An average of available dietary recalls and records at each time point were used to calculate adherence scores at 6 time points from NDS-R diet data to measure degrees of adherence to the dietary recommendations. A description of score components is provided in Supplemental Tables 1 and 2. A standardized range of scores was created for both diets (1–10, with 10 being the highest level of adherence). Adherence scores are reported as means ± SDs. While participants were completing the WFKD phase of the study, they were provided with blood ketone monitors and strips (Abbott Precision Xtra Blood Glucose & Ketone Monitoring System) to measure ketones 3 times per week before breakfast (fasting state). Additionally, participants completed a fasting venous blood draw at 7 time points throughout the study, and levels of β-hydroxybutyrate were analyzed from plasma samples. These 2 measures provided feedback on whether participants lowered their carbohydrate intake enough to be in ketosis and provided an objective, biological measurement of adherence to the WFKD. Data on ketone blood levels during the WFKD phase are described in detail elsewhere (20 (link)). There was no parallel biochemical parameter for Med-Plus adherence. Data on food and diet satisfaction and alterations to diet and physical activity due to COVID-19 are described in detail elsewhere (20 (link)).