Herman L. Johnson

Changes in human body composition during calorie restriction with two levels of protein

Abstract Four women (140–160% of ideal weight, 32–42 yr old) were monitored for 6 weeks of weight maintenance, 12 weeks of calorie restriction (1000–1200 kcal/day) and 6 weeks of maintaining reduced body weights. To observe the effects of dietary protein levels in the weight reducing diet upon changes in body composition and energy stores, the restriction diet of two women was reduced 50% for all macronutrients while that of the remaining two women was reduced about 60% in fat and carbohydrate while maintaining the protein intake at the prerestriction level. Body composition changes were monitored with bioelectrical analyzers as well as the traditional density and deuterium dilution techniques. Maintaining daily protein intakes at the prerestriction quantities did not affect lean body tissue losses nor body weight losses, 9.6 to 19.0kg/person for the study. Minimal changes in resting metabolic rates were consistent with minimal changes in lean body mass. The total body electrical conductivity instrument (TOBEC) 3 and the underwater weighing-density method yielded similar body composition changes during weight loss.

Energy restriction and immunocompetence in overweight women

Abstract The purpose of this study was to examine the effects of energy restriction on human immune functions and the mechanisms involved. Eight overweight (30–50%) women, 28–41 y, were fed a weight stabilization diet for 3 weeks; for the next 15 weeks their energy intake was reduced by 50%, while still providing adequate protein, vitamins and minerals. Indices of immune response were determined twice at the end of each metabolic period. Energy restriction caused a mean weight loss of 13.2 Kg, 25% decrease in NK cells numbers, and a 20–30 % decrease in their In vitro activity determined at different effector to target cell ratios (p In vitro secretion of IL1, IL2, and IL2R by peripheral blood mononuclear cells stimulated with LPS or PHA were not altered by energy restriction. There was a 38% increase in the concentration of serum cortisol associated with energy restriction (p=0.001), which may have lead to the decline in immune functions. Although, there were no obvious health risks to participants of this study, potentially they could be at increased risk for viral infections and tumor growth.