^ Jump up to: a b Committee on the Framework for Evaluating the Safety of Dietary Supplements, Food and Nutrition Board, Board on Life Sciences, Institute of Medicine and National Research Council of the National Academies (2004). Dietary supplements a framework for evaluating safety. Washington, D.C.: National Academies Press. p. ES-1-ES-3. ISBN 978-0-309-09206-7.

"Staying well-hydrated helps your body function properly, and it also helps make sure you don’t overeat," Pam Bede, M.S., R.D. with Abbott’s EAS Sports Nutrition, tells SELF. But it's not just that staying hydrated keeps you from overeating. According to Maxine Yeung, M.S., R.D., owner of The Wellness Whisk, sometimes you may feel hungry when, in fact, you're actually thirsty. Basically, no harm can come from drinking a glass of water.

Fish oil is a commonly used fatty acid supplement because it is a source of omega-3 fatty acids.[43] Fatty acids are strings of carbon atoms, having a range of lengths. If links are all single (C-C), then the fatty acid is called saturated; with one double bond (C=C), it is called monounsaturated; if there are two or more double bonds (C=C=C), it is called polyunsaturated. Only two fatty acids, both polyunsaturated, are considered essential to be obtained from the diet, as the others are synthesized in the body. The "essential" fatty acids are alpha-linolenic acid (ALA), an omega-3 fatty acid, and linoleic acid (LA), an omega-6 fatty acid.[43][44] ALA can be elongated in the body to create other omega-3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
For example, while increased consumption of fruits and vegetables are related to decreases in mortality, cardiovascular diseases and cancers, supplementation with key factors found in fruits and vegetable, like antioxidants, vitamins, or minerals, do not help and some have been found to be harmful in some cases.[86][87] In general as of 2016, robust clinical data is lacking, that shows that any kind of dietary supplementation does more good than harm for people who are healthy and eating a reasonable diet but there is clear data showing that dietary pattern and lifestyle choices are associated with health outcomes.[88][89]