Omega-3 fatty acids may help you to lose weight because they regulate appetite. They are found in fish such as salmon, tuna, trout and mackerel. They are also found in other seafood including algae and krill, some plants and nut oils. Talk to your doctor before taking supplements. They can interfere with some medications and other supplements.
Omega-3 fatty acids are considered essential fatty acids because your body can't make them. You have to get them from food or supplements. They consist of eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA -- the two omega-3 fatty acids found in fish oil -- and alpha-linolenic acid, or ALA, which is found in some vegetable oils, flaxseed and walnuts. They are important for cognitive function and normal growth and development. Omega-3 fatty acids also reduce inflammation and may help lower risk of chronic diseases such as heart disease, cancer and arthritis.
Omega-3 fatty acids may increase satiety, or feelings of fullness, in people who are overweight or obese, according to a 2008 study published by D. Parra and colleagues in the journal Appetite. A group of participants who got high levels of omega-3 fatty acids reported lower hunger levels after eating. Further research is needed to determine if the appetite-regulating effects of omega-3 fatty acids lead to long-term weight loss.
Omega-3 fatty acids may suppress appetite because of their effect on leptin levels. Leptin is a hormone that affects appetite. When omega-3 fatty acid consumption is increased, leptin decreases, found a 2002 study published by Hongqin Wang and colleagues in the American Journal of Physiology- Endocrinology and Metabolism.
Getting enough omega-3 fatty acids may also prevent obesity because they prevent your body from storing fat. EPA and DHA may prevent enlargement and production of fat cells, according to a 2004 study published by Jana Ruzickova and colleagues in the journal Lipids.
Choose fish oil supplements based on the amount of DHA and EPA, not the amount of fish oil. In the 2008 Parra study, a group of people who consumed greater than 1,300 mg of long-chain omega-3 fatty acids a day reported lower hunger sensations than a group who got less than 260 mg a day of omega-3 fatty acids. Don't take more than 3 g of fish oil a day, because you could increase risk of bleeding, reduce immune system response and increase LDL, or "bad" cholesterol.