The effect of phosphorus supplementation on the development of fatty liver induced by a low protein diet in rats -

Abstract

There has been an increasing bulk of literature addressing the effect of varying levels of dietary protein intake on weight changes, body composition, and disease risk. More recent studies showed the epigenetic effect of a protein-restricted diet on the long-term development of the metabolic syndrome. Inadequate dietary protein intake is also known to be associated with the development of protein energy malnutrition (PEM). Kwashiorkor is a major form of PEM that is distinctively associated with edema and nonalcoholic fatty liver disease (NAFLD). However, its etiology remains unclear. Epidemiological evidence has reported that Kwashiorkor is mostly prevalent in developing countries where the main staple foods include plant-based food items such as maize, rice, or cassava, which are known to be poor dietary sources of both protein and phosphorus. Furthermore, malnutrition is commonly associated with low total body phosphate. Therefore, inadequate dietary P intake may be an important factor in the etiology of Kwashiorkor. However, the independent effect of P on the outcomes associated with a low protein diet remains unclear. The purpose of this study is to dissect the exclusive role of varying concentrations of dietary P on weight gain, food intake, body composition, serum lipid profile, serum glucose, serum insulin levels, and liver fat content in rats maintained on a low protein diet for 9 weeks. Forty-nine Sprague-Dawley rats were randomly allocated to 5 groups and fed ad-libitum 5 iso-caloric diets that only varied in protein and P concentrations. The control group received a normal protein (20percent) from egg white, and normal P (0.3percent) diet, whereas the 4 other groups were maintained on low protein (10percent) diets with varying levels of P: 0.015percent, 0.056percent, 0.1percent, and 0.3percent. The rat weights and food intakes were measured twice per week for 9 weeks. The rats were then sacrificed, and their body composition, liver fat content, and plasma biomarkers were analyzed. The results showed the average food intake, weight gain, a