Phosphorus supplementation increases thermic response to glucose solution in healthy lean subjects

Abstract

Thermic effect of food (TEF) is believed to be largely related to ATP production that is known to depend on phosphorus (P) availability. We hypothesised that the addition of P to a glucose load would enhance ATP production resulting in an increase in TEF. To test this hypothesis, we measured the TEF of glucose solution with or without P in seven healthy subjects (3M 4F; Age=21.1±0.8y; BMI= 23.2 ±1.3kg/m2) in a cross over design with 1 week washout period. After a 10-h overnight fast, subjects drank a standardized 296mL solution containing 75g glucose, with P (500mg) or placebo pills. Oxygen consumption (VO2) was measured every 30 min for 3 hours. Baseline fasting resting metabolic rate (RMR) and VO2 did not differ between the 2 studies (1.2±0.2kcal/min and 250±37mL/min, respectively; p=0.92). Addition of P was associated with higher increase in VO2 (959±315 vs. 534±274 mL/60min; p= 0.03) which corresponded to higher TEF (5.7±1.6 vs. 3.6and±1.3kcal/60min; p=0.03 equivalent to 8% vs. 5% increase from RMR) during the first 60 min. VO2 and TEF did not differ between the studies afterwards. In conclusion, postprandial energy expenditure was further stimulated after drinking glucose solution with than without P. These results highlight the role of P in energy expenditure and thus energy balance.