Diet and Growth in Young Vegetarians

Marijke van Dusseldorp,* Pieter C. Dagnelie,** and Wija A. van Staveren*

*Department of Human Nutrition, Agricultural University, Wageningen, The Netherlands; **Institute of Internal Medicine II, Erasmus University, Rotterdam, The Netherlands

The popularity of vegetarianism has increased greatly over the past few years because of concern about the environment, animal welfare, and healthy eating. From a historical point of view, the pursuit of vegetarianism for reasons of physical health is a recent phenomenon. Before the nineteenth century, a diet without animal food either represented a habit justified by moral and metaphysical arguments or was due to poverty in areas where animal food was hardly available. Only as nutritional sci- ence expanded from the mid-twentieth century onward did vegetarianism acquire general recognition as a healthful diet (1-3). Although these diets offer advantages to the health of adults because of their low saturated fat and high fiber content, the adequacy of strict vegetarian diets in children has been questioned. For instance, the adoption of such diets for young children has been associated with stunting (4), and the adoption by female teenagers was associated with disorders of menstruation (5). When diets with no animal foods are used, the risk of nutrient deficiency is greatest during periods of physiologic stress and accelerated growth. Such diets may contain inadequate amounts of some nutrients, e.g., vitamin B12, vitamin D, iodine, taurine, and some long-chain polyunsaturated fatty acids such as eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3). Furthermore, plant foods contain components that may decrease the absorption of several minerals, such as iron, zinc, and calcium. These components occur in higher concentration in unrefined plant foods, which are favored by many vegetarians and which they also feed to their children. This may lead to iron deficiency anemia and rickets. In 1982, we conducted a study on the effects on height and weight of vegetarian diets practiced by an ecological, anthroposophic, and macrobiotic group of Dutch preschool children. The study showed that the ecological and anthroposophic groups of children were fed lacto-ovo-vegetarian diets and were somewhat lighter and shorter than a control group fed an omnivorous diet (6). The lacto-ovo-vegetarian diets con- formed better to the Dutch recommended dietary allowances (RDAs) (7) than the omnivorous and macrobiotic diets. This conforms to other and more recent findings (3,8). In contrast, height and weight of the children fed macrobiotic diets were signifi- 209 210 DIET AND GROWTH IN YOUNG VEGETARIANS cantly less than in the control group. Children fed the macrobiotic diet had a very restricted, almost vegan type of diet, consisting of grain cereals (mainly rice), vegetables, and pulses with small additions of seaweeds, fermented foods, nuts, seeds, and seasonal fruits, and some fish. Intakes of calcium, riboflavin, and vitamin D recorded for children on the macrobiotic diet were substantially below the Dutch RDAs. To determine at what age growth in children on macrobiotic diets slows down, and if any return to the norm occurs later in childhood, an anthropometric study was performed in the Dutch macrobiotic child population aged 0-8 years (n = 243) (9). Anthropometric measurements included weight, height, mid-upper arm circumfer- ence, and triceps and subscapular skinfolds. The results showed that the age curves followed the median of the standard (10,11) until the age of 6 months, after which a marked decline was observed, reaching a minimum level (10th centile) between 1.5 and 2 years. After the age of 2 years, the anthropometric data showed only a partial return to the 50th centile. In close collaboration with macrobiotic teachers, dietary recommendations were formulated and sent in a brochure to the parents. The guidelines included the following: 1. The addition of fat in meals as an additional source of energy. 2. The inclusion of 100-150 g of fatty fish as an extra supply of vitamins B12 andD. 3. Addition of at least one serving of dairy products in the diet as a source of calcium, vitamin B2, and protein. For followers of the macrobiotic diets, this was the most difficult recommendation to adopt. The present chapter will discuss results of a follow-up study conducted 2 years after the first cross-sectional study and 6 months after the parents had received the instructional brochure. In addition, data on a subgroup of children contacted again in 1993 will be reported. Parts of the follow-up study and an in-depth mixed longitudinal study on diet and growth during the weaning period in children on macrobiotic diets have been published earlier (12-15).

CHANGES IN DIET AND GROWTH IN CHILDREN AGED 2-9 YEARS ON MACROBIOTIC DIETS

Subjects

One hundred and ninety-four children (98 boys and 96 girls) participated in the study. This is 80% of the original population. Nonresponse was due to refusals (4%), removals (1%), children younger than 2 years (1%), children no longer fed a macrobiotic diet (12%), and not all measures being completed (6%).

Methods

For an extensive description of the methods, see Dagnelie et al. (9). DIET AND GROWTH IN YOUNG VEGETARIANS 211

Anthropometry

Body weight was measured using a SECA 707 electronic scale with the child wear- ing light clothing. Standing height was measured with a flexible steel tape, which was attached to a metal bottom and top board. The measurements were performed by four trained observers. Quality control with a reference observer showed an over- estimation in height of 0.4 cm (p < 0.001).

Reference Values

Data from The Netherlands third nationwide survey (1980) were used as a reference (10).

Questionnaire

Food habits of the participants were checked by a structured questionnaire, which was filled in by a parent, usually the mother. It was the same questionnaire that was used in the baseline study, with some extra questions about foods recommended in the brochure. The food questionnaire is a frequency list (a 6-point scale ranging from "never" to "daily") of foods typical or atypical for the macrobiotic diet. Questions were also asked about changes in dietary pattern.

Data Analysis

In order to make the data on anthropometric development independent of the children's age and sex, standard deviation (SD) scores were calculated from the median (P50) and standard deviation of the reference data as follows: SD score (a) = (a - median of reference)/(SD of reference) For this purpose, the P50 and the SD of the reference were interpolated to each child's exact age. To correct for a skewed distribution of the reference data of body weight for girls from 4 years onward, the observed weight and the reference data for this group were first transformed to achieve normal distribution by means of the equation: X = log (weight - 3.663 x age + 14.758) From the results of the baseline study in 1985, children were classified in three age groups: (a) a 2-year-old group, because some of the children in this age group will still be breast-feeding; (b) a 3-5 years group, because catch-up growth was expected in this age category; (c) 6 years and older, because it was expected that from 6 years onward growth would follow a reference growth percentile. Student's t test was used to test for significant differences or changes. 212 DIET AND GROWTH IN YOUNG VEGETARIANS

SOS score weight o

-0.5 -

-1.5 -

FIG. 1. Standard deviation scores (SDS) of weight for age of macrobiotically fed children in 1985 (n = 243) and 1987 (n = 194). (Reproduced from T Soc Gezondheidszorg, 1992; 70: 227-33, with permission.) Results

Anthropometry

Figures 1 and 2 show a cross-sectional comparison of SD scores by sex for weight and height. Although there was a tendency to less negative scores in 1987, none of the differences was statistically significant.

SDS score height o

-0.5 -

-1.5 -

FIG. 2. Standard deviation scores (SDS) of height for age of macrobiotically fed children in 1985 (n = 243) and 1987 (n = 194). (Reproduced from T Soc Gezondheidszorg, 1992; 70: 227-33, with permission.) DIET AND GROWTH IN YOUNG VEGETARIANS 213

TABLE 1. Change in standard deviation score per year of macrobiotic children in different age groups

Change in SDS per year (mean ± SD) Current age (1987) 2 y 3-5 y 6-9 y

Boys (n =•• 25) (n = 40) (n = 33) Weight -0.17 :t 0.11 0.14 ± 0.05* -0.01 d: 0.02 Height -0.44 :t 0.09" 0.09 ± 0.04*" 0.04 i: 0.04 Girls (n =-• 18) (n = 48) (n = 30) Weight -0.15 ± 0.12 0.16 ± 0.05* 0.08 d: 0.06 Height -0.55 :t 0.11* 0.14 ± 0.04* 0.11 ± 0.03*

From Smeets ef al. (12). SDS, standard deviation score. * p <0.01; "p < 0.001; *"p < 0.05 (paired f test)

Growth velocity, expressed as change in SD score of the macrobiotically fed children in various age groups, is presented in Table 1. A marked growth depression for height was observed in the children who at the time of follow-up were 2 years old. For children aged 3-5 years, a slight but significant positive change had occurred for both weight and height. In children aged 6-9 years, no changes in SD score occurred except for a slight but significant positive trend toward the 50th centile for height in girls.

Diet

Few changes were found in the frequency of consumption of foods typical of the macrobiotic diet, but there were some changes in the consumption of animal products, especially dairy products and fish, as well as vegetables and vitamin D supplements.

Relation of Diet and Growth

In those children whose consumption of fish and dairy products had increased since 1985, linear growth was significantly faster (p < 0.05) than in the other macrobiotic children.

THE 1993 FOLLOW-UP STUDY

In 1993, the measurements on anthropometry and food habits were repeated in 228 children who had participated in one or more of the former studies. Questions about food frequency were answered by the child with the help of the parent (usually the mother). Since 1987, many families have made modifications to the macrobiotic diet, and in particular the consumption of dairy products has increased. The data from the 1993 follow-up study show, on a group level, significant linear catch-up 214 DIET AND GROWTH IN YOUNG VEGETARIANS

TABLE 2. Data on growth in height and weight and consumption frequency of animal products of five boys and five girls reported to have followed a strict macrobiotic diet from birth to 1993

1985 1987 1993

Age 2.3 (0.4,6.4) 4.2 (2.3,8.4) 10.1 (8.2,14.3) Mean standard deviation scores (range) Height/age -0.8 (-2.7,1.3) -1.1 (-2.8,0.4) -0.3 (-1.5,0.5) Weight/height -0.2 (-1.3,0.8) 0.4 (-1.2,2.2) 0.1 (-0.8,1.2) Mean consumption frequency (range)8 Dairy products 1.1 (1,2) 1.0(1,1) 1.6(1,2) Meat 1.1 (1,2) 1.0 (1,1) 1.2(1,2) Fish 1.7(1,4) 3.4(1,5) 3.0 (1,4) Egg 1.7(1,3) 1.4(1,3) 2.7(1,4)

• 1, never; 2, seldom; 3, 1-3/mo; 4, 1-2/w; 5, > 3/w; 6, daily. growth (16). However, the fact that between 1987 and 1993, almost all families had changed their diet toward a more lacto-ovo-vegetarian or omnivorous type makes it difficult to analyze the influence of nutrition on growth. We could identify only five boys and five girls who still followed a rather strict macrobiotic diet in 1993 (i.e., consumption of dairy products and meat was "never" or "seldom"). Of these 10 children, 7 were 0, 1, or 2 years old at the start of the study in 1985. The data on growth in height and weight and on consumption of animal products of this subgroup of 10 children are presented in Table 2. Since results were similar for boys and girls, no sex-specific data are given in the table. The mean linear growth curve of boys and girls are represented by the filled squares in Figs. 3 and 4.

height (cm)

188

168

148

128

108

48 l, 8 III 12 14 age (years}

FIG. 3. Mean linear growth curve of a subgroup of five boys (•) and the individual growth curve of one of these boys (T). All boys reported to have followed a strict macrobiotic diet from birth onward.—10th, 50th, and 90th centiles of Dutch reference population (10). DIET AND GROWTH IN YOUNG VEGETARIANS 215

height (cm)

168

148

128

108

4X 0 1 6 7 8 9 10 11 12 13 14

age (years)

FIG. 4. Mean linear growth curve of a subgroup of five girls (•) and the individual growth curve of one of these girls (T). All girls reported to have followed a strict macrobiotic diet from birth onward.— , 10th, 50th, and 90th centiles of Dutch reference population (10).

Weight-for-height followed the median of the Dutch reference standard. Height- for-age was almost 1 SD below the median in 1985, when the children were on average 2 years old. In 1987, the consumption of fish increased slightly but no catch-up in linear growth occurred. Linear catch-up growth occurred between 1987 and 1993, although the consumption of dairy products, meat, and eggs was only slightly higher than in 1985 and 1987. As an illustration of the individual variation in nutritional needs, the linear growth of one boy showing strong catch-up growth after 1987 and one girl showing normal growth throughout the study are also presented in Figs. 3 and 4 (indicated by filled inverted triangles). The boy never consumed meat or dairy products. Eggs were consumed one to three times per month and fish once or twice per week during all periods. Until 1987, the girl never consumed animal products and did so only seldomly after 1987.

DISCUSSION

The results of the studies on growth of children fed macrobiotic diets, which are very strict vegetarian diets, show that linear growth faltering occurred between the age of 6 months and 2 years. During this period of accelerated growth, the macrobiotic diet was nutritionally inadequate for optimal linear growth. The follow-up study in 1987 showed positive effects on linear growth of increased consumption of dairy products and fish. So consumption of animal products seems important for linear growth, but from our follow-up studies we have no data on the amounts of food or nutrients consumed. When the children were measured again in 1993, it appeared that a subgroup of children who reported continued adherence to the macrobiotic diet 216 DIET AND GROWTH IN YOUNG VEGETARIANS also showed linear catch-up growth, although the consumption of animal products remained low. Height-for-age is seen as a good indicator of the adequacy of the diet in the past, and catch-up growth occurs when adequate nutrition is reinstituted after a period of malnutrition (17). Thus the observed catch-up growth indicates that before 1985 or 1987, the diet was nutritionally inadequate. Of course, linear growth is strongly deter- mined by genetic factors, but the fact that catch-up growth occurred indicates that the low height of macrobiotic-fed children in 1985 and 1987 cannot fully be explained by genetic factors. One explanation for the observed catch-up growth might be that even a very small increase in consumption of animal products has been sufficient for these children to establish catch-up growth. Several studies have suggested an effect of animal food on linear growth, but it is unclear as to which nutrients are responsible for this effect. The limiting factor could be, for example, amino acids, zinc, or total fat (18); there is little information on the specific role of protein in linear growth (19). Another possible reason for the observed catch-up growth in the strict macrobiotic subgroup in 1993 might be the fact that when children get older, they become less vulnerable to nutritional deficiencies. On average, the children were now 10 years of age. Their total energy intake is much higher compared to younger age groups, which lowers the risk of nutritional deficiencies. Furthermore, it is possible that the reported intake of animal products does not reflect the true intake of the children. In the presence of the parents, children might underreport the consumption of nonmacrobiotic food products that they may consume at school or with friends. Probably the most important point to stress here is the fact that the subgroup of strictly macrobiotic children is not representative of the whole macrobiotic population that was studied in 1985 and 1987. In 1987, there were subjects who reported a higher consumption of animal products but who nevertheless had a lower height for age (SD score < 2) than the subgroup reported here. So the fact that in 1993, these 10 subjects still adhered to a restricted diet, whereas the majority of the population did not, might be correlated with the fact that they were doing better on a strict diet than the population as a whole. Thus, they might represent individuals situated at the left end of the Gaussian distribution curve of nutritional needs. In other words, what might have been sufficient for these children could be insufficient for the vast majority of the population. During puberty, children have a great potential for catch-up growth (20). In 1993, the height for age of macrobiotic children was still below the median of the Dutch reference. At this time, most of the children had not yet entered puberty. It will be of interest to follow the growth and development of these children and measure them again after puberty to see whether full catch-up in height occurs.

CONCLUSIONS

Young children below 2 years of age constitute a high-risk group for growth retardation when following a macrobiotic diet, which is a vegan type of diet. We have some DIET AND GROWTH IN YOUNG VEGETARIANS 217 indications that additional consumption of animal foods is related to accelerated linear growth. However, between 4 and 10 years of age, linear catch-up growth also occurred in children who were on a strictly macrobiotic diet. Assuming that the reported dietary information was not biased by the presence of the parent, this indicates that, at least for some subjects, only very small amounts of animal products might be sufficient for linear growth above 4 years of age or so. However, since the subgroup presented here is not representative of the macrobiotic population, it might be that most children will require more animal products for optimal growth. The macrobiotic diet has characteristics similar to the diet of many children in developing countries. In such countries, however, this diet coincides with problems such as infection and poverty, which also influence linear growth. By studying a group of macrobiotic children in The Netherlands, we were able to study the effects of nutrition alone on growth.

REFERENCES

1. Whorton JC. Historical development of vegetarianism. Am J Clin Nutr 1994; 59: 11O3-9S. 2. Sanders TAB, Reddy S. Vegetarian diets and children. Am J Clin Nutr 1994; 59: 1176-81S. 3. Dwyer JT. Health aspects of vegetarian diets. Am J Clin Nutr 1988; 48: 712-38. 4. Dagnelie PC, Staveren WA van, Hautvast JGAJ. Stunting and nutrient deficiencies in children on alternative diets. Ada Paediatr Scand 1991; 374(suppl): 111-8. 5. Bringer J, Hedar B, Giner B, Richard JL, Jaffiol C. The influence on female fertility of abnormal body weight and unbalanced diets. Presse Med 1990; 19: 1456-9. (In French.) 6. Staveren WA van, Dhuyvetter JHM, Bons A, Zeelen M, Hautvast JGAJ. Food consumption and height/weight status of Dutch preschool children on alternative diets. J Am Diet Assoc 1985; 85: 1579-84. 7. Netherlands Nutrition Council. Nederlandse voedingsnormen 1989,2nd ed. The Hague: Voorlichting- sbureau voor de Voeding, 1991. 8. Tayter M, Stanek KL. Anthropometric and dietary assessment of omnivore and lacto-ovo-vegetarian children. J Am Diet Assoc 1989; 89: 1661-3. 9. Dagnelie PC, Staveren WA van, Klaveren JD van, Burema J. Do children on macrobiotic diets show catch-up growth? A population-based cross-sectional study in children aged 0-8 years. Eur J Clin Nutr 1988; 42: 1007-16. 10. Roede MJ, Wieringen JC van. Growth diagrams 1980; Netherlands third nation-wide survey. Tijdschr Sociale Gezondheidszorg 1985; 63 (suppl): 1-34. 11. Tanner JM, Whitehouse RH. Revised standards for triceps and subscapular skinfolds in British children. Arch Dis Child 1975; 50: 142-5. 12. Smeets FWM, Dagnelie PC, Staveren WA van, Kuik MJJA van, Matze M, Schlatmann AM. Imple- mentation of nutrition recommendations by macrobiotic families in The Netherlands and growth of macrobiotic children until 9 years of age. Tijdschr Sociale Gezondheidszorg 1992; 70: 227-33. 13. Dagnelie PC, Staveren WA van, Verschuren SAJM, Hautvast JGAJ. Nutritional status of infants aged 4 to 18 months on macrobiotic diets and matched omnivorous control infants: a population- based mixed longitudinal study. I. Weaning pattern, energy and nutrient intake. EurJ Clin Nutr 1989; 43: 311-23. 14. Dagnelie PC, Staveren WA van, Vergote FJVRA, Burema J, Hof MA van't, Klaveren JD van, et al. Nutritional status of infants aged 4 to 18 months on macrobiotic diets and matched omnivorous control infants: a population-based mixed-longitudinal study. II. Growth and psychomotor development. EurJ Clin Nutr 1989; 43: 325-38. 15. Dagnelie PC, Dusseldorp M van, Staveren WA van, Hautvast JGAJ. Effects of macrobiotic diets on linear growth in infants and children until lOyesasof age. EurJ Clin Nutr 1994; 48 (suppl 1): S103-12. 16. Dusseldorp M van, Arts ICW, Bergsma JS, Jong N de, Staveren WA van. Effects of macrobiotic diets on linear growth in children [abstr]. 2nd International Congress of Nutrition in Pediatrics, March 16-19, 1994, Lisbon, Portugal. 218 DIET AND GROWTH IN YOUNG VEGETARIANS

17. Ashworth A, Millward DJ. Catch-up growth in children. Nutr Rev 1986; 44: 157-63. 18. Waterlow JC. Summary of causes and mechanisms of linear growth retardation. Eur J Clin Nutr 1994; 48(suppl 1): S210. 19. Allen LH. Nutritional influences on linear growth: a general review. Eur J Clin Nutr 1994; 48(suppl 1): S75-89. 20. Kulin HE, Bwibo N, Mutie D, Santner SJ. The effect of chronic childhood malnutrition on pubertal growth and development. Am J Clin Nutr 1982; 36: 527-36.

DISCUSSION

Dr. Haschke: Your data indicate that in terms of anthropometry, macrobiotic diets have no long-term effects on growth. How do your data fit with the observations from Dwyer in southern California (1)? This group also followed a cohort of macrobiotic children and vegetarian children at least up to the age of 6 or 7. In your data, the distribution of weight and height seems completely normal, which I find surprising. Dr. Van Staveren: I have to speculate to some extent that there is no effect of the macrobiotic diet on the long-term growth. We would have to study this group again after they have gone through puberty (up to now most of the children we have studied have not reached puberty). Although the weight-for-height is normal, if you look at height-for-age, you can see that the median is not yet reached. The differences between our cohort and the one of Johana Dwyer was that Dwyer saw catch-up growth which we did not see in our first studies. Dr. Haschke: In your previous publication (2,3), you described a lot of biochemical nutritional deficiency states, among them poor vitamin B12 status. Have you any data on long- term outcome of neurophysiologic development or is this under investigation? Dr. Van Staveren: We would be very interested in studying the biochemical status and neurophysiologic development of macrobiotic children but to now we have been unable to obtain a grant to do this rather expensive study. The first thing we will do is to examine their bone mass to see if a low calcium intake at an early age has an effect on these children at 10-14 years of age. Dr. Hernandez: Have you any longitudinal data for growth velocity? It is difficult to assess catch-up growth without velocity data. Dr. Van Staveren: Yes, we do have data on the velocity; those are the data on which we concluded there was accelerated growth. Dr. Guesry: I was interested by your study showing the catch-up growth obtained by providing supplemental animal protein. As you know, Waterlow theorized that stunting was mainly due to protein deficiency, and there was a very interesting discussion between him and Royer, who died recently, who was of the opinion that all of these studies were biased because the animal protein supplement was mainly milk-based and was providing a lot of calcium. Was your animal protein supplement milk or was it something else, and are you able to make the distinction between the effect of protein and of calcium? And since the main difference between animal protein and vegetable protein is a few amino acids, mainly lysine, do you know if anybody has used this type of population to make the simple but important experiment of complementing the diet with small quantities of selected amino acids to see if this is really the cause for the stunting? Dr. Van Staveren: We are able to distinguish between the different sources of animal protein. Children who were mainly introducing fish and dairy products had more accelerated growth than those who were introducing some milk, but that was a very small group. It is DIET AND GROWTH IN YOUNG VEGETARIANS 219 hard to extrapolate that result to a larger group of children. As to the other question, I don't know of any study with extra amino acids. Dr. Whitehead: There can be no doubt of the tremendous importance of the data that we have just seen, especially to those of us who have a primary interest in developing countries, because here we have a group of European children living in a healthy country under hygienic conditions, but they show similar patterns of growth to those that Dr Gracey has shown us for much less privileged people, i.e., relatively good growth over the first 6 months, then a definite fall-off. If there is any subsequent catch-up, it is exceedingly slow. I wonder whether there might be some important biological principle involved here; why do the children ulti- mately not start to grow more quickly? The other thing that came to my mind is your nutrient data. The biggest difference with the macrobiotic group was their calcium intake, which was about half that of the other groups, much more reduced than protein. Riboflavin was also reduced, though exactly where that would fit in I don't know. I think your data point a finger at calcium, and we should not be too surprised that calcium is important because it is a building brick for length. How can children be expected to grow at an optimal rate if the building bricks are absent? Dr. Van Staveren: It is very hard to find out which nutrients are most involved. We saw very slow catch-up growth, but in contrast to a clinic situation, we saw the children only in 1987 and again in 1993, so we don't know what happened in between. The calcium intake was very low, but in a study I did in Surinam, where they also don't have much of dairy products and where their calcium intake is also very low, we didn't see any effect on bone mass. However, there may be genetic differences in calcium requirements. Dr. Bonjour: I don't think that the effect on growth is likely to be due to lack of substrate. I think what we have to consider is the possibility that calcium could influence the production of growth factor in the osteoblastic cells. There is some evidence in vitro for this direct effect and in animal experiments that we carried out a long time ago, there was a direct effect of the calcemia on growth when we controlled for everything else in the diet. Dr. Van Staveren: Do you also think that dietary vitamin D deficiency in combination with calcium deficiency might have had an effect on height? Dr. Bonjour: As you know, the main source of vitamin D is the skin and I presume that your children go to the sun and they will probably acquire sufficient reserves of vitamin D during the summertime. Dr. Van Staveren: In The Netherlands, we have sun but in these infants we have seen evidence of rickets. Dr. Giovannini: The fiber intake is very high. Do you think it was too high? Dr. Van Staveren: We believe that the high fiber intake, especially in children younger than 2 years, might be a problem. One indication of this was that, although these young macrobiotic children had a high iron intake because they ate whole-grain products, their iron status indicated iron deficiency. So there is an indication that mineral absorption is impaired and this might be due to the fiber. Dr. Whitehead: As a follow-up to Dr. Bonjour's comment, it is possible of course to work out the calcium accretion rate in a child growing along the 50th centile, and with the sort of intakes that we were hearing about, the percentage absorption would have to be quite high. It is difficult to believe, bearing in mind the point that Dr. Giovannini has just made about the high fiber and high phytate content of this diet, that the percentage absorption would be as high as is necessary to achieve a normal accretion rate. My guess is that if you measured urinary calcium excretion, you would have found it to be very low. 220 DIET AND GROWTH IN YOUNG VEGETARIANS

Dr. Ballabriga: Did the diet you used include one of the so-called organic foods? Generally organically grown foods have been grown in soil enriched with organic fertilizers rather than with chemical or synthetic fertilizers and pesticides. I ask this because in groups receiving organic foods, such as organic apple juice, there is a risk of the presence of strange substances produced by molds, like patulin for instance. Have you had any trouble with that? Dr. Van Staveren: The macrobiotic and ecological groups used what we call organically grown foods. We haven't seen any trouble with molds, but I think hygienic circumstances in these houses were very good. They cleaned their vegetables and they were cooked, in contrast to some other alternative diets. Dr. Lentze: You stated that you reinvestigated this group of children; they had changed their diet to a more lacto-ovo-vegetarian diet. I wonder how this change occurred; was it due to the parents or was it by self-selection? What was the reason for the change? Dr. Van Staveren: We did a lot on nutrition education and at the end of the study, we made nutrition guidelines. When we finally came up with all of the results, the parents recognized the nutritional problems in their children and many of them were happy to change to another diet. So it was mainly the parents' choice. Also most of the children were below 12 years of age, so they don't choose their diets themselves; they are dependent on what is served at home. Dr. Gruskin: The implication of your study is that growing more or growing taller is better. Is this necessarily so? What is the difference between what a child's ideal height should be versus what the human race can maximally achieve? If we look over the last few centuries, the human race has grown taller but this has not necessarily made it better, unless you play professional basketball. Certainly the Aborigines are shorter, and when they are exposed to Western society, they grow taller. However, when they have kidney failure as a child, they appear to develop renal insufficiency sooner if they are taller! Dr. Van Staveren: There were many aspects of the diet apart from its effect on growth that suggested it was not healthy. We saw evidence of clinical deficiencies, with unsatisfactory hematologic indices and low vitamin B12 levels as well. That was the main reason why we thought these children should have a more varied diet. But I agree with you, it is a big question as to what is the ideal type of growth.

REFERENCES

1. Dwyer JT, Dietz WH Jr, Andrews EM, Suskind RM. Nutritional status of vegetarian children. Am J Clin Nutr 1982; 35: 204-16. 2. Dagnelie PC, Vergote FJVRA, Staveren WA van, Berg H van den, Dingjan PG, Hautvast JGAJ. High prevalence of rickets in infants on macrobiotic diets. Am J Clin Nutr 1990; 5: 202-8. 3. Dagnelie PC, Staveren WA van, Vergote FJVRA, Dingjan PG, Berg H van den, Hautvast JGAJ. Increased risk of vitamin B-12 and iron deficiency in infants on macrobiotic diets. Am J Clin Nutr 1989; 50: 818-24.