Fish Oil & Weight Loss

The obesity epidemic is a primary contributor to disease worldwide and has inspired a flood of studies examining possible weight loss solutions. Omega-3 fatty acids are the active components in fish oil that became well known for their health benefits. Researchers have looked at omega-3s in terms of aiding weight loss with an aim toward curbing obesity-related diseases. The results are inconclusive.


Exercise, Weight Loss and Omega-3

Australian researchers published results of a study examining the effects of fish oil on weight loss in combination with diet and exercise in the May 2007 issue of “American Journal of Clinical Nutrition.” In addition to being overweight, the participants were diagnosed with metabolic syndrome, which is a cluster of symptoms associated with obesity, including hypertension and insulin resistance or heightened insulin levels. The results showed that the total proportion of fat in the body, particularly in the abdominal region, was reduced significantly in the fish oil plus exercise group but not by fish oil or exercise alone.

Belly Fat Again Reduced

Researchers from INSERM, the French equivalent of the U.S. National Institutes of Health, published a study in the December 2007 edition of the “American Journal of Clinical Nutrition” that examined the effects of omega-3 fish oil supplementation on weight loss in women with diabetes. Twenty-seven women were enrolled and randomly assigned to receive either fish oil providing 1.8 grams of omega-3s per day or placebo for two months. Belly fat has been implicated as a major contributor to metabolic diseases, and the researchers reported that the belly fat of the fish oil group was significantly reduced.

Omega-3 and Low Calorie Dieting

A team at the Obesity Management Center in Prague published a study in the April 2006 issue of “Physiological Research” investigating the effects of omega-3 supplementation on dieters without exercise. They enrolled 20 obese women and randomly assigned them to a very-low-calorie diet plus omega-3 supplements or to the same very-low-calorie diet plus placebo capsules. The researchers reported that after three weeks, the omega-3-supplemented women realized significantly greater weight losses and reductions in their body mass indices and hip circumferences compared with the placebo group. They also reported finding signs of significantly greater fat burning in the omega-3 group.

No Benefit

U.S. researchers reporting in the February 2011 issue of “American Journal of Clinical Nutrition” investigated if omega-3 fish oil supplements would speed up weight loss when combined with diet and exercise. The researchers enrolled 128 people who were either overweight or obese. They were randomly assigned to receive either five omega-3 capsules per day or five placebo capsules. Both groups received diet and exercise counseling, and 81 of the 128 completed the full six-month trial. The researchers reported that both groups lost more than 5 percent of their body with no significant differences between the fish oil and placebo groups.


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This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or