Review: Evidence-based Clinical Research of Anti-obesity Supplements in Japan

BACKGROUND The prevalence of obesity has increased dramatically throughout the world, and weight reduction through lifestyle management is urgently warranted. At present, numerous supplements advertised for their anti-overweight property are available in the Japanese market, but most of these lack proper evidence. Thus, we investigated dietary supplements that have been tested in clinical trials. SEARCH STRATEGY We researched anti-obesity supplements in the Japanese market using the google search engine in Japanese with the key terms "anti-obesity supplements," "diet supplements," and "weight reduction supplements." RESULTS We listed 49 companies that supply anti-obesity supplements. Of these, 11 had published clinical evidence of the anti-obesity efficacy of their supplements. These products contain the following active ingredients: Angelica keiskei, bofu-tsusho-san, capsaishin, DHA/EPA, forskohlii, garcinia cambogia, lactoferrin, L-carnitine, oligonol, tea catechin, and yeast hydrolysate. CONCLUSION We obtained 11 supplements for which clinical evidence was published in medical journals in English. We also found 10 products for which clinical or animal evidence was published in Japanese. We expect that many companies will produce evidence of the efficacy of their products in the near future, thereby validating the use of dietary anti-obesity supplements in Japan.