The primary outcome was total energy expenditure, assessed by doubly-labeled water methodology. Secondary outcomes included resting energy expenditure and physical activity, chronic disease risk factors, and variables to inform an understanding of physiological mechanisms by which dietary carbohydrate-to-fat ratio might influence metabolism. Weight change during the ad libitum feeding phase was conceptualized as a proxy measure of hunger.

Background Nearly 50% of U.S. women enter pregnancy as overweight or obese (OW/OB). There is a critical need to understand how to motivate OW/OB pregnant women for exercise behavior to improve their health and reduce adverse pregnancy outcomes. Purpose: To examine salient Theory of Planned Behavior belief predictors of normal weight (NW) and OW/OB pregnant women’s exercise behavior (EXB) across pregnancy. Methods Pregnant women (N = 357) self-reported their exercise beliefs and behavior during each pregnancy trimester. Pearson correlations were used to examine exercise beliefs-behavior associations. Stepwise regressions were used to identify trimester (TRI) 1 and TRI 2 belief predictors of TRI 2 and TRI 3 EXB, respectively, for each weight status group. Belief endorsement was examined to identify critical beliefs. Results TRI 1 EXB beliefs explained 58% of the total variance (22% NW, 36% OW/OB) in TRI 2 EXB. TRI 2 EXB beliefs explained 32% of the total variance (17% NW, 15% OW/OB) in TRI 3 EXB. Individual beliefs varied by weight status and trimester. Control beliefs emerged with the lowest endorsement; making them most critical to target for exercise interventions. Conclusion: Prenatal exercise interventions should be weight status specific and target salient beliefs/barriers unique to the pregnancy trimesters.

A research team from Boston Children's Hospital and Harvard Medical School conducted a community-based feeding study in collaboration with Framingham State University (FSU) and Sodexo, the food service contractor at FSU. The study was a randomized controlled trial, implemented on the FSU campus. For the final year of the study, a satellite feeding site was established at Assabet Valley Regional Technical High School. The purpose of the study was to assess the biological effects of different macronutrient diets. An academia-industry partnership was developed to overcome common challenges associated with hospital-based feeding studies. Benefits included the following: a study site outside of Boston (reducing inconvenience for participants), access to a large commercial kitchen and study-specific kiosk (promoting efficiency), collaboration with Sodexo chefs (ensuring palatability of meals), and opportunity to procure food from contracted vendors. The research (academia) and food service (industry) teams worked together to design, plan, and execute intervention protocols using an integrated approach. During execution, the research team was primarily responsible for overseeing treatment fidelity, whereas the food service team provided culinary expertise, with a strong focus on hospitality and food quality. The study was conducted in 3 cohorts between August 2014 and May 2017. Participants received all of their food for ∼30 wk, totaling >160,000 meals. For all 3 cohorts combined, 234 participants provided informed consent, 229 started a standard run-in weight-loss diet, 164 lost a mean ± SD 12% ± 2% of baseline body weight and were randomly assigned to different macronutrient diets for weight-loss maintenance, and 148 completed the study. During the final and largest cohort, as many as 114 participants received daily meals concurrently. The daily cost per participant for preparation and service of weighed meals and snacks was ∼$65. This academia-industry partnership provides a model for controlled feeding protocols in nutrition research, potentially with enhanced cost-effectiveness, practicality, and generalizability. This trial was registered at http://www.clinicaltrials.gov as NCT02068885.