Dietary restriction and regression of atherosclerosis.

Rabbits were fed a cholesterol-enriched diet to render them atheromatous. After 3 months on this diet they were switched to a low-lipid stock diet. Some animals were killed at this point, while the rest were divided into (a) a group allowed to eat ad-libitum and (b) a resticted group allowed to eat half by weight of what the ad-libitum group consumed. Most animals were killed at 9 months (i.e. after 6 months' regression). The group allowed the restricted diet showed a 27% weight loss, but their serum cholesterol fell slightly more slowly than that of the ad-libitum animals. Likewise, atherosclerosis was slightly worse in the restricted than in the ad-libitum group. The results do not support the view that severe dietary restriction causes atherosclerosis to regress.