Scientific Opinion of the French Agency for Food, Environmental and Occupational Health & Safety on the establishment of dietary guidelines for people following a diet that excludes some or all foods of animal origin (vegetarians)

Abstract This document presents the opinion of the French Agency for Food, Environmental and Occupational Health & Safety (ANSES), established from the work of its Working Group on Vegetarian diets and validated by its Expert Committee on Human Nutrition. ANSES issued an internal request to establish dietary guidelines for people who follow a diet that excludes some or all foods of animal origin. Firstly, ANSES conducted a systematic review of the scientific literature to identify epidemiological links between health and various types of vegetarian diets. This systematic review showed that the risk of developing type 2 diabetes is lower with vegetarian than with non‐vegetarian diets. With a lower level of evidence, vegetarians are less likely than non‐vegetarians to develop certain diseases, such as ischaemic heart disease, ovulation disorders, certain types of cancer (prostate, stomach, blood) and certain ophthalmological and gastro‐intestinal diseases. However, they are at greater risk of bone fractures and hypospadias (congenital malformation of the urethra). The epidemiological studies examined showed that vegetarians have a less favourable nutritional status in iron, iodine and vitamins B12 and D, and a poorer calcium and phosphorus balance than non‐vegetarians. Vegans also have a less favourable nutritional status in vitamin B2. ANSES then used dietary optimisation to identify combinations of food groups (state variables) enabling the set objectives to be met, i.e. to reduce nutritional and toxicological risks, while deviating as little as possible from current consumption habits. All the nutritional and toxicological constraints and the criteria (minimisations or maximisations) made it possible to take account of the risks associated with nutrient intakes or exposure to contaminants, as well as the expected nutritional benefits. The systematic review and establishment of dietary guidelines using an optimisation tool show that the lacto‐ovo‐vegetarian diet requires particular attention regarding certain nutrients for which requirements in terms of vitamin D and eicosapentaenoic and docosahexaenoic fatty acids may not be met. The risk of requirements not being met by the lacto‐ovo‐vegetarian diet is greater than that associated with the diet of non‐vegetarian populations. In addition, lacto‐ovo‐vegetarians limiting their intake of milk and fresh dairy products may not be able to cover their vitamin B12 requirements. Furthermore, with the vegan diet, which excludes all foods of animal origin, it is difficult to meet the dietary reference value for zinc in men.