Effectiveness of 8-hour time-restricted eating combined with different dietary patterns on body composition, lipid metabolism, and oxidative stress in healthy adults: An exploratory study from an RCT

Abstract

Objectives

To evaluate the effectiveness of a 4-week intervention of time-restricted eating (TRE) alone or in combination with an elimination of ultra-processed foods or vegetarian diet, on body composition, lipid metabolism, and oxidative stress.

Methods

This was a randomized controlled trial including 70 participants comparing three diet groups maintained for a 4-week period: A, TRE alone; B, TRE with elimination of ultra-processed foods; and C, TRE with a vegetarian diet. Per-protocol analyses of body composition, plasma lipid levels, and oxidative stress markers were performed.

Results

Compared to baseline, Group B significantly reduced weight (P = 0.02), body mass index, waist and hip circumference, as well as fat ratio, total cholesterol, 4-hydroxynonenal an 8-Iso prostaglandin F 2α (all P < 0.05). Group B also increased high-density lipoprotein cholesterol (P < 0.05) and catalase (P = 0.002). Compared to Group A, Group B was more effective in decreasing body mass index (Δ: –0.1 ± 0.7 vs. –0.2 ± 0.3, respectively, P = 0.041) and waist circumference (Δ: –1.1 ± 4.0 vs. –3.5 ± 4.4, P < 0.001). Compared to Group A and B, the increase in superoxide dismutase (Δ: 12.74 ± 8.34, P < 0.05) and glutathione (Δ: 0.63 ± 0.40, P < 0.05) was significantly greater for Group C. Group C also produced a greater decrease in malondialdehyde (Δ: –0.79 ± 0.28) than the Group A (Δ: –0.32 ± 0.51, P < 0.001) and Group B (Δ: –0.20 ± 0.68, P < 0.001) diets.

Conclusions

Consumption of ultra-processed foods can increase body composition and lipid profile, despite TRE. A vegetarian diet in combination with TRE is effective in reducing oxidative stress injury.