Among 626 participants of the Men’s Lifestyle Validation Study (2011-2013), we evaluated the validity and reproducibility of a self-administered 152-item semiquantitative food frequency questionnaire (SFFQ) using two 7-day dietary records (7DDRs), four automated self-administered 24-hour dietary recalls (ASA24s), four 24-hour urine samples, one doubly-labeled water measurement (repeated in 104 participants), and two fasting blood samples, collected over 15 months. Compared to 7DDRs, SFFQs underestimated energy intake, macronutrients, and sodium intake, but overestimated some micronutrients. The mean of Spearman correlation coefficients was 0.66 (range 0.38 to 0.88) between 46 energy-adjusted nutrients estimated from 7DDRs and the final SFFQ, de-attenuated for within-person variation in the 7DDRs. These deattenuated correlations were similar using ASA24s as the comparison. Relative to biomarkers, SFFQs underestimated energy, sodium, and protein intakes, and the sodium:potassium ratio. The energy-adjusted correlations between the final SFFQ and the biomarkers were slightly lower than the correlations between the SFFQ and 7DDRs. Using method of triads to calculate validity coefficients (VC), the median VC between SFFQ and true intake was 0.65 and 0.69 using 7DDRs or ASA24s as the third method. These data indicate that this SFFQ provided reasonably valid estimates for a wide range of nutrients when evaluated by multiple comparison methods.

Drinking within recommended limits is highly prevalent in much of the world, and strong epidemiological associations exist between moderate alcohol consumption and risk of several major chronic diseases, including coronary heart disease, diabetes, and breast cancer. In many cases, plausible biological mediators for these associations have been identified in randomized trials, but gold-standard evidence that moderate drinking causes or prevents any chronic disease remains elusive and important concerns about available evidence have been raised. Although long-term randomized trials to test the observed associations have been termed impossible, clinical investigators have now successfully completed randomized trials of complex nutritional interventions in a variety of settings, along with trials of alcohol consumption itself of up to two years duration. The successful completion of these trials suggests that objections to the execution of a full-scale long-term clinical trial of moderate drinking on chronic disease are increasingly untenable. We present potential lessons learned for such a trial and discuss key features to maximize its feasibility and value.

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.