Background & aims: Whether moderate weight loss or a reduction in IL-6 improves the serum iron status in overweight (OW) and obese adults supplemented with or without fish oil is explored.
Methods and results: In total, 93 OW/obese Taiwanese adults with ≥2 metabolic components are randomized to a 12-week calorie-restricted diet with meal replacement alone (CRMR, n = 45) or supplemented with fish oil (CRMRF, n = 48). Mean reductions in the %body weight and serum IL-6 are 7.5% versus 5.9% and 21% versus 35% for the CRMR and CRMRF groups, respectively. In the CRMRF group, a moderate loss of IL-6 (reduced ≥35%) also significantly improves the serum iron and transferrin saturation compared to those with loss of <35% in the mean serum IL-6 or those of the CRMR group who has a moderate loss of IL-6 (reduced ≥21%) (all p < 0.05). In contrast, modest weight loss does not improve the serum iron status.
Conclusions: Fish oil is ineffective as an adjunct for weight or fat loss but has beneficial effects on preserving the lean body mass. A significant improvement in the iron status is only observed in those with moderate loss of serum IL-6 supplemented with fish oil.
Keywords: calorie-restricted diet with meal replacement; interleukin-6; lean body mass; omega-3 fatty acids; serum iron; weight loss.
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