Grape seed oil (GSO) is reported to improve oxidative stress and lipid profile. However, the ameliorating effect of GSO on inflammation and insulin resistance has not being noticed so far. We aimed to examine the effects of GSO consumption on inflammation and insulin resistance in overweight or obese females. The subjects (n = 44) were randomly assigned into intervention group as "GSO" (consuming 15% of energy from GSO) and control group as sunflower oil "SFO" (consuming 15% of energy from SFO) through a weight loss diet for 8 weeks. Anthropometric measurements, dietary recall and fasting serum glucose, insulin, high sensitive C-reactive protein (hs-CRP) and tumor necrosis factor-alpha (TNF-α) were assessed before and after the intervention. Homeostatic model assessment of insulin resistance (HOMA-IR) scores, hs-CRP and TNF-α decreased in the GSO group. The hs-CRP was lower in GSO than the SFO group (p < 0.03). GSO consumption seems to improve inflammatory condition and insulin resistance in overweight/obese women.

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Clinical trials have indicated conflicting results on the effects of conjugated linoleic acid (CLA) on obesity. The present study aimed to systematically review controlled clinical trials examining the effects of CLA on anthropometric indices and body composition in overweight and obese subjects. Pubmed, Scopus, Web of science, and Cochrane databases were searched between 2000 and December 2017 with no language restriction. Placebo-controlled clinical trials that reported anthropometric indices and body composition in overweight and obese subjects were included. Random-effect model was used to pool the effect estimates. Of 4032 publications, 13 trials were included for the meta-analysis. Pooled effect sizes indicated that CLA significantly reduced body weight (WMD: -0.52 kg, 95% CI: -0.83, -0.21; I: 48.0%, p=0.01), BMI (WMD: -0.23 kg/m, 95% CI: -0.39, - 0.06; I: 64.7%, p=0.0001), FM (WMD: -0.61 kg, 95% CI: -0.98, -0.24; I: 53.8%, p=0.01) and increased LBM (WMD: 0.19 kg, 95% CI: 0.04, 0.34; I: 81.4%, p=0.0001) compared to the placebo group. However, the effects of CLA on WC (WMD: 0.05 cm, 95% CI: -0.01, 0.1; I: 0%, p=0.93) was not significant. Additionally, its impact on body weight in subjects older than 44 year (WMD: -1.05 kg, 95% CI: -1.75, -0.35; I: 57.0%, p=0.01), with longer duration (more than 12 weeks) (WMD: -1.29 kg, 95% CI: -2.29, -0.29; I: 70.3%, p=0.003) and dosage more than 3.4 g/day (WMD: -0.77 kg, 95% CI: -1.28, -0.25; I: 62.7%, p=0.004) were greater than comparative groups. Supplementation with CLA can slightly reduce body weight and FM and increase LBM in overweight and obese subjects. However, its efficacy was not clinically relevant. Further studies with high methodological quality are needed to shed light on the effects of CLA on anthropometric indices in overweight and obese subjects.

This research investigated the effect of co‐supplementation of selenium with zinc on weight control and the inflammatory and oxidative status in relation to obesity. Male Wistar rats (N = 32) were randomly divided into four groups after induction of obesity model: 1) “Zn” was supplemented with zinc sulfate (15 mg/kg BW), 2) “Se” supplemented with selenium as sodium selenate (0.5 mg/kg BW), 3) “Zn + Se” which received Zn (15 mg/kg BW) + Se (0.5 mg/kg BW), and 4) “HFD” as the control group. The intervention was done for eight weeks. At the end of treatment, serum and tissue level of Zn, Se, SOD, GSH‐Px, MDA, leptin, TNF‐α, and IL‐6 was evaluated. Weight and food intake were significantly reduced in the Se group(p < .001), while in the Zn group, weight gain due to obesity was prevented compared to the control group (p = .48). There was a significant and stronger increase in SOD, GSH‐Px levels and a remarkable decrease in MDA, leptin, TNF‐α, and IL‐6 in the group receiving the combination of two supplements than either alone(p < .001). Leptin had a positive correlation with inflammatory factors and lipid peroxidation marker and showed an inverse relationship with Zn and Se levels and anti‐oxidative enzymes(p < .05). The analysis showed the mediating role of leptin in the effects of zinc. Co‐supplementation of selenium and zinc may have a synergistic effect in reduction of oxidative and inflammatory markers. Regarding the effect of zinc on inflammatory factors and lipid peroxidation, leptin can play a mediating role.

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