Weight changes in 303 women participating in a low-fat dietetic trial were studied over 2 years. Women were randomly allocated to a group receiving intensive instructions on low-fat diet or to a control group. 1 year afterwards, women from the intervention group showed a higher decrease in fat intake and weight compared to control women. Univariate and multivariate analyses shows that weight loss is more associated with changes in energy percentage coming from fat that with total energy intake, which suggests that adiposity depends both on energy balance and proportion of energy coming from fat.