A Short Term Evaluation of a Structured Weight Loss Plan in Overweight and Obese Adults

It is well know that consumption of a calorically-restricted diet helps people lose weight. Such a diet with low carbohydrate lowers the serum uric acid concentration which is a factor associated with obesity and also represents a particular metabolic risk in women compared to men. The present weight loss study will determine whether women benefit more than men to short-term weight loss occurring during restriction of simple sugars.

Specifically, this study is designed to cause weight loss acutely through consumption of a diet that is restricted in calorie and simple sugars. Both men and women will be studied and their results compared to determine whether women benefit more with respect to arterial stiffness. Upon finishing the four-week diet intervention, body weight and blood lipids will be assessed two and four weeks later to compare the longer term effect on blood pressure.

Inclusion criteria

• Men and premenopausal women
• 30-55 years of age
• Sedentary lifestyle, defined as less than three sessions of activity per week, or sessions less than 20 minutes per occasion, or less than 5000 steps per day
• Must be able to speak, read, and write English (due to the small sample size and pilot nature of this study)
• Overweight/obese subjects with BMI 27.0 - 40.0 kg/m2 and any one of the following characteristics of the metabolic syndrome:

A. Serum HDL cholesterol <40 mg/dL (1 mmol/L) in men and <50 mg/dL (1.3 mmol/L) in women B. Blood pressure ≥130/85 mmHg C. Fasting plasma glucose ≥100 mg/dL (5.6 mmol/L) D. Waist circumference in men of >102 cm (40 in) and in women of >88 cm (35 in) E. Serum triglycerides (TG) ≥150 mg/dL (1.7 mmol/L).

Exclusion criteria

• Abnormal thyroid function or known liver disease
• Diabetes or fasting glucose ≥ 125 mg/dL
• Use of medications that interfere with protein, carbohydrate or lipid metabolism (e.g., fish oil capsules)
• Occasional or regular tobacco use
• History of gout
• Uncontrolled hypertension
• Pregnant or peri-menopausal
• Vegetarian food restrictions (the diets consumed contain some meat, eggs and dairy)
• Alcohol intake: females > 70 g/wk, males >140 g/wk
• Moderate or vigorous-intensity physical activity, defined as more than 150 minutes per week of moderate-intensity, or 75 minutes a week of vigorous-intensity aerobic physical activity, or an equivalent combination of both.