Abstract
Problem statement: A goal during weight loss is to reduce body fat while maintaining
body protein. We hypothesized that an increased dietary lysine: calorie might be beneficial during
periods of caloric restriction. Approach: Two experiments were conducted to determine if changing
the ratio of lysine: calories (lysine g/kg: Mcal ME/kg) while maintaining an ideal profile of amino
acids will change nitrogen metabolism and weight loss in obese mature dogs. Results: The results of
these experiments imply that if all essential amino acids are in adequate supply in the food, foods with
an optimal balance of nutrients can reduce muscle degradation during periods of caloric restriction.
Conclusion: Our optimum food for decreasing protein degradation was the food containing 3.0 lysine:
calorie. However, the present experiments were relatively short and these results may not be sustained
over longer periods of restriction.