TY - JOUR
T1 - Dietary protein and urinary nitrogen in relation to 6-year changes in fat mass and fat-free mass
AU - Ankarfeldt, Mikkel Zøllner
AU - Gottliebsen, K
AU - Ängquist, L
AU - Astrup, Arne
AU - Heitmann, B L
AU - Sørensen, Thorkild I.A.
N1 - CURIS 2015 NEXS 023
PY - 2015
Y1 - 2015
N2 - Background:In contrast to the physiological expectation, observational studies show that greater protein intake is associated with subsequent body weight (BW) gain. An increase in fat-free mass (FFM) due to anabolic effects of protein could explain this.Objective:To examine associations between protein intake and subsequent changes in fat mass (FM) and FFM in longitudinal, observational data.Design:A health examination, including measures of FM and FFM by bioelectrical impedance at baseline and follow-up six years later, was conducted. Diet history interviews (DHI) were performed, and 24-hour urinary nitrogen collection at baseline was done. In total, 330 participants with DHI, of whom 227 had validated and complete 24-hour urine collection, were analyzed. Macronutrient energy substitution models were used.Results:Mean estimated protein intake was 14.6 E% from DHI and 11.3 E% from urinary nitrogen. Estimated from DHI, FM increased 46 gram/year with every 1 E% protein substituted for fat (95%CI: 13, 79; P=0.006) and FFM increased 15 gram/year (1, 30; P=0.046). Results were similar in other substitution models. Estimated from urinary nitrogen, FM increased 53 gram/year with 1 E% protein substituted for other macronutrients (24, 81; p<0.0005), and FFM increased 18 gram/year (6, 31; P=0.004).Conclusion:Within a habitual range, a greater protein intake was associated with BW gain, mostly in FM. This is in contrast to the expectations based on physiological and clinical trials, and calls for a better understanding of how habitual dietary protein influences long-term energy balance, versus how greater changes in dietary proteins may influence short-term energy balance.International Journal of Obesity accepted article preview online, 20 May 2014; doi:10.1038/ijo.2014.80.
AB - Background:In contrast to the physiological expectation, observational studies show that greater protein intake is associated with subsequent body weight (BW) gain. An increase in fat-free mass (FFM) due to anabolic effects of protein could explain this.Objective:To examine associations between protein intake and subsequent changes in fat mass (FM) and FFM in longitudinal, observational data.Design:A health examination, including measures of FM and FFM by bioelectrical impedance at baseline and follow-up six years later, was conducted. Diet history interviews (DHI) were performed, and 24-hour urinary nitrogen collection at baseline was done. In total, 330 participants with DHI, of whom 227 had validated and complete 24-hour urine collection, were analyzed. Macronutrient energy substitution models were used.Results:Mean estimated protein intake was 14.6 E% from DHI and 11.3 E% from urinary nitrogen. Estimated from DHI, FM increased 46 gram/year with every 1 E% protein substituted for fat (95%CI: 13, 79; P=0.006) and FFM increased 15 gram/year (1, 30; P=0.046). Results were similar in other substitution models. Estimated from urinary nitrogen, FM increased 53 gram/year with 1 E% protein substituted for other macronutrients (24, 81; p<0.0005), and FFM increased 18 gram/year (6, 31; P=0.004).Conclusion:Within a habitual range, a greater protein intake was associated with BW gain, mostly in FM. This is in contrast to the expectations based on physiological and clinical trials, and calls for a better understanding of how habitual dietary protein influences long-term energy balance, versus how greater changes in dietary proteins may influence short-term energy balance.International Journal of Obesity accepted article preview online, 20 May 2014; doi:10.1038/ijo.2014.80.
U2 - 10.1038/ijo.2014.80
DO - 10.1038/ijo.2014.80
M3 - Journal article
C2 - 24840082
VL - 39
SP - 162
EP - 168
JO - International Journal of Obesity
JF - International Journal of Obesity
SN - 0307-0565
IS - 1
ER -