(P04-004-25) Protein Supplementation During Time Restricted Feeding Decreases Body Fat but Does Not Improve Cardiometabolic or Inflammatory Markers in Adults With Overweight or Obesity

Objectives: Between 2021 and 2023, the prevalence of obesity in adults was 40.3%. Time restricted feeding (TRF) has become a popular weight loss strategy, with high rates of compliance. A dietary pattern higher protein is also popular for weight loss. Increased protein intake is linked with improvements in body composition and reduced cardiometabolic risk. The objective of this study was to determine if protein consumption in combination with TRF increases weight loss, reduced fat mass, and improves cardiometabolic and inflammatory markers in adults with overweight or obesity. We hypothesized that increased protein intake during TRF would further improve body composition and cardiometabolic health markers in adults with overweight or obesity.

Methods: Adults with overweight or obesity (BMI >25 kg/m²) were randomly assigned to a control group which followed TRF only (TRF; n = 8) or a TRF + whey protein supplementation group (TRF+PRO; n = 10; 25 g protein/day at beginning of eating cycle) for 12 weeks. Participants ate during a defined 8-hour period (12:00-20:00) and fasted for 16 hours. Body composition, anthropometrics, and biomarkers were assessed at baseline and 12 weeks. Data were analyzed using t-test to compare within groups two-way ANOVA to compare between groups (p < 0.05 was considered significant).

Results: Total body fat percentage decreased in TRF+PRO (-1.73 ± 1.76 %; p=0.012) but increased in the TRF group (5.53 ± 12.24 %; p= 0.277). Total body weight decreased in both TRF+PRO (-2.03 ± 3.03 kg; p=0.062) and TRF (-1.48 ± 1.62 kg; p=0.051). However, waist-to-hip ratio remained unchanged with either TRF or TRF+PRO. Similarly, there were no changes in cardiometabolic markers including glucose, total cholesterol, HDL, LDL, TG, cortisol, and glucagon with TRF or TRF + PRO. There was also no effect of TRF or TRF + PRO on inflammatory markers IL-6 and IL-10. Nevertheless, plasma levels of IL-15 decreased in TRF+PRO (-0.013±0.017; p=0.0362), but remained stable in TRF (0.008±0.021; p=0.319).

Conclusions: These findings suggest that 12 weeks of protein supplementation within a TRF dietary pattern may improve body composition, but neither the TRF nor TRF+PRO improves cardiometabolic or inflammatory biomarkers in adults with overweight or obesity.

Funding Sources: Arkansas Biosciences Institute