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.