Hydroxycitric Acid (HCA) – Good for Weight Control?
Preliminary studies in animals suggest that HCA may be a useful weight-loss aid. HCA has been demonstrated in the laboratory (but not yet in clinical trials with people) to reduce the conversion of carbohydrates into stored fat by inhibiting certain enzyme processes. Animal research indicates that HCA suppresses appetite and induces weight loss.
Hydroxycitric Acid (HCA) – Human Weight Loss Trials
A double-blind trial that provided either 1,500 mg of HCA or a placebo per day to 135 overweight men and women, who also were on a calorie-restricted diet, found after 12 weeks that the HCA supplementation did not produce a significant change in weight loss.
Hydroxycitric Acid (HCA) – Unproven for Human Weight Loss Trials
Uncontrolled and/or preliminary evidence from several other human trials suggests the possibility that weight loss might occur; however, none of these studies is as methodologically strong as the negative trial previously mentioned. These less-rigorous studies used a similar calorie-restricted diet and a similar amount of HCA as the negative trial. However, the double-blind study used a high-fiber diet not used in the prior studies. It has been suggested that such a diet might limit absorption of HCA. Future studies that measure blood levels of HCA (to check whether or not the supplement was absorbed) are necessary to resolve this issue. At the present time, the effectiveness of HCA for weight loss remains unclear and unproven.
Hydroxycitric Acid (HCA) – Weight Loss Dosage
Optimal amounts of HCA remain unknown. Although dieters sometimes take 500 mg of HCA three times per day (before each meal), this amount is far below the levels used in animal research (figured on a per-pound body weight basis). The effect of HCA is enhanced when used in conjunction with a low-fat diet, because HCA does nothing to reduce the caloric effects of dietary fat. Since HCA’s mechanism of action seems to be at least partially a blockade of conversion of simple sugars into fats, it is likely to work best in conjunction with a high simple sugar diet. HCA may therefore be less useful if it only offsets the negative effects of an otherwise unhealthy diet. High-fiber diets may impair absorption of HCA as noted above. HCA supplements are available in many forms, including tablets, capsules, powders, snack bars, and chewing gum.