Effect of weight loss on circulating fatty acid profiles in overweight subjects with high visceral fat area: a 12-week randomized controlled trial

Abstract

Background: Significant associations between visceral fat and alterations in plasma fatty acids have been identified in overweight individuals. However, there are scant data regarding the relationships of the visceral fat area (VFA) with the plasma fatty acid profiles and desaturase activities following weight loss. We investigated the effect of weight loss with mild calorie restriction on the circulating fatty acid profiles and desaturase activities in nondiabetic overweight subjects with high VFA.

Methods: Eighty overweight subjects with high VFA (L4 VFA ≥100 cm²) were randomized into the 12-week mild-calorie-restriction (300 kcal/day) or control groups.

Results: Comparison of the percent of body weight changes between groups revealed that the weight-loss group had greater reductions in body weight. The VFA decreased by 17.7 cm² from baseline in the weight-loss group (P < 0.001). At follow-up, the weight-loss group showed greater reductions in serum triglycerides, insulin, and HOMA-IR than the control group. Significantly greater reductions in total saturated fatty acids, palmitic acid, stearic acid, total monounsaturated fatty acids, palmitoleic acid, oleic acid, eicosadienoic acid, and dihomo-γ-linolenic acid levels were detected in the weight-loss group compared with the control group after adjusting for baseline values. Following weight loss, C16 Δ9-desaturase activity was significantly decreased and Δ5-desaturase activity was significantly increased, and the changes were greater in the weight-loss group than in the control group.

Conclusions: The results suggest that mild weight loss improves abdominal obesity, overall fatty acid profiles, and desaturase activities; therefore, mild calorie restriction has potential health benefits related to obesity-related diseases in overweight subjects with high VFA.

Trial registration: NCT02992639. Retrospectively registered 11 December 2016.

Keywords: Fatty acid; Fatty acid desaturase; Obesity-related disease; Visceral fat; Weight loss.

Fig. 1

Correlation matrix among major clinical parameters, fatty acids, and fatty acid desaturases (changed values). Correlations were obtained by identifying a Pearson’s correlation coefficient. Red indicates a positive correlation, and blue indicates a negative correlation

Fig. 2

Summary of an indirect association between Δ5-desaturase activity and the risk of type 2 diabetes in the present study. Although no significant and direct correlation between Δ5-desaturase activity and the risk of type 2 diabetes was observed in this study, connections among Δ5-desaturase activity, weight, BMI, serum insulin level, and HOMA-IR score indicate an indirect inverse correlation between Δ5-desaturase activity and the risk of type 2 diabetes. Because the visceral fat area (VFA) has a significant negative correlation with Δ5-desaturase activity and Δ5-desaturase activity is inversely related to the risk of type 2 diabetes, VFA and the risk of type 2 diabetes might be positively correlated. Thus, mild calorie-restriction-induced weight loss that affects VFA at L4 decrease might lead to health benefits