Protein requirements with very low calorie diets

Area of Science:

• Nutrition Science
• Obesity Research
• Metabolic Studies

Background:

• Dietary treatment for obesity aims for fat loss while preserving lean body mass.
• Severe calorie restriction can lead to significant nitrogen loss, impacting lean body mass.
• Understanding protein's role in weight loss diets is critical for patient health.

Purpose of the Study:

• To compare the effects of two different dietary protein levels on nitrogen balance in obese women.
• To determine optimal protein intake for preserving lean body mass during severe calorie restriction.
• To evaluate the compatibility of recommended dietary allowances for protein with severe energy restriction.

Main Methods:

• A controlled study involving 17 obese women on a 500-calorie weight reduction diet.
• Two groups were assigned different protein intake levels: 0.8 g/kg and 1.5 g/kg.
• Nitrogen balance was measured after a three-week adaptation period.

Main Results:

• The group receiving 0.8 g/kg protein had a nitrogen balance of -2 grams.
• The group receiving 1.5 g/kg protein achieved zero nitrogen balance.
• Lower protein intake (0.8 g/kg) was insufficient for nitrogen equilibrium in severely restricted diets.

Conclusions:

• Recommended dietary allowances for protein (0.8 g/kg) are inadequate for maintaining nitrogen balance during severe calorie restriction.
• Higher protein intake (1.5 g/kg) is necessary to achieve nitrogen equilibrium in obese individuals on very low-calorie diets.
• Assessing the composition of weight loss (fat, protein, water) is essential for effective obesity treatment.