The role of phosphorus in postprandial energy expenditure of healthy male subjects

Abstract

Diet induced thermogenesis is the increase in postprandial energy expenditure above the basal metabolic rate divided by the energy content of the food consumed during the meal, and it is usually expressed as a percentage (Westerterp, 2004). Each macronutrient has a specific DIT range, with the proteins having the highest DIT (20-30percent of the energy content), following by the carbohydrates (5-15percent), and then the fats with the lowest DIT of (0-3percent) (Westerterp et al, 1999). Phosphorus availability is an important determinant of DIT, since it is needed for ATP production. Refined carbohydrates and high sugar foods in addition to high saturated and trans-fats containing foods, that are linked to an increased obesity risk are low in phosphorus. Whereas protein rich foods (like meats, fish, poultry and dairy products) in addition to plant based foods such as nuts, unrefined grains, and beans, which are all related to decreased risk of obesity, are high in phosphorus (Halton et al, 2004). Previous studies have been done to measure the impact of phosphorus supplementation on DIT after consuming either a high protein meal (Abdouni et al, 2018) or a high carbohydrates meal (Assaad et al, 2018), and both studies concluded that phosphorus does increase PEE. Thus, in line with the previous studies, the present study is conducted to measure the involvement of phosphorus on DIT and respiratory quotient (RQ) of healthy male subjects consuming a high saturated fat meal. This study is a double-blind, randomized, and placebo-controlled crossover clinical trial. Twelve healthy male subjects with an age range between 19 and 35 years and with a body mass index ranging from 19.2-34.6 Kg-m² were recruited through direct approach. They were asked to come to the testing room after an overnight fast at 8:00 am. Anthropometric measurements (weight and height) were taken, then a finger prick experiment was done to determine the HbA1c blood level using the DCA VANTAGE SIEMENS MACHINE, and urine was collected to determine creatinine concent