Vegetarians of three types were studied in Greater London: thirty-four meat-avoiders, fifty-two lacto-ovo-vegetarians, and thirty-eight vegans. Weighed dietary intake measures were made over 3 d. Cereals were the mainstay of the diet, supplemented by dairy products (demi-vegetarians and lacto-ovo-vegetarians), vegetables and fruit, and soya-bean products (vegans). Many vegans progressed by stages to complete avoidance of animal foods; some had retreated, but most were highly committed. Demi-vegetarians were the least involved in a 'vegetarian lifestyle'. All groups had mean energy intakes close to the current dietary reference values (DRV), with adequate protein intakes. Only vegans had fat intakes close to current recommendations; all groups had high dietary polyunsaturated:saturated fatty acid ratios. Mean intakes of all micronutrients studied for demi- and lacto-ovo-vegetarians met the UK DRV. Intakes of iodine, riboflavin, and vitamin B12 for vegans were below DRV; more than half considered their diets supplied all necessary vitamins. About 25% took some type of dietary supplement during the survey. The impact of low I intakes should be further studied, and it is recommended that 'new' vegetarians and vegans should use appropriate dietary supplements.