King Grub
2016-11-09, 13:02
CONTEXT:
In humans, dietary versus intra-individual determinants of macronutrient oxidation preference and the role of the sympathetic nervous system (SNS) during short-term overfeeding and fasting are unclear.
OBJECTIVE:
To understand the influence of diet and the SNS during 24-h of overfeeding on metabolic changes.
DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS:
While residing on a clinical research unit, 64 participants with normal glucose regulation were assessed during energy balance, fasting, and four 24-h overfeeding diets, given in random order. The overfeeding diets contained 200% of energy requirements and varied macronutrient proportions: 1) standard (50% carbohydrate, 20% protein, and 30% fat), 2) 75% carbohydrate, 3) 60% fat, and 4) 3% protein.
MAIN OUTCOME MEASURES:
24-hour energy expenditure (EE) and macronutrient oxidation rates were measured in an indirect calorimeter during the dietary interventions, with concomitant measurement of urinary catecholamines and free cortisol.
RESULTS:
EE decreased with fasting (-7.7±4.8%, p<0.0001) and increased with overfeeding. The smallest increase occurred during the diet with 3% protein (2.7±4.5%, p=0.001) and the greatest during the diet with 75% carbohydrate (13.8±5.7%, p<0.0001). Approximately 60% of macronutrient oxidation was determined by diet and 20% by intrinsic factors (p<0.0001). Only urinary epinephrine differed between fasting and overfeeding diets (Δ=2.25±2.9 µg/24h, p<0.0001). During fasting, higher urinary epinephrine concentrations correlated with smaller reductions in EE (ρ=0.34, p=0.01).
CONCLUSIONS:
Independent from dietary macronutrient proportions, there is a strong individual contribution to fuel preference that remains consistent across diets. Higher urinary epinephrine may reflect the importance of epinephrine in maintaining EE during fasting.
J Clin Endocrinol Metab. 2016 Nov 7:jc20163006. The Consistency in Macronutrient Oxidation and The Role for Epinephrine in the Response to Fasting and Overfeeding.
http://press.endocrine.org/doi/10.1210/jc.2016-3006?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed
In humans, dietary versus intra-individual determinants of macronutrient oxidation preference and the role of the sympathetic nervous system (SNS) during short-term overfeeding and fasting are unclear.
OBJECTIVE:
To understand the influence of diet and the SNS during 24-h of overfeeding on metabolic changes.
DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS:
While residing on a clinical research unit, 64 participants with normal glucose regulation were assessed during energy balance, fasting, and four 24-h overfeeding diets, given in random order. The overfeeding diets contained 200% of energy requirements and varied macronutrient proportions: 1) standard (50% carbohydrate, 20% protein, and 30% fat), 2) 75% carbohydrate, 3) 60% fat, and 4) 3% protein.
MAIN OUTCOME MEASURES:
24-hour energy expenditure (EE) and macronutrient oxidation rates were measured in an indirect calorimeter during the dietary interventions, with concomitant measurement of urinary catecholamines and free cortisol.
RESULTS:
EE decreased with fasting (-7.7±4.8%, p<0.0001) and increased with overfeeding. The smallest increase occurred during the diet with 3% protein (2.7±4.5%, p=0.001) and the greatest during the diet with 75% carbohydrate (13.8±5.7%, p<0.0001). Approximately 60% of macronutrient oxidation was determined by diet and 20% by intrinsic factors (p<0.0001). Only urinary epinephrine differed between fasting and overfeeding diets (Δ=2.25±2.9 µg/24h, p<0.0001). During fasting, higher urinary epinephrine concentrations correlated with smaller reductions in EE (ρ=0.34, p=0.01).
CONCLUSIONS:
Independent from dietary macronutrient proportions, there is a strong individual contribution to fuel preference that remains consistent across diets. Higher urinary epinephrine may reflect the importance of epinephrine in maintaining EE during fasting.
J Clin Endocrinol Metab. 2016 Nov 7:jc20163006. The Consistency in Macronutrient Oxidation and The Role for Epinephrine in the Response to Fasting and Overfeeding.
http://press.endocrine.org/doi/10.1210/jc.2016-3006?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed