Effect of changing to a self-selected vegetarian diet on anthropometric measurements in UK adults

Abstract

Background: Vegetarians are often a little leaner compared with nonvegetarians and suffer less from obesity and its associated complications than nonvegetarians. Whether this is because of not eating meat specifically is unclear.

Objective: We investigated whether changing to a self-selected vegetarian diet resulted in changes to anthropometric measurements. Design Subjects (n = 33; seven males and 26 females) who were in the earliest stages of becoming vegetarian were observed for 6 months. Data on dietary intake, using a 3-day estimated dietary diary, and body composition were obtained at baseline and after 6 months of following a self-selected vegetarian diet.

Results: Dietary calculations showed that on changing to a self-selected vegetarian diet, there was a significant reduction (P < 0.05) in energy intake (8.9 MJ day(-1) versus 8.1 MJ day(-1)), and in the proportion of energy from saturated fatty acids (12.9% versus 11.3%) and a significant increase (P < 0.05) in the proportion of energy from carbohydrates (44.9% versus 47.5%) and in intake of nonstarch polysaccharides (NSP) (1.6 g MJ(-1) versus 2.0 g MJ(-1)). Significant reductions in mid-upper arm circumference, calculated body fat, biceps and triceps skinfolds and waist and hip circumferences were observed. No reduction in body weight was observed.

Conclusion: The findings of our study suggest that significant dietary changes, helping people to conform more closely to current dietary recommendations, occurred when people became vegetarian. In this study we did not find any significant change in body weight, but significant reductions were observed in skinfold thickness and waist : height ratio which imply that on changing to a self-selected vegetarian diet, the subjects became leaner.