The results, published in Healthcare, revealed that male participants had increased improvements in weight loss, body fat percentage, and waist size.
“These results could provide a guide for future nutritional intervention strategies aimed to improve metabolic health and reduce chronic low-grade inflammation by considering the n-6/n-3 PUFA ratio content as a necessary calculation for a proper diet,” the researchers from the University Center for Health Sciences in Mexico wrote.
Obesity and inflammation
Evidence suggests that obesity is linked to chronic low-grade inflammation. Secretion of inflammatory cytokines in tissues can alter lipid metabolism and impair insulin signaling, limiting glucose absorption and leading to insulin resistance.
The typical Western diet provides an approximate omega-6/3 ratio of 20:1, predisposing inflammatory responses and low-grade inflammation. Overconsumption of seed oils rich in omega-6 in processed foods and a lack of omega-3 sources can create a pro-inflammatory state.
Studies indicate that over-expression of inflammatory cytokines is associated with abdominal obesity and subcutaneous fat thickness, posing a potential risk of metabolic and cardiovascular diseases.
Study details
The eight-week study was a randomized, active placebo-controlled, double-blind parallel clinical trial with eight weeks of follow-up, and included 40 participants aged 25 to 50.
The recruited participants were all categorized as having obesity defined by body mass index and/or abdominal obesity defined by appropriate criteria.
The intervention consisted of the same diet for both groups with either marine omega-3 supplementation or placebo.
The diet involved a 200 kcal/day restriction for the first four weeks and an additional 200 kcal/day restriction for the next four weeks, based on estimated basal caloric expenditure. It had an omega-6 to omega-3 ratio of 5:1.
The omega-3 supplementation dose was 1.8 g daily, taken as three capsules with each main meal with 1080 mg of eicosapentaenoic acid (EPA) and 720 mg of docosahexaenoic acid (DHA). The active placebo group took 1600 mg of vegetable n-3 alpha-linolenic acid (ALA).
The researchers assessed food diaries and dietary adherence, made anthropometric and biochemical measurements, and evaluated inflammatory markers. They noted a 70% adherence in both groups.
The results showed a significant increase in omega-3 intake in both groups, achieving ideal proportions, and a decrease in omega-6 in the study group. By the end of the study, both groups achieved a dietary omega-6 to omega-3 ratio of 5:1.
Some anthropometric and biochemical measurements were improved in both groups, but “the prevalence of abdominal obesity was significantly reduced by 35% in the omega-3 group, compared to a 5.6% reduction in the active placebo group,” the study noted.
The researchers found that men in the marine omega-3 group had a greater weight loss of −4.2 kg than the active placebo group, which had a weight loss of −2.2 kg. Additionally, their body fat percentage, waist circumference, and HDL cholesterol improved more than the placebo group.
Inflammatory markers such as interleukin-6 showed more improvements in the omega-3 group compared to placebo.
The authors recommend further studies with a broader analysis of inflammatory markers and hypocaloric diets to provide a more comprehensive understanding of dietary interventions and inflammation.
Source: Healthcare 2025, 13(2), 103; https://doi.org/10.3390/healthcare13020103; “Effect of a Diet Supplemented with Marine Omega-3 Fatty Acids on Inflammatory Markers in Subjects with Obesity: A Randomized Active Placebo-Controlled Trial”; Authors: J. Torres-Vanegas et al.