The effect of dietary fat on weight loss, body composition and adipose tissue lipoprotein lipase activity (ATLPL) was studied during a 10 week food restriction assay in rats fed fat restricted (R) diets (12%, 28%, 45%) to equal 75% of their previous energy intake and compared to control rats. The 45% R group showed less body weight loss and reduction of adiposity compared with the 12% R group as well as a higher ATLPL activity compared to the control rats.