No abstract

Objective Obesity in the United States continues to increase. Time restricted feeding (TRF) is a dietary intervention that has potential to serve as an effective weight loss strategy, however more data is needed to establish the effectiveness of a TRF eating pattern on health outcomes related to obesity. To our knowledge, manipulation of macronutrient distribution during a TRF intervention and the effect of TRF on sleep and mood have not been studied. Therefore, the objective of this study was to determine the effect of protein supplementation during TRF on mood, sleep, and appetite in overweight and obese adults. Methods Overweight and obese men and women (36.6±7.3 years; BMI: 32.8±6.5) participated in this randomized, controlled 12‐week dietary intervention. Participants were allocated to one of two groups: 1) control, TRF (n=7) and 2) TRF with whey protein supplementation (25 g/d; n=9). Protein supplements were consumed at the breaking of the fasting period each day. Anthropometrics, sleep (via Pittsburgh Sleep Quality Index Global Sleeping Score; PSQI GSS), total mood disturbances (TMD; via Profile of Mood States (POMS) including six affect states of depression, fatigue, anger, tension, confusion, and vigor subscales), and appetite (using visual analog scales) were assessed at 0, 4, 8, and 12 weeks. Sleep was also measured at 0 and 12 weeks via wrist Actigraphy. Body composition was measured via DXA at 0 and 12 weeks. Data was analyzed using two‐way ANOVA to assess the relationship. Results Overall, both interventions improved total body fat percentage (p<0.05) over 12 weeks. There was a significant difference in mood between intervention groups (p<0.001) and the control group total mood disturbance was significantly different (p<0.05) between week 1 and 12. However, there was no change in mood with protein supplementation over the span of 12 weeks. Sleep, self‐reported via PSQI, did not change from week 1 and week 12 within or between each of the interventions. Appetite did not show a significant difference between interventions or time points. Conclusions This pilot study suggests that protein supplementation during TRF has the potential to improve body composition in overweight and obese individuals. However, additional research is needed to determine the long‐term effect of protein supplementation in combination with TRF on mood, sleep, and appetite.

Objective: The objective of this study was to determine the impact of carbohydrate source in higher protein diets on body composition and markers of metabolic health in adults at risk for type 2 diabetes. We hypothesized that carbohydrate source would not impact body composition or markers of metabolic health. Methods: Male and female participants between the ages of 25 and 50 years old were recruited to participate in this 16 week, randomized, controlled, parallel design study (n=21; 14 females and 7 males; age 35.5 ± 10.5). To qualify participants had meet the following criteria: two or more characteristics of metabolic syndrome (body mass index (BMI) > 25, abdominal obesity, triglyceride level over 150 mg/dl, HDL cholesterol < 40 mg/dl in men and 50 mg/dl in women, systolic blood pressure of 130 mm Hg or diastolic blood pressure of 85 mm Hg, and/or fasting glucose > 100 mg/dL) and were consented to participate in this study. Participants were randomized to one of two treatments groups: 1) higher protein diet containing white potatoes (WP; n=11) or 2) higher protein diet with starch carbohydrate (SC; n=10). All diets were isoenergetic within individual participants. Energy content for weight maintenance per individual was calculated using the Harris Benedict equation x 1.35. Each participant was instructed to follow a macronutrient ratio of 30% protein, 30% fat, and 40% carbohydrates. Body composition was measured via DXA at baseline and 16 weeks. Biomarkers of metabolic health were measured at baseline, 4, 8, 12, and 16 weeks. Ethical approval for this study was obtained from the Office of Research Compliance Institutional Review Board of the University of Arkansas (Fayetteville, AR). This study was registered at clinicaltrials.gov (NCT03935048). Written consent was obtained from all participants prior to beginning the study. Results: There was no effect of carbohydrate source on fasting total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, glucose, or blood pressure after 16 weeks of dietary intervention. There was a significant effect of time and diet (p<0.05) on body weight (WP:-2.06±4.62; SC: +2.90±6.20 lbs) and an effect of diet on (p<0.05) on BMI (WP: -0.39±0.74; SC: 0.42±1.06). Participants following SC had increased loss of fat mass and an increase in fat-free mass compared to WP, but this change was not significantly different. Conclusion: Preliminary data suggests that carbohydrate source in a higher protein diet may influence body composition with no effect on biomarkers of metabolic health. Alliance for Potato Research and Education This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.