Active, not recruitingNot applicableInterventional
What this study is about
The purposes of this study are: 1) to determine the mechanisms responsible for the development of cardiometabolic complications in some, but not all people with obesity; 2) determine the best dietary approach for cardiometabolic health; and 3) understand why some people have a stable metabolic phenotype over time whereas cardiometabolic health improves or worsens in others.
A promising-looking record is not the same as confirmed eligibility. The study team must review the full criteria and current recruitment status.
Basic eligibility
Age18 Years to 55 Years
SexAll
Healthy volunteersAccepted
ConditionObesity, Insulin Resistance
Full registry criteria
Inclusion Criteria: * Metabolically healthy lean subjects must have a body mass index (BMI) 18.5-24.9 kg/m², intrahepatic triglyceride (IHTG) content ≤5%, serum triglyceride (TG) concentration \<150 mg/dl, fasting plasma glucose concentration \<100 mg/dl, 2-hr oral glucose tolerance test (OGTT) plasma glucose concentration ≤140 mg/dl, and hemoglobin A1C (HbA1C) ≤5.6%. * Metabolically healthy obese subjects must have a BMI 30-49.9 kg/m²; IHTG content ≤5%, serum TG concentration \<150 mg/dl, fasting plasma glucose concentration \<100 mg/dl, 2-hr OGTT plasma glucose concentration ≤140 mg/dl, and HbA1C ≤5.6%. * Metabolically unhealthy obese subjects must have a BMI 30-49.9 kg/m²; IHTG content ≥5.6% and fasting plasma glucose concentration ≥100 mg/dl or 2-hr OGTT plasma glucose concentration ≥140 mg/dl or HbA1C ≥5.7%. Exclusion Criteria: * medical, surgical, or biological menopause; * previous bariatric surgery where the gastrointestinal tract is reconstructed such as Roux-en-Y, sleeve gastrectomy and biliopancreatic diversion surgeries; * laparoscopic adjustable gastric band (lab band) surgery within the last 3 years; * structured exercise ≥250 min per week (e.g., brisk walking); * unstable weight (\>4% change during the last 2 months before entering the study); * significant organ system dysfunction (e.g., diabetes requiring medications, severe pulmonary, kidney or cardiovascular disease); * cancer or cancer that has been in remission for \<5 years; * polycystic ovary syndrome; * major psychiatric illness; * conditions that render subject unable to complete all testing procedures (e.g., severe ambulatory impairments, limb amputations, or metal implants that interfere with imaging procedures; coagulation disorders); * severe anemia; * regular use of tobacco products; * excessive consumption of alcohol (≥3 drinks/day for men and ≥2 drinks/day for women); * use of medications that are known to affect the study outcome measures (e.g., steroids, non-statin lipid-lowering medications) or increase the risk of study procedures (e.g., anticoagulants) and that cannot be temporarily discontinued for this study; * use of antibiotics in last 60 days; * pregnant or lactating women; * vegans, vegetarians, those with lactose intolerance and/or severe aversions/sensitivities to eggs, fish, nuts, wheat and soy, and/or any individuals with food allergies that induce an anaphylactic response; * persons who are not able to grant voluntary informed consent
Treatments and study arms
Mediterranean diet
Behavioral
A Mediterranean-type diet will be consumed for 4 to 8 weeks in the weight stable state with all meals provided.
Low-carbohydrate, ketogenic diet
Behavioral
A low-carbohydrate, ketogenic diet will be consumed for 4 to 8 weeks in the weight stable state with all meals provided.
Low-fat diet
Behavioral
A low-fat diet will be consumed for 4 to 8 weeks in the weight stable state with all meals provided.
Annual follow-up testing for 5 years
Other
Annual follow-up testing with no restrictions on dietary intake during periods between annual testing.
