Effect of hydroxycitrate on food intake and body weight regain after a period of restrictive feeding in male rats

We examined whether dietary supplementation of hydroxycitrate (HCA), a comp etitive inhibitor of the extramitochondrial enzyme ATP-citrate-lyase, which inhibits lipogenesis, reduces food intake and body weight regain in rats a fter 10-15% weight loss. In four experiments, 24 male rats were fed restric tively (10 g/day) for 10 days and then given ad lib access to one of four d ifferent diets (HI-Suc high sucrose; HI-Glu=high glucose; Chow=grounded sta ndard rat chow; HI-Glu+Fat=high glucose+fat) varying in the content of fat and low Molecular carbohydrates for the following 10 days. For half of the rats (n = 12), the ad lib diet was supplemented with 3% (w/w) HCA. HCA redu ced body weight regain with all diets except Chow. HCA also reduced food in take temporarily with three of the four tested diets. The suppressive effec t of HCA on food intake was particularly strong with the HI-Glu + Fat diet (fat=24% of energy). With Diet HI-Glu and Hi-Glu + Fat HCA reduced the feed conversion efficiency (cumulative body weight regain (g)/cumulative food i ntake (MJ)) during the 10 ad lib days, suggesting that it also increased en ergy expenditure. This effect seemed to be positively related to the glucos e content of the diet. All in all, HCA reduced body weight regain after sub stantial body weight loss, and the effects are presumably linked to its inh ibiting effect on lipogenesis, but the exact mechanism still has to be dete rmined. (C) 2001 Elsevier Science Inc. All rights reserved.