Almost 20 percent of men who've tried to lose weight have tried weight-loss supplements, according to a study published in Obesity in April 2008. Although there is limited evidence for some weight-loss supplements, the evidence isn't convincing, notes a review article published in the American Journal of Clinical Nutrition in 2004. Speak with a doctor before taking these supplements, as they can have adverse effects and interact with certain medications.
Caffeine may help with weight loss by increasing metabolism and fat breakdown slightly. Examples of supplements containing caffeine include green coffee bean extract, green tea extract, yerba mate, guarana and kola nut. Doses of more than 400 milligrams per day can cause vomiting, jitteriness, nervousness and abnormal heart rate. The Center for Science in the Public Interest reviewed six studies on caffeine and weight loss and determined that there isn't enough evidence to recommend caffeine-containing supplements, as some studies showed a small positive effect and others showed no effect.
White Kidney Beans
White kidney beans may interfere with carbohydrate absorption and thus increase weight loss somewhat. Potential side effects include flatulence, headache, constipation and soft stools. A review article published in the Nutrition Journal in 2011 found that a substance in white beans may help improve weight loss and limit spikes in blood sugar because of its inhibiting effect on the absorption of carbohydrates.
Pyruvate and CLA
Pyruvate may increase energy expenditure and fat breakdown, but it could also cause gas, diarrhea, bloating and decreases in beneficial high-density lipoprotein levels. A review article published in the Journal of Obesity in 2011 found that pyruvate may help increase weight loss and body fat loss, but larger, longer-term studies are needed to verify this effect.
Conjugated linoleic acid may help promote the breakdown of fat, but it could also cause diarrhea, constipation, upset stomach and abdominal pain. The 2011 Journal of Obesity review article noted that while not all studies showed an increase in weight loss with CLA supplementation, some of those that didn't increase weight loss did increase body fat loss.
Chitosan and Chromium
Chitosan may block the absorption of some dietary fat, but it could also cause constipation, flatulence, indigestion, heartburn, bloating and nausea. While chitosan supplementation didn't decrease fat absorption in women in a study published in the Journal of the American Dietetic Association in January 2005, it did slightly decrease fat absorption in men. The effect was very small, however, amounting to about an extra pound of weight loss every seven months.
Chromium may help limit cravings and hunger so you can eat less, as well as promoting fat loss and increasing muscle. Potential side effects include constipation, nausea, hives, vomiting, watery stools, headache and weakness. The 2004 American Journal of Clinical Nutrition review article noted that chromium picolinate appears to increase weight loss slightly compared to a placebo, but not as much as a mild reduction in calories.
Healthier Weight Loss
Weight-loss supplements on their own won't make a big difference in weight loss. Even the more effective supplements may only help you lose about an extra pound or so a month. If you really want to lose weight and keep it off, you should follow a balanced, reduced-calorie diet and increase your exercise, as this is what the evidence currently supports, according to a study published in Obesity Reviews in February 2015. Get at least 1,200 calories per day, and lose weight at a rate of about 1 to 2 pounds per week. Cut calories by eating fewer foods high in fat, sugar and sodium, instead eating more vegetables, fruits, low-fat dairy products and whole grains.