Clinical Research Directory

Inclusion Criteria: * Aged 30-70 years old * Prediabetic as determined by HbA1c between 5.7-6.4% or fasting glucose between 100-125 mg/dl with HbA1c \>= 5.1% * Fasting insulin less than 100.0 mU/l and, if HbA1c \<5.7%, must also have fasting insulin \>= 8.0 mU/l * BMI between 30-60 kg/m\^2 * Wake up at a regular time between 5-8 am Exclusion Criteria: * Been diagnosed with diabetes or on diabetes medication or any medication known to affect glucose or 24-hour rhythms in blood pressure * On weight loss medication * Change in the dosage of a chronic medication within the past 2 months * Have a clinically significant laboratory abnormality (e.g., abnormal hemoglobin levels) * Significant gastrointestinal disease, major gastrointestinal surgery, or gallstones * Significant cardiovascular, renal, cardiac, liver, lung, adrenal, or nervous system disease that might compromise the participant's safety or data validity * Evidence of cancer (other than non-melanoma skin cancer) within the last 5 years * Pregnant or breastfeeding * Diagnosed psychiatric conditions * Sleep disorder, circadian disorder, or regularly sleep less than 6 hours per night * Major change in health or medical history in the past 3 months * Currently perform overnight shift work * Regularly eat within a \<10.5-hour period each day * Lost or gained more than 4% of weight in the past 2 months * Traveled more than 2 time zones away in the 2 months prior to enrolling in this study * Will travel outside the Central time zone in the 2 weeks prior to testing * Will travel more than 1 time zone away during this study * Behavioral factors or other circumstances that may make it difficult for you to follow the study requirements