Influence of diet composition on intake and utilization of protein and energy in diabetic and control rats

Influence of diet composition on intakes of protein (PI) and metabolizable energy (MEI) of male Sprague-Dawley diabetic and control rats was studied to identify diet compositions appropriate for either weight maintenance or growth. Twenty-five diets containing varying proportions of gross energy derived from protein (% P), fat (% F) and carbohydrate (% C) were fed ad libitum to diabetic and control rats for 21 d. Regardless of diet composition, diabetic rats had greater PI and MEI than their corresponding controls. MEI of both diabetic and control rats were affected by an increase in % P, while that of the control rats, only by an increase in % F. When compared to the controls, diabetic rats lost less body weight at 2.25 % P, gained less at 11.1, 22.2 or 33.3 % P, and did not differ at 5.5 % P, the level at which both groups nearly maintained their body weights. Protein and energetic efficiency for diabetic and control rats were maximal at 11.1 % P. This study showed that, for adult diabetic and control rats, 5.5 % P was adequate for maintenance. For growth, 11.1 % P was optimal for diabetic rats compared with 22.2 % P for the controls. For both the groups, 22.2 % F or lower was preferable.