Randomized Trial Testing the Effects of Eating Frequency on Two Hormonal Biomarkers of Metabolism and Energy Balance

Abstract

Background Eating frequency may influence obesity-related disease risk by attenuating post-prandial fluctuations in hormones involved in metabolism, appetite regulation, and inflammation. Materials/Methods This randomized crossover intervention trial tested the effects of eating frequency on fasting plasma insulin-like growth factor-I (IGF-1) and leptin. Fifteen participants (4 males, 11 females) completed two eucaloric intervention phases lasting 21 days each: low eating frequency (“low-EF”; 3 eating occasions/day) and high eating frequency (“high-EF”; 8 eating occasions/day). Participants were free-living and consumed their own meals using individualized structured meal plans with instruction from study staff. Participants completed fasting blood draws and anthropometry on the first and last day of each study phase. The GEE modification of linear regression tested the intervention effect on fasting serum insulin-like growth factor I (IGF-I) and leptin. Results Mean (± SD) age was 28.5 ± 8.70 years, and mean (± SD) BMI was 23.3 (3.4) kg/m2. We found lower mean serum IGF-1 following the high-EF condition compared to the low-EF condition (p<0.001). There was no association between EF and plasma leptin (p=0.83). Conclusion These results suggest that increased eating frequency may lower serum IGF-1, which is a hormonal biomarker linked to increased risk of breast, prostate and colorectal cancer.

Leptin—A Potential Bridge between Fat Metabolism and the Brain’s Vulnerability to Neuropsychiatric Disorders: A Systematic Review

“…Perrigue et al [ 81 ] investigated the effect of eating frequency on metabolic markers in subjects without obesity. Meals/day frequencies were negatively correlated with serum IGF-1 levels, but no associations were found for leptin levels.…”

“…It is suggested that changes in leptin are independent of circadian rhythms and stress factors; however, the endogenous modulation of leptin might be essential in preventing various chronic metabolic and brain diseases [ 56 , 73 , 75 , 78 , 81 ]. Therefore, it is necessary to understand the physiology of leptin and a healthy metabolism.…”

Associations of Number of Daily Eating Occasions with Type 2 Diabetes Risk in the Women’s Health Initiative Dietary Modification Trial

“…The protocol specified that total energy and macronutrient distribution were to be kept constant on both study arms. We found that compared with the grazing pattern, the meals pattern led to significantly higher serum insulin-like growth factor 1, which is secreted in response to an insulin stimulus ( 46 ). Taken together, the data to date are not consistent.…”

“…Heden et al ( 21 ) reported that the incremental AUC for insulin was significantly larger following a 3 meal per day experimental condition in 8 obese women compared to a 6 meal per day condition. We previously reported a randomized crossover trial comparing meals (eating 3 times per day) with grazing (eating 8 times per day) ( 46 ). A registered dietitian gave detailed guidance to study participants as they prepared and consumed their own meals throughout the 2 study periods.…”

Rationale and design of the frequency of eating and Satiety Hormones (FRESH) study: A randomized cross-over clinical trial

“…Therefore, we have designed and implemented a randomized controlled trial in healthy, free-living individuals that will test the effect of EF on blood-based biomarkers of inflammation, adiposity and satiety. These outcomes were selected based on our prior pilot work [ 11 , 12 ] as well as that of others [ 4 , [13] , [14] , [15] ]. Here we describe the study design and protocol.…”