You're right to be skeptical. Chromium picolinate won't help with weight loss, won't help build muscles (as some promoters claim), and won't reduce your cravings or increase your metabolic rate. And there's no proof that it will lower cholesterol, another popular claim.
While it won't help us lose weight, we do need trace amounts of the mineral chromium. It plays a key role in processing carbohydrates and fats and helps with regulation of blood sugar by working with insulin to help transport glucose into cells. Natural food sources include whole grains, bran cereals, seafood, green beans, broccoli, prunes, nuts, peanut butter and potatoes.
I do recommend supplements of GTF (glucose tolerance factor) chromium, a form that is well used by the body, to people with type 2 diabetes and to those with metabolic syndrome, which is marked by insulin resistance. This recommendation includes many people, including those who gain abdominal fat easily.
The dose is 1,000 mcg per day. Supplemental GTF chromium may help prevent further weight gain and improve body composition in people with metabolic syndrome when combined with a healthy program of diet and physical activity.
At the moment, five separate clinical trials are recruiting patients to test chromium's effects on diabetes, insulin resistance and glucose tolerance. Chromium supplements have also been studied for their effects on cholesterol levels, but results have been inconsistent. In some of the studies researchers didn't control for the dietary factors that influence cholesterol levels. Of 24 studies that looked at the effects of chromium picolinate supplementation on weight changes, none found any significant effect. Some of these studies were not of high quality, but there is still no reason to believe that taking chromium will promote weight loss.
The only research I've seen that suggests that chromium might ease cravings is a small study at Weill Medical College of Cornell University in New York. Researchers found that chromium picolinate helped reduce cravings among patients with atypical depression, a form of the disorder that may involve overeating, weight gain, excessive sleeping and a feeling of heaviness in the arms and legs. After taking the supplement, a subgroup of the patients who reported “irrepressible” cravings for sweets and starches showed an improvement in managing hunger, carbohydrate craving and mood changes. More studies are needed to see whether these findings apply to other depressed patients who tend to overeat. The study was published in the September 2005 issue of the Journal of Psychiatric Practice.
Andrew Weil, M.D.