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

Abstract

Background The goal of the Frequency of Eating and Satiety Hormones (FRESH) Study is to understand the relationship between eating frequency (EF) and biomarkers of appetite and disease risk. This report gives the study rationale and design. Methods The FRESH study was conducted in n = 50 overweight and obese, but otherwise healthy, male and female adults aged 18–50 years. The protocol included four in-person clinic visits for protocol instruction, blood draws, anthropometry, and meal testing; all other activities were done at home. Participants completed two 21-day phases in random order with a two-week washout between phases. One phase was high EF (6 eating occasions/day) and the other was low EF (3 eating occasions/day). Each phase specified time of day for each eating occasion. Participants prepared their own meals throughout the study using study-provided individualized, structured meal plans ensuring that calories, macronutrients and micronutrients were identical during both study phases. Fasting blood was collected before and after each phase to test intervention effects on the biomarkers. At the end of each phase participants also completed extended appetite testing with meals prepared by the study clinic. Results Participants were recruited using print, radio, and digital ads. 60 participants consented to enroll; 10 dropped out due to work or school scheduling conflicts and 50 (target sample size) completed the study. Compliance was assessed by completion of daily on-line meal plan checklists. Conclusions The FRESH study will provide data on whether higher vs. lower daily EF in the context of constant energy and nutrient intake may be harmful or beneficial based on intervention effects on biomarkers of health and disease risk.

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

“…Increased frequency of intake is also highly correlated with overall energy intake and weight gain—both risk factors for T2D ( 51 – 54 ). Randomized controlled trials testing low compared with high eating frequency while maintaining eucaloric energy as well as comparable macronutrient distribution and diet quality are well suited to testing whether the number of eating occasions affects metabolic health ( 21 , 55 ). However, such studies are usually short term and typically employ surrogate end points (e.g., biomarkers, weight) as outcomes instead of disease end points; cohort studies such as WHI afford the opportunity to test these important associations with confirmed disease end points.…”