Fish oil supplements contain omega-3 fatty acids, a form of fat, some people do worry that the extra fat calories might contribute to problems with weight control. On the other hand, earlier research suggested that one of the metabolic benefits of omega-3s might be to promote weight loss. Latest findings: A new study published in The American Journal of Clinical Nutrition showed that supplementing with fish oil did not affect weight either way—it neither helped nor hindered weight loss.
Effects on Body Fat
Consuming fish oil may help reduce excess body fat in overweight individuals. A 2007 study published in the “American Journal of Clinical Nutrition” found that although taking fish oil supplements and exercising regularly both help improve cardiovascular health, fish oil supplements independently helped reduce body fat in overweight subjects. The study reports that taking 6,000 milligrams of the fish oil supplement, may help decrease body fat when combined with a regular exercise program.
The American Heart Association recommends the consume at least 500 mg of omega-3 fatty acids daily, either from oily fish or supplements. The metabolism of 1 g of fat produces 9 calories, so eating the recommended dose of omega-3s alone would confer 4.5 calories daily, an insignificant contribution to your total caloric intake. However, fish oil supplements contain other fats in addition to omega-3s. One serving of a fish oil supplement might contain 2.5 to 3 g of total fat, or 22.5 to 27 calories, the equivalent of less than 2 teaspoons of sugar.
Effects on Weight Gain
MedlinePlus reports that cancer patients who took 7.5 grams of fish oil each day showed slower rates of cancer-related weight loss. Most brands of fish oil supplements contain about 40 calories per teaspoon; therefore consuming excessive amounts of fish oil has the potential to increase your total calorie intake and lead to unwanted weight gain. However, 1 teaspoon of fish oil is likely enough to meet your daily omega-3 fatty acid requirement, which is 1,600 milligrams for men, 1,100 milligrams for women, 1,400 milligrams during pregnancy and 1,300 milligrams per day while breastfeeding, according to the Institute of Medicine.