“None of the studies reported a statistically signiﬁcant effect of ﬁsh oil treatment relative to placebo. Further analysis showed no relationship between body weight change with intervention duration, or n-3 dosage, nor any funnel effect with study sample size. This analysis does not support the hypothesis that daily n-3 oil supplementation reduces body weight and BMI in the overweight and obese.”
First, drawing such a definitive conclusion based on data from only 4 studies, that are heterogeneous, is misleading. Second, the studies didn’t provide enough information to allow the meta-analysis to adjust for factors that might abrogate the fat loss effect of the long-chain omega-3 fatty acids EPA and DHA, found in fatty fish and fish oil.