The Lifestyle Education About Prediabetes (Leap) Study

This research tested whether a standard version or very low-carbohydrate version of the Diabetes Prevention Program better improves outcomes like blood glucose control and body weight for patients with prediabetes. Participants had screening (included blood draw) and baseline testing with a continuous glucose monitor. Once these enrollment steps were completed, the participants were randomized to one of two groups: a standard National Diabetes Prevention Program (NDPP) or a very low-carbohydrate version. In addition to following the diet for 12 months, participants were asked to participate in hour-long weekly group classes over Zoom. After four months in the program, classes occurred about every month to help participants maintain the new diet. There were also check-ins and follow-up visits throughout the study.

Inclusion Criteria: * overweight, defined as BMI ≥ 25 kg/m² or ≥ 23 kg/m² if of Asian descent * HbA1c 5.7% to 6.4% (as measured in our baseline blood test) * willingness and ability to participate in group-based, online sessions using audio and video * ability to engage in at least light physical activities, such as walking * willingness to follow a prescribed diet, be randomized, self-weigh, track diet, and report physical activity minutes * physician approval to participate Exclusion Criteria: * Primary * history of type 1 diabetes or type 2 diabetes * use of anti-obesity medications or participation in another weight loss program or intervention * use of glucose lowering medications other than metformin * pregnant or planning to become pregnant during the intervention period * breastfeeding * use of oral corticosteroids * plan to start a weight loss medication during the study period * previous bariatric surgery or planning to have bariatric surgery during the study period * blood disorders that influence HbA1c, including frequent blood transfusions, phlebotomy, anemia, hemoglobinopathy, polycythemia * any condition for which the study team deems participation to be unsafe or inappropriate * Ability * inability to read, write, or speak English * inability to provide informed consent * adherence to a vegan or vegetarian diet * adherence to a very low-carbohydrate (keto) diet * difficulty chewing or swallowing * no influence over what foods are purchased, prepared, and/or served * above weight limit for DEXA (500 lbs) * Safety * untreated eating disorder or mental health conditions, such as depression with suicidal ideation, bipolar or schizophrenia with psychosis * use of warfarin * chronic kidney disease, stage 4 or higher * use of loop diuretics: 20mg or higher of furosemide or equivalent (Lasix (furosemide), Bumex (bumetanide), Edecrin or Sodium Edecrin (ethacrynic acid), Demadex or Soaanz (torsemide)) * any concerning values in baseline labs (participants will be referred to PCP and will be allowed to return for later enrollment if labs are no longer concerning): * triglycerides 600 mg/dL or higher * TSH of any abnormal value * Potassium of any abnormal value