Appetite 44 (2005) 283–288 www.elsevier.com/locate/appet Research Report Self-set dieting rules: Adherence and prediction of weight loss success Ba¨rbel Kna¨uper*, Surkhraj Cheema, Marjorie Rabiau, Odelia Borten Department of Psychology, McGill University, Montreal, Que., Canada Received 21 September 2004; revised 15 November 2004; accepted 25 January 2005 Abstract The low achievement rates among dieters could be partially due to ineffective dieting strategies, or an inability to adhere to them in the long term. The present research examines the effectiveness of self-set dieting rules for achieving dieting goals. Specifically, it investigates how the types of dieting rules and the extent to which dieters adhere to them predict dieting success. A prospective study with reassessment after two months was conducted and analyzed in 2003. Participants were 132 currently dieting females recruited on a university campus. They completed measures assessing self-set dieting rules, dieting goal, and height and weight at Time 1 and Time 2. Data were analyzed using c2 tests and multiple linear regression. Overall, adherence to self-set dieting rules was markedly low. Reduction of caloric intake and increase of exercise predicted weight loss success. Sustained adherence to the dieting rules ‘reducing calories’ and ‘increasing exercise’ was found to be effective for achieving self-set dieting goals. The findings suggest that encouraging long-term adherence to effective rules could help increase the number of successful self-controlled dieting efforts. q 2005 Elsevier Ltd. All rights reserved. Keywords: Dieting rules; Self-controlled; Weight loss; Adherence; Self-regulation Introduction a formal weight loss program (Kruger et al., 2004; Paeratakul et al., 2002). For example, a recent survey It is currently estimated that one in three adults in the found that only 4.5% of dieters in a US representative United States is trying to lose weight (Jeffery, Adlis, & sample attempted to lose weight by joining an organized Forster, 1991; Kruger, Galuska, Serdula, & Jones, 2004; weight-loss program (Kruger et al., 2004). Paeratakul, York-Crowe, Williamson, Ryan, & Bray, 2002; Rules followed as part of a self-controlled weight loss Serdula, Mokdad, Williamson, Galuska, Mendlein, & effort are far ranging (French, Jeffery, & Murray, 1999; Heath, 1999). Dieting attempts, however, frequently remain Kruger et al., 2004), and can include strategies such as unsuccessful. Within five years the majority of dieters will taking laxatives, diet pills or vomiting (French et al., 1999). regain the weight they originally lost and after five years Nonetheless, the vast majority of dieters have been found to they often exceed their initial weight (Crawford, Jeffery, & engage mostly in healthful dieting strategies such as French, 2000; National Task Force on the Prevention and reducing fat or increasing exercise (French et al., 1999; Treatment of Obesity, 1993). The low achievement rates Kruger et al., 2004). Little is known, however, about the among dieters could be partially due to ineffective dieting effectiveness of such self-set dieting rules for losing weight. strategies and partially to an inability to adhere long-term to Knowing which rules are effective in a self-controlled effective strategies (Dean, 2000). weight loss effort may help in understanding the factors that Survey results show that most people attempt to lose hinder individuals in successfully achieving a healthier weight by following self-set dieting rules rather than joining body weight. The present study uses a prospective design to examine the effectiveness of self-set dieting rules for achieving * Corresponding author. weight loss goals. Specifically, it investigates how the types E-mail address: [email protected] (B. Kna¨uper). of dieting rules people set for themselves, and the extent to 0195-6663/$ - see front matter q 2005 Elsevier Ltd. All rights reserved. which people adhere to these dieting rules, are related to doi:10.1016/j.appet.2005.01.008 dieting success. 284 B. Kna¨uper et al. / Appetite 44 (2005) 283–288 Past research The present study Past studies have used cross-sectional retrospective The present research examines self-set dieting rules in a research designs or asked only general questions about sample of dieting women who were asked to list, in an open eating and exercise behaviors or assessed dieting strategies response format, up to eight dieting rules they follow in in samples not currently dieting to lose weight (Ball, Brown, order to lose weight. The study examines the type of dieting & Crawford, 2002; Blair, Booth, Lewis, & Wainwright, rules that dieters set for themselves, how well dieters adhere 1989; Boutelle, Neumark-Sztainer, Story, & Resnick, 2002; to their self-set dieting rules over the course of their diet, to French et al., 1999; Klesges, Klesges, Haddock, & Eck, which degree their self-set rules are effective for losing 1992; Kruger et al., 2004; Levy & Heaton, 1993; Paeratakul weight, and how the degree of adherence to self-set dieting et al., 2002; Rissanen, Heliovaara, Kneckt, Reunanen, & rules is related to dieting success. We also examine how Aromaa, 1991; Serdula et al., 1999). These studies do not successful a combination of reduced caloric intake and allow inferring which specific dieting strategies are related increased exercise is for losing weight. This combination of to weight loss over the course of a specific dieting episode. strategies is currently recommended by the National A number of prospective studies have examined the Institutes of Health, National Heart, Lung and Blood effectiveness of intervention and commercial weight loss Institute (1998). programs (Bautista-Castano, Molina, Cabrillana, Montoya- Alonso, & Serra-Majem, 2004; Grodstein, Levine, Troy, Spencer, Colditz, & Stampfer, 1996; Riebe et al., 2003; Method Skender et al., 1996; Tsai, Sandretto, & Chung, 2003; Westenhoefer, von Falck, Stellfeldt, & Fintelmann, 2004), Participants but did not study the effectiveness of dieting rules in self- controlled dieting efforts. Other studies compare the Overall, 169 women participated in the study. They were effectiveness of self-set regimens with commercial pro- recruited by flyers posted on a university campus searching for females who were currently on a weight loss diet and grams, but did not assess how more precise strategies used were between the ages of 18–30 years. Of the 169 women by self-dieters predict weight loss success (Heshka et al., recruited, 132 completed both Time 1 (T1) and Time 2 (T2) 2003). measures and were included in the present analyses. These A recent study used a prospective design to examine women were on average 21.45 years old (SDZ2.96, weight loss success of dieting strategies in a sample of 15 range: 18–32) and had a body mass index (BMI) of 23.05 males and 90 females (18–55 years old) who were (SDZ3.66, range: 17.67–41.73). They were 56.8% Cauca- planning to go on a diet (Dean, 2000). Participants were sian, 21.2% Asian, 5.3% African–American, 5.3% Arab, interviewed by phone about the dieting strategies they and 4.5% Latin/Hispanic. The remainder (6.8%) classified planned to use and contacted one month later to assess themselves as ‘other.’ their weight loss and the dieting strategies actually used. It was found that reducing sweets was predictive of Procedure percent of goal weight achieved. Furthermore, reducing ‘other foods and beverages’ and ‘following one’s exercise Ethics approval for the present study was received from routine’ were predictive of weight loss. The author did not the McGill Institutional Review Board. Participants filled report results concerning the relationship between adher- out a questionnaire as part of a larger study. Only questions ence to dieting rules and dieting success, presumably pertinent to the present study are described here. On an because the rules participants used when they began their average of two months later, participants were sent a diet had not been assessed. Furthermore, participants were questionnaire by email to assess dieting success, as presented with a list of strategies that the researcher had described below. The comparably short 2-months follow- compiled, and thus important dieting strategies may have up period was chosen because it minimizes the chances of been missed. any lost weight already being regained in participants who In sum, little is known about the specific rules that are no longer dieting. The data were collected and analyzed dieters use in self-controlled dieting efforts, to which in 2003. extent they adhere to their self-set rules and how the degree of adherence to self-set dieting rules predict Measures dieting success. We therefore conducted a prospective study that uses dieters’ own descriptions of the dieting Dieting rules rules that they intend to follow in their attempt to lose At T1, and again at T2, participants were asked to ‘write weight and assess weight loss achievement after two down up to eight rules you try to follow during your present months in order to establish which types of self-set dieting diet.’ They were provided with examples (e.g. ‘I will not eat rules are most effective. any junk food during my diet.’) and given space for listing B. Kna¨uper et al. / Appetite 44 (2005) 283–288 285 up to eight dieting rules. At T2 they were asked to list up to Adherence to dieting rules eight rules they followed ‘during the past seven days,’ or in case they were no longer dieting, the rules they had followed The extent to which dieters adhered to the rules over the during the last seven days of their diet. course of their diet was examined by comparing the degree to which they reported the same rules at T1 and T2. On Body mass index (BMI) average, dieters were re-interviewed 8.23 weeks Z At T1, participants were asked to report their weight (in (SD 0.37) after the T1 assessment.