Many bioactive compounds extracted from marine organisms have been found to be able to protect against a range of metabolic disorders including obesity and diabetes mellitus.  The bioactive ingredients can be polyunsaturated fatty acids (PUFAs), sterols, proteins, polysaccharides, antioxidants, and pigments which have preventative or therapeutic effects against metabolic disorders.  The most commonly known dietary supplements that are used in weight loss pills or wnti-diabetic supplements include fucoxanthin from brown seaweeds, astaxanthing form marine algae, marine collagen peptides, from deep-sea fish, dieckol from Echlonia cava, krill oil from Antartic krill, fucoidan from marine brown algae, hyrtiosal from marine sponge, SQA and SHQA from Sargassum yesoense.  (David Liu, PHD)Wang, Hang, Zhi-ming Fu, and Chun-chao Han. "The Potential Applications of Marine Bioactives Against Diabetes and Obesity." American Journal of Marine Science 2, no. 1 (2014): 1-8.