RESUMO
OBJECTIVES: Protein-energy wasting is a risk factor for mortality and morbidity in hemodialysis patients (HD patients). Food intake could be modified by HD-related changes in the food reward system (i.e., liking and wanting of specific macronutrients). In HD patients on days with and without dialysis, we evaluated (1) the reward system for protein-, fat-, and carbohydrate-rich foods, plasma hormones, and metabolite changes; and (2) the spontaneous ad libitum intake of macronutrients. (DESIGN AND) METHODS: Twenty-four HD patients evaluated their liking and wanting of macronutrients at 7:30 AM and 11:30 AM on a day with and a day without dialysis. Concentrations of hormones and plasma amino acids were determined. An additional 18 HD patients ate what they wanted from a buffet lunch comprising 8 dishes on a day with and a day without dialysis. Healthy subjects, age-, sex-, and body mass index-matched, served as controls. RESULTS: At 11:30 AM, wanting for protein-rich foods was higher on the day with than on the day without dialysis (P < .01), bringing wanting levels close to those of healthy subjects. This increase correlated with changes in the concentrations of plasma amino acids (P < .01). HD patients ate more protein from the buffet on the day with than on the day without dialysis (P < .01) and more than healthy subjects (P < .01). CONCLUSIONS: In HD patients, wanting and spontaneous intake of protein-rich foods increase immediately after dialysis. This increase correlated with decreased concentrations of plasma amino acids. Thus, in clinical practice, protein-rich foods should be recommended during and after dialysis in patients with protein-energy wasting.
