Introduction
Excess body fat especially intra-abdominal fat is central to the progression of prediabetes to Type 2 Diabetes Mellitus (T2DM). One measure of impaired glucose tolerance is impaired fasting glucose (IFG) defined a fasting blood sugar > 100 mg/dl. The Center for Disease Control (CDC) estimates 86 million or more than a third of the U.S. population to have prediabetes (1) which has been observed to progress to T2DM at a rate of 5–10% annually (2). The prevalence of prediabetes is projected to exceed 470 million worldwide by 2035. Obesity and prediabetes have also been associated with hypertension, lipid disorders, obstructive sleep apnea, fatty liver disease and cancer (3). Microvascular changes have been identified prior to the development of T2DM are including nephropathy, neuropathy, erectile dysfunction, and retinopathy (4). Prediabetes and obesity are also associated with an increased risk for cardiovascular diseases (5, 6). A continuous inverse correlation between glucose levels and cognitive test results in the absence of diabetes has been demonstrated in cross-sectional population studies (7).
The most recent Endocrine Society clinical practice guidelines for the primary prevention of atherosclerotic cardiovascular disease (ASCVD) and T2DM in patients at metabolic risk recommend prescribing lifestyle modification to reduce blood glucose prior to instituting pharmacological treatment (8). These recommendations are based on several hallmark trials including the U.S. Diabetes Prevention Program (DPP) and Look AHEAD (Action for Health in Diabetes) study. The U.S. Diabetes Prevention Program (DPP) reported that lifestyle modification resulted in a 58 percent reduction in the incidence of T2DM and was more effective than metformin (9). The Da Qing Diabetes Prevention Outcome Study in China demonstrated that lifestyle intervention in people with impaired glucose tolerance delayed the onset of T2DM and reduced the incidence of cardiovascular events, microvascular complications, and all-cause mortality (10).
This retrospective study analyzed the clinic records of patients enrolled in the UCLA Medical Weight Management program which utilizes a unique prescriptive protein-enriched low calorie and very low calorie diets in combination with supportive behavioral groups, medical and dietetic supervision on an individualized basis. Protein prescriptions were based on lean body mass assessments using bioelectrical impedance analysis by providing 1 gram per pound of lean body mass per day which averaged about 2 grams per kg body weight per day.