The food intake and nutritional status were assessed before, during and after radiotherapy in 143 women with gynaecological malignancies randomized to either a low fat, low lactose diet or a normal diet during treatment. The patients on the low fat, low lactose diet had an intake of fat of 34 g per day during radiotherapy, 41 g per day 6 weeks after radiotherapy and 52 g per day 1 year after radiotherapy, when they were no longer on the diet. The intake in the control group was 57 g per day, 67 g per day and 66 g per day respectively. The total energy intake was reduced in both groups during radiotherapy. The reduced intake of energy resulted in weight loss, greatest in the intervention group. 1 year after radiotherapy both groups had almost regained their initial weight. No marked changes were observed in nutritional status as a result of decreased nutritional intake during radiotherapy.