Fish oil supplementation has a lot of health benefits, like lower blood pressure, reduced triglycerides, and reduced risk of heart disease. Fish oil is also recommended to women during pregnancy; however, some studies suggest that fish oil supplementation may increase body weight in the offspring. This study aims to evaluate the effect of fish oil supplementation on body composition and anthropometry in offspring.

This is a double-blinded, controlled, randomized trial that included a total of 736 pregnant women and their offspring. The women were randomly assigned to n-3 LCPUFA (fish oil) or control (olive oil) daily from the 24th week of pregnancy until birth. The primary outcome measures of the study were the height, weight, head, and weight measurements of the offspring.

The fish oil supplementation group reported an increased mean BMI score between 0 and 6 years of age compared with the control group (0.14). At age 6 years, fish oil supplementation was associated with an increased BMI score (0.19), weight/height (3.48), waist circumference (0.6). However, it was not related to the rise of obesity in children.

The research concluded that fish oil supplementation from the 24th week of pregnancy until birth was associated with an increased BMI score, height/weight, and waist circumference, but not with obesity.