based on the Sears, author of The zone—A dietary road map, claimed judgement of the authors. In particular it was decided that that the key to permanent weight loss and optimal health the nutritional scores and scientific evidence (which is consumption of a diet containing 40%E carbohydrate, together make up half of the overall rating) should pre- 30%E protein, and 30%E fat. Analysis of three days of dominate, in order that those using recommended diets menus from the diet indicated they provided 35%E carbo- can be confident that they are safe and nutritionally hydrate, 39%E protein, and 25%E fat. This discrepancy adequate. has been noted by other authors (75). For the sake of simplicity, most of the nutrition sub- Thirteen diets in eight books contained a higher per- scores were scored either as zero or full marks. For exam- centage of energy from protein than the target of 12 to ple, if the diet included at least five serves of vegetables 25%. Seven diets contained 30% energy or more from per day it achieved a score of four, if less than five were protein and less than 40% from carbohydrate. Low carbo- included the score was zero. It would be possible to con- hydrate diets often result in initial rapid weight loss,

Nutrition & Dietetics (2003) 60:3 193 Evaluating popular diet books however this is mainly due to excessive water loss rather Few authors recommended a medical check up prior to than loss of body fat. Possible complications of low-car- commencing an exercise program. bohydrate, high-protein diets include ketosis, dehydration, loss of electrolytes, calcium depletion, weakness, nausea In general the level of energy prescribed was reasona- and possibly kidney problems. People following these ble. Three diets, The Complete Scarsdale Medical Diet, diets are also at risk of inadequate vitamin and mineral Sugar Busters and The , contained less than 4200 kJ per day, and five promised undesirably rapid rates intake (25) and a review of the outcomes of popular diets reported that lower scores on a healthy eating index were of weight loss—The Complete Scarsdale Medical Diet, Dr Atkins’ New Diet Revolution, Fit for Life, The Liver associated with low-carbohydrate diets (76). Controlled studies have not shown any significant differences in Cleansing Diet, and Slim Forever. weight loss when low and high carbohydrate hypocaloric diets were compared (77) and the results of several studies Flexibility and sustainability have refuted the contention that low carbohydrate diets, in Every diet made some allowance for individual preference the absence of energy restriction, provide a metabolic and taste by offering a variety of options, even though advantage for weight loss (76). For all these reasons the some diets contained only a limited range of foods. Ten NHMRC has concluded that there is no long-term evi- diets achieved the maximum score of 15 for overall flexi- dence supporting the use of ‘popular’ low carbohydrate or bility and sustainability (see Table 2). high protein diets (34). It is still not proven that dramatic manipulation of the Authors’ credentials and scientific evidence macronutrient balance of the diet will have substantial The two books with the highest overall scores (> 95) were effects on weight loss. Energy restriction remains the key written by a professor of nutrition and a dietitian, but only variable associated with weight loss in the short term (76) five authors overall had university qualifications in nutri- and those most likely to be successful at long-term weight tion. It might be argued that authors’ credentials should control are those following a low-fat low energy diet (78). not be included in the total assessment score since the Researchers recently analysed the diets of more than 2600 value of nutrition expertise should be assessable by the members of the US National Weight Control Registry, dietary advice provided. In practice this sub-score had no who had maintained a weight loss of at least 30 pounds effect on the final ranking of the books, but because it is a (approximately 13.6 kg) for one year or longer. Although factor recommended for consideration by many high protein diets have been used for more than 30 years, experts (8,24,29,48) it has been left in the final assessment the researchers found that less than 1% of successful diet- tool. ers had followed a high protein diet and concluded that such diets may not create any metabolic advantage (79). Only three books received the maximum marks for the two questions relating to evidence: Licence to eat, The One book (Fit for life) promoted a diet that was found Volumetrics weight-control plan,andThe omega plan. to be low in protein (< 10%E). It was a food-combining Most relied on unreferenced or unsubstantiated claims. diet, which involved eating mainly fruit and vegetables. Low-energy food-combining diets have not been found to provide any metabolic benefits over low-energy balanced Conclusions diets in terms of weight loss, blood pressure, fasting The questionnaire developed here has been found to be plasma glucose, cholesterol or triglyceride levels (80).It practical and potentially useful in providing a quantitative has been argued that food-combining may create deficien- assessment of the adequacy and sustainability of the cies in zinc, vitamin B12, protein and calcium due to the advice provided in popular diet books. Further research is elimination of major food groups (81). required to assess its reproducibility when used by differ- Almostonethirdofthedietswerehighinfat ent assessors. Applying the questionnaire to a sample of (> 30%E), while 11 diets (in seven books) contained more currently popular diet books it was found that 11 out of 20 than 300 mg of cholesterol per day. Fourteen diets (ten books could not be recommended (with scores of 60 or books) contained more than 2300 mg of sodium. Some less out of 100). The findings from this study are similar diets took the low-fat recommendation to excess, with two to those from previous studies and reviews which have of the diets (Eat More Weigh Less; Stop the Insanity!) found many fad diets to be lacking in both nutritional ade- providing less than 10%E from fat. Although diets high in quacy, and without scientific evidence (15,16,22,24). dietary fibre have been shown to help reduce food The questionnaire described here may be useful for intake (82), the majority of these diets provided less than dietitians and other health professionals who want to eval- 30 g of dietary fibre per day, with the low carbohydrate uate diet books or make recommendations about the diets supplying the least amount. development of new diets. Accurate advice to the public is Six books relied on special supplements or products. A an essential part of any strategy to address the national review of potential supplements to assist weight reduc- obesity problem (83) and it is the responsibility of nutrition tion, conducted in developing the NHMRC draft clinical scientists to speak out about questionable nutrition advice, guidelines for weight control, concluded there is no con- particularly that which has not been proven to be safe (84). vincing evidence that any popular supplements are As the questionnaire requires the skills of a trained profes- necessary or assist weight loss (34). sional to carry out the nutrient analysis and make some judgements about the claims made, in its current form it is All diet books mentioned the need for physical activ- not a tool that can be used by members of the public to ity. Fourteen of the books contained exercise suggestions assess books themselves. In the future, it would be useful that were consistent with the recommendations from the to refine this method to develop a simpler version that National Physical Activity Guidelines for Australians (45). couldbeusedbyconsumersdirectly.

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References 27. Somer E. Nutrition for women. Melbourne: Bookman Press; 1993. 1. World Health Organization. Obesity: preventing and managing the 28. Dietitians Association of Australia. High protein diets [media state- global epidemic. Technical Report Series 894. Geneva: WHO; ment]. Canberra: DAA; 2000. 2000. 29. Dietitians Association of Australia. Dietitians warn against diet rip 2. Australian Institute of Health and Welfare. Australia's Health 2002. offs [media release 13 February 2001]. Canberra: DAA; 2001. Canberra: AIHW; 2002. 30. Dietitians Association of Australia. Dietitians Association warns 3. Crawford D, Campbell K. Men's and women's dieting beliefs. Aust against popular soup diet [media release 14 March 2001]. Canberra: J Nutr Diet 1998;55:122–9. DAA; 2001. 4. O'Dea J, Abraham S, Heard R. Food habits, body image and weight 31. Ashley J, Jarvis W. Position of the American Dietetic Association: control practices of young male and female adolescents. 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FAO Food and 12. Egger G, Mowbray G. A qualitative analysis of obesity and at-risk Nutrition Paper No 66. Rome: Food and Agriculture Organization; overweight in working men. Aust J Nutr Diet 1993;50:10–4. 1998. 13. Brownwell K, Rodin J. Medical, metabolic and psychological 38. National Health and Medical Research Council. Australian alcohol effects of weight cycling. Arch Intern Med 1994;154:1325–30. guidelines. Canberra: NHMRC; 2001. 14. Lissner L, Odell P, D'Agostina R, Stokes J, Kreger B, Belanger A. 39. McLennan W, Podger A. National Nutrition Survey. Selected High- Variability of body weight and health outcomes in the Framingham lights 1995. ABS Catalogue No 4802.0. Canberra: Australian population. New Eng J Med 1991;324:1839–44. Bureau of Statistics; 1997. 15. Stanton R. The Diet Dilemma—explained. Sydney: Allen and 40. Eisenstein J, Roberts S, Dallal G, Saltzman E. High-protein weight Unwin; 1991. loss diets: are they safe and do they work? A review of the experi- 16. Berland T. Rating the diets. New York: Signet; 1983. mental and epidemiological data. Nutr Rev 2002;60:189–200. 17. Van Tuinen I. Rating the diet books. Nutrition Action Newsletter. 41. Skov A, Toubro S, Ronn B, Holm L, Astrup A. Randomized trial on May 2000. http://www.csinet.org/nah/5_00/diet.html. Accessed 12 protein vs carbohydrate in ad libitum fat reduced diet for the treat- February 2002. ment of obesity. Int J Obes Rel Metab Dis 1999;23:528–36. 18. Anderson J, Konz E, Jenkins D. Health advantages and disadvan- 42. Better Health Commission. Looking forward to better health. Vol 2. tages of weight-reducing diets: a computer analysis and critical The taskforces and working groups: reports to the Better Health review. J Am Coll Nutr 2000;19:578–90. Commission. Canberra: Australian Government Publishing Serv- ice; 1986. 19. Riley R. Popular weight loss diets. Health and exercise implica- tions. Clin Sports Med 1999;18:691–701. 43. Expert panel on the identification, evaluation and treatment of over- weight in adults. Clinical guidelines on the identification, 20. Leibman B. Diet Vs Diet (weight-reducing diets). Nutrition Action evaluation, and treatment of overweight and obesity in adults: exec- Newsletter. May 2000. http://www/hcrc.org/contrib/coleman/quest- utive summary. Am J Clin Nutr 1998;69:899–917. books.html. Accessed 12 February 2002. 44. Egger G. Trim for life. Sydney: Allen and Unwin; 1997. 21. Coleman E. Questionable Weight loss books. 2001. http://www.hcrc/contrib/coleman/questbooks.html. Accessed 4 45. Commonwealth Department of Health and Aged Care. National August 2001. physical activity guidelines for Australians. Canberra: Common- wealth Department of Health and Aged Care; 1999. 22. Freedman M, King J, Kennedy E. Popular diets: a scientific review. Obes Res 2001;9(Suppl 1):1S–40S. 46. National Health and Medical Research Council. Dietary Guidelines for Australians. Canberra: Australian Government Publishing Serv- 23. Egger G, Swinburn B. The fat loss handbook—A guide for profes- ice; 1992. sionals. Sydney: Allen and Unwin; 1996. 47. Egger G, Cameron-Smith D, Stanton R. The effectiveness of popu- 24. Roberts D. Quick weight loss: sorting fad from fact. Med J Aust lar, non-prescription weight loss supplements. Med J Aust 2001;175:637–40. 1999;171:604–8. 25. St Jeor S, Howard B, Prewitt T, Bovee V, Bazzarre T, Eckel R. Die- 48. American Dietetic Association. Position of the American Dietetic tary protein and weight reduction. A statement for healthcare Association: Identifying food and nutrition misinformation. JAm professionals from the Nutrition Committee of the Council on Diet Assoc 1988;88:1589–91. Nutrition, Physical Activity, and Metabolism of the American Heart Association. Circulation 2001;104:1869–74. 49. Heller R. The carbohydrate addict's diet. Ringwood: Penguin Books Aust Ltd; 2000. 26. Williams P. Combating nutrition misinformation. In: Proceedings of the New Zealand Dietetic Association. 2001: Christchurch; 50. Tarnower D, Sinclair Baker S. The complete Scarsdale medical NZDA. diet. New York: Bantam Books; 1980.

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51. Petulengro C. Diet signs—the health signs diet. London: Pan 71. Kennedy E, Ohls J, Carlson S, Fleming K. The healthy eating Books; 2000. index: Design and applications. J Am Diet Assoc 1995;95:1103–8.

52. Hayes M. The diet that works! Ringwood: Penguin Books Aust 72. Hann C, Rock C, King I, Drenowski A. Validation of the Healthy Ltd; 1999. Eating Index with use of plasma biomarkers in a clinical sample of women. Am J Clin Nutr 2001;74:479–86. 53. Atkins R. Dr Atkins' diet revolution. New York: Avon Books; 1992. 54. Ornish D. Eat more weigh less. Melbourne: Bookman Press; 1993. 73. Cashel K, Jeffreson S. The core food groups. The scientific basis for developing nutrition education tools. Canberra: National Health 55. D'Adamo P, Whitney C. Eat right 4 your type. London: Century and Medical Research Council; 1995. Books Ltd; 1998. 74. Saxelby C. Nutrition for life. Melbourne: Hardie Grant Books; 56. Barker D. Fat free forever. Sydney: Random House; 1996. 2002.

57. Lococo S, Morelli S. Fat loss for life. Melbourne: S and I Publish- 75. Cheuvront S. The Zone diet and athletic performance. Sports Medi- ing Pty Ltd; 1999. cine 1999;27:213–28. 58. Bilsborough S. The fat stripping diet. Sydney: Penguin Books Aust 76. Kennedy E, Bowman S, Spence J, Freedman M, King J. Popular Pty Ltd; 2001. diets: correlation to health, nutrition and obesity. J Am Diet Assoc 59. Diamond H. Diamond M. Fit for life. Sydney: Harper Collins; 2001;101:411–20. 1994. 77. Golay A, Eigenheer A, Morel Y, Kujawski P, Lehmann T, de 60. Duncanson K. Licence to eat. Yarralumla: RWM Publishing Pty Tonnac N. Weight-loss with low or high carbohydrate diet? Int J Ltd; 1998. Obes 1996;20:1067–72.

61. Cabot S. The liver cleansing diet. Sydney: WHAS Pty Ltd; 1996. 78. Schick S. Persons successful at long-term weight loss and mainte- nance continue to consume a low-energy, low-fat diet. JAmDiet 62. Simonopoulos A, Robinson J. The omega plan. Sydney: Hodder Assoc 1998;98:408–13. and Stoughton; 1998. 63. Conley R. Rosemary Conley's red wine diet. London: Random 79. Wyatt H, Seagle H, Grunwald G, Bell M, Klem M, Wing R, et al. House; 2000. Long term weight loss and very low carbohydrate diets in the National Weight Control Registry. Obes Res 2000;8(Suppl 1):87S. 64. Harris R. Slim forever. Runaway Bay: Sunshine Publications; 2000. 80. Golay A, Allaz A, Ybarra J, Bianchi P, Saraiva S, Mensi N. Similar 65. Powter S. Stop the insanity! Maryborough: Orion Books Ltd; 1994. weight loss with low energy food combining or balanced diets. Int J Obes 2000;24:492–6. 66. Andrews S, Balart L, Bethea M, Steward H. Sugar busters! London: Vermillion; 1998. 81. Coleman E. The fit for life diet. 2001. //http://www.hcrc.org/con- 67. Rolls B, Barnett R. The Volumetrics weight-control plan. New trib/coleman/fit4lif2.html. Accessed 4 August 2001. York: Harper Collins; 2000. 82. Rolls B. Carbohydrates, fats, and satiety. Am J Clin Nutr 68. Sears B. The zone—A dietary road map. New York: Harper Col- 1995;61(Suppl 4):960S–7S. lins; 1995. 83. National Health and Medical Research Council. Acting on Aus- 69. National Health and Medical Research Council. Recommended tralia's weight: A strategic plan for the prevention of overweight Dietary Intakes for Use in Australia. Canberra: NHMRC; 1991. and obesity. Canberra: Australian Government Publishing Service; 1997. 70. McLennan W, Podger A. National Nutrition Survey. Nutrient intakes and physical measurements. ABS Catalogue No 4805.0. 84. Herbert V. Will questionable nutrition overwhelm nutrition sci- Canberra: Australian Bureau of Statistics; 1998. ence? Am J Clin Nutr 1981;34:2848–53.

Appendix 1. Diet rating questionnaire SCORE Nutritional adequacy (maximum score = 40) 1. Does the diet include at least 4 serves of bread/cereals per day for women, or 6 serves for men? (Yes = 4)_____ 1serve= 2 slices (60 g) bread, 1 medium bread roll 1 cup (180 g) cooked rice, pasta, noodles 1 cup (230 g) cooked porridge 1/ 1 3 cups (40 g) cereal flakes or ready to eat cereal ½ cup (65 g) untoasted muesli 1/ 3 cup (40 g) flour 2. Does the diet include at least 5 serves of vegetables, legumes per day? (Yes = 4)_____ 1serve= ½ cup (75 g) cooked vegetables, cooked dried beans, peas or lentils 1cupsaladvegetables 1 small potato 3. Does the diet include at least 2 serves per day of fruit? (Yes = 4)_____ 1serve= 1 medium piece (150 g) of fruit (apple, banana, orange, pear) 2 small pieces (150 g) of fruit (apricots, kiwifruit, plums) 1 cup (150 g) diced pieces or canned fruit 1½ tablespoons sultanas, 4 dried apricot halves ½ cup (125 ml) fruit juice

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4. Does the diet include at least 2 serves per day of milk, yoghurt or cheese? (Yes = 4)_____ 1serve= 1 cup (250 mL) fresh, longlife or reconstituted dried milk 1cup(250mL)soymilk(fortifiedwithatleast100mgcalcium/100ml) ½ cup (125 mL) evaporated milk 2 slices (40 g) cheese 1 small carton (200 g) yoghurt 1 cup (250 mL) custard 5. Does the diet include at least 1 serve per day of meat, fish, poultry, eggs, nuts, legumes? (Yes = 4)_____ 1serve= 65–100 g cooked meat, chicken (e.g. ½ cup lean mince, 2 small chops, 2slicesroastmeat) 1/ 3 cup peanuts, almonds or ¼ cup sunflower seeds, sesame seeds 6. Does the diet provide 30% or less energy from fat (with < 10% saturated and trans fatty acids)? (Yes = 4)_____ 7. Does the diet provide adequate carbohydrate intake? (a) 55–60% energy from carbohydrate (Yes = 4)_____ (b) 50–54% energy from carbohydrate (Yes = 3)_____ 8. Does the diet provide 12–25% energy from protein? (Yes = 4)_____ 9. Does the diet limit alcohol intake? (Yes = 4)_____ (Max 2 standard drinks per day; 1–2 alcohol-free days per week) 10. Does the diet provide adequate dietary fibre intake? (a) 30 g or more dietary fibre per day (Yes = 4) (b) 25–29 g of dietary fibre per day (Yes = 3)_____ Energy allowed and recommended rate of weight loss (maximum score = 10) 11. Does the diet contain a minimum of 4200 kilojoules per day? (Yes = 5)_____ 12. Is the promised rate of weight loss no more than 1 kilogram per week? (Yes = 5)_____ Flexibility and sustainability (maximum score = 15) 13. Does the diet allow for individual preference and taste? (Yes = 5)_____ 14. Does the diet encourage permanent, realistic lifestyle changes, enabling it to be followed long term? (Yes = 5)_____ (e.g. does it suggest ways to incorporate exercise into a busy lifestyle, or provide advice on the most appropriate choices to make when dining out?) 15. Does the diet provide advice on supportive behavioural changes rather than merely advising which foods to choose or limit? (Yes = 5)_____ (e.g. does it suggest alternative methods for dealing with stress or depression, or provide suggestions on how to break unwanted habits such as eating while reading or watching television?) Physical activity (maximum score = 10) 16. Does the author discuss the importance of physical activity for effective weight control? (Yes = 5)_____ 17. Are people advised to carry out at least 30 minutes of moderate-intensity physical activity on most, preferably all, days? (Yes = 5)_____ Supplement recommendations (maximum score = 5) 18. Does the diet avoid reliance on special supplements or products? (Yes = 5)_____ Claims (maximum score = 5) 19. Does the author avoid making exaggerated claims, promoting the diet in an extravagant way? (Yes = 5) _____ (e.g. faster weight loss than any other method; no need to restrict amount of food eaten) Authors’ credentials (maximum score = 5) 20. Do the authors have appropriate educational qualifications? (a) University qualifications in nutrition or dietetics? (Yes = 5)_____ (b) University qualifications in medicine or physiology? (Yes = 3)_____ Scientific evidence (maximum score = 10) 21. Are the recommendations based on published scientific evidence, rather than testimonials? (Yes = 5) _____ 22. Does the author refer the reader to other credible sources of nutrition information? (Yes = 5) _____ (e.g. the Dietitians Association of Australia or the National Heart Foundation) Total rating for the diet (max = 100)____

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