Not all oils are created equal, and different types are handled differently by the body. A recent study of fish oil supplementation found that folks who supplement with fish oil and also walked briskly 3 times a week for 45 minutes lost 1.5 kg (about 3 pounds) over 12 weeks without any other changes to their diet. One control group took sunflower oil and walked, and another control group took fish oil and didn't walk. The only group with highly significant fat loss was the group that BOTH walked and supplemented, though the walking group with no fish oil saw a very slight improvement.
There are many theories why this should be so. One is that omega 3 fatty acids help activate fat burning enzymes in our body. Another is that when our body is replete with healthy oils, it lets go of fat more easily. This occurs with some other healthy fats as well. For example, in studies where walnuts were studied to lower cholesterol, those eating large amounts of extra (high fat) walnuts each day also did not gain weight.
The dose in this study was 6 grams of fish oil yielding about 1.9 grams of omega 3 fatty acids, including DHA and EPA. This would be 2-4 servings of tuna or salmon a week. I am very picky about which fish oil I recommend, as many (if not most) are rancid and/or have toxins in them. If you would not eat a piece of fish that tastes like the oil, then the oil is likely rancid and should not be used.
Am J Clin Nutr. 2007 May;85(5):1267-74.
Combining Fish-Oil Supplements with Regular Aerobic Exercise Improves Body Composition and Cardiovascular Disease Risk Factors
Hill AM, Buckley JD, Murphy KJ, Howe PR.
Nutritional Physiology Research Centre and the Australian Technology Network Centre for Metabolic Fitness, University of South Australia, Adelaide, Australia.
BACKGROUND: Regular exercise and consuming long-chain n-3 fatty acids (FAs) from fish or fish oil can independently improve cardiovascular and metabolic health, but combining these lifestyle modifications may be more effective than either therapy alone.
OBJECTIVE: We examined the individual and combined effects of n-3 FA supplements and regular exercise on body composition and cardiovascular health.
DESIGN: Overweight volunteers [body mass index (BMI; in kg/m(2)): >25] with high blood pressure, cholesterol, or triacylglycerols were randomly assigned to one of the following interventions: fish oil (FO), FO and exercise (FOX), sunflower oil (SO; control), or SO and exercise (SOX). Subjects consumed 6 g tuna FO/d (approximately 1.9 g n-3 FA) or 6 g SO/d. The exercise groups walked 3 d/wk for 45 min at 75% age-predicted maximal heart rate. Plasma lipids, blood pressure, and arterial function were assessed at 0, 6, and 12 wk. Body composition was assessed by dual-energy X-ray absorptiometry at 0 and 12 wk only.
RESULTS: FO supplementation lowered triacylglycerols, increased HDL cholesterol, and improved endothelium-dependent arterial vasodilation (P<0.05). Exercise improved arterial compliance (P<0.05). Both fish oil and exercise independently reduced body fat (P<0.05).
CONCLUSIONS: FO supplements and regular exercise both reduce body fat and improve cardiovascular and metabolic health. Increasing intake of n-3 FAs could be a useful adjunct to exercise programs aimed at improving body composition and decreasing cardiovascular disease risk.
PMID: 17490962 [PubMed - indexed for MEDLINE]
Jacob Teitelbaum, M.D. is one of the world's leading integrative medical authorities on fibromyalgia and chronic fatigue. He is the lead author of four research studies on their treatments, and has published numerous health & wellness books, including the bestseller on fibromyalgia From Fatigued to Fantastic! and The Fatigue and Fibromyalgia Solution. Dr. Teitelbaum is one of the most frequently quoted fibromyalgia experts in the world and appears often as a guest on news and talk shows nationwide including Good Morning America, The Dr. Oz Show, Oprah & Friends, CNN, and Fox News Health.