tjing
2013-06-03, 22:06
Extent and determinants of thermogenic responses to 24 hours of fasting, energy balance, and five different overfeeding diets in humans.
Abstract:
Context:Individual variation in the ability to convert excess calories to heat and the effects of dietary macronutrient composition are unclear.Objective:Stability and determinants of the energy expenditure (EE) response to overconsumption were assessed.
Design, Setting, and Participants:Twenty subjects (75% male) with normal glucose regulation were evaluated during 24 hours each of energy balance, fasting, and five different diets with 200% energy requirements in a clinical research unit.
Interventions:Five 1-day overfeeding diets were given in random order: high carbohydrate (75%), low protein (3%); high carbohydrate, normal protein (20%); high fat (46%), low protein; high fat (60%), normal protein; and balanced (50% carbohydrates, 20% protein).Main Outcome Measures:The 24h-EE, sleeping EE, and thermic effect of food (TEF) during each diet were measured with a metabolic chamber. Appetitive hormones were measured before and after the diets.Results:The EE response to overfeeding exhibited good intraindividual reproducibility. Similar increases above eucaloric feeding in 24h-EE (mean: 10.7±5.7%, p<0.001; range: 2.9-18.8%) and sleeping EE (14.4±11.3%, p<0.001; range: 1.0-45.1%) occurred when overfeeding diets containing 20% protein, despite differences in fat and carbohydrate content, but the EE response during overfeeding diets containing 3% protein was attenuated. Percent body fat negatively correlated with TEF during normal protein overfeeding (r=-0.53, p<0.01). Fasting peptide YY negatively correlated with TEF (r=-0.56, p<0.01) and the increase in sleeping EE (r=-0.54, p<0.01) during overfeeding.
Conclusions:There is an intrinsic EE response to overfeeding that negatively associates with adiposity, although it represents a small percentage of consumed calories.
http://www.ncbi.nlm.nih.gov/pubmed/23666976
J Clin Endocrinol Metab. 2013 May 10.
Abstract:
Context:Individual variation in the ability to convert excess calories to heat and the effects of dietary macronutrient composition are unclear.Objective:Stability and determinants of the energy expenditure (EE) response to overconsumption were assessed.
Design, Setting, and Participants:Twenty subjects (75% male) with normal glucose regulation were evaluated during 24 hours each of energy balance, fasting, and five different diets with 200% energy requirements in a clinical research unit.
Interventions:Five 1-day overfeeding diets were given in random order: high carbohydrate (75%), low protein (3%); high carbohydrate, normal protein (20%); high fat (46%), low protein; high fat (60%), normal protein; and balanced (50% carbohydrates, 20% protein).Main Outcome Measures:The 24h-EE, sleeping EE, and thermic effect of food (TEF) during each diet were measured with a metabolic chamber. Appetitive hormones were measured before and after the diets.Results:The EE response to overfeeding exhibited good intraindividual reproducibility. Similar increases above eucaloric feeding in 24h-EE (mean: 10.7±5.7%, p<0.001; range: 2.9-18.8%) and sleeping EE (14.4±11.3%, p<0.001; range: 1.0-45.1%) occurred when overfeeding diets containing 20% protein, despite differences in fat and carbohydrate content, but the EE response during overfeeding diets containing 3% protein was attenuated. Percent body fat negatively correlated with TEF during normal protein overfeeding (r=-0.53, p<0.01). Fasting peptide YY negatively correlated with TEF (r=-0.56, p<0.01) and the increase in sleeping EE (r=-0.54, p<0.01) during overfeeding.
Conclusions:There is an intrinsic EE response to overfeeding that negatively associates with adiposity, although it represents a small percentage of consumed calories.
http://www.ncbi.nlm.nih.gov/pubmed/23666976
J Clin Endocrinol Metab. 2013 May 10.