International Journal of Obesity 2006: 30 ;1389–1396
M Rosell, P Appleby, E Spencer and T Key
It is widely stated that when looking at a snap shot of a population, vegetarians and vegans are leaner than omnivores. Longitudinal data on weight gain in these groups are sparse. A group in Oxford investigated changes in weight and body mass index (BMI) over a 5-year period in meat-eating, fish-eating, vegetarian and vegan men and women in the UK.
Self-reported dietary and lifestyle data were collected at baseline in 1994–1999 and at follow-up in 2000–2003; the average duration of follow-up was 5.3 years.
A total of 21 966 men and women participating in Oxford arm of the European Prospective Investigation into Cancer and Nutrition aged 20–69 years at baseline.
Results:
The mean annual weight gain was 389 g in men and 398 g in women. The differences in weight between meat-eaters, fish-eaters, vegetarians and vegans in age-adjusted mean BMI at follow-up were similar to those seen at baseline. Men and women who changed their diet in one or several steps in the direction meat-eater, fish-eater, vegetarian, vegan showed the smallest mean annual weight gain of 242 and 301 g, respectively.
During 5 years follow-up, the mean annual weight gain in a health-conscious cohort in the UK was approximately 400 g. Only small differences in weight gain were observed between meat-eaters, fish-eaters, vegetarians and vegans. Lowest weight gain was seen among those who, during follow-up, had changed to a diet containing fewer animal foods.
The results suggest that being vegetarian or vegan may not necessarily confer protection against gaining weight and that adjustments in diet and activity are essential.
