Accumulating data suggest that food supplementation with seaweeds which traditionally are an important part of food culture in South-East Asian countries might lead to essential health benefits. In this short review, we summarize findings from experimental studies on the effects of fucoxanthin (a carotenoid derived from brown seaweeds) on lipid metabolism, adiposity, and related conditions and discuss the possible underlying mechanisms.Supplementation of fucoxanthin or its derivatives consistently attenuated body and visceral fat weight gain, lipid accumulation in the liver, decreases insulin resistance, and improves the plasma lipid profile in rodents fed a high-fat diet. It should however be noted that in diabetic/obese KK-Ay mice with genetically compromised insulin signaling, fucoxanthin might increase the plasma levels of cholesterol and low-density lipoproteins. The anti-obesity effects of fucoxanthin are apparently mediated by the hormones leptin and adiponectin through their common target AMK-activated protein kinase, resulting in downregulation of lipogenic enzymes and upregulation of lipolytic enzymes. Fucoxanthin also suppresses adipocyte differentiation and induces the expression of uncoupling proteins in visceral adipose tissue.The results of experimental studies suggest that consumption of fucoxanthin and its derivatives as nutritional supplements is a promising option for prevention and treatment of obesity and a wide variety of related pathologies, including metabolic syndrome, type 2 diabetes, and heart disease. Yet, clinical trials are warranted to assess a therapeutic value of fucoxanthin.