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document
Effect of macronutrient composition of the diet on the regulation of lipolysis in adipose tissue at rest and during exercise : microdialysis study . The aim of the present study was to elucidate , using a microdialysis technique , whether modifications in the proportion of fat in the diet influence lipid mobilization from adipose tissue in situ . Nine healthy volunteers ( age , 23.4 +/- 0.2 years ; body mas index [ BMI ] , 23.5 +/- 1.6 kg/m ( 2 ) ) were fed , in random order , with a high-fat diet ( HFD ) ( 65 % of energy content fat , 15 % protein , 20 % carbohydrate ) or a high-carbohydrate diet ( HCD ) ( 70 % carbohydrate , 15 % protein , 15 % fat ) for 5 days , with a washout period of 10 days between the diets . Subjects were studied in the fasting state on the morning following days 4 and 5 of each diet . We measured the concentration of extracellular glycerol ( EGC ) in adipose tissue in response to ( 1 ) pharmacologic stimulation with isoprenaline ( 1 and 10 micromol/L ) in situ , ( 2 ) stimulation with intravenous infusion of epinephrine ( 0.0375 microg/min/kg body weight ) , and ( 3 ) submaximal aerobic exercise ( 50 % V*O2max , 60-minute duration ) . No effect of the diet composition was found in the increases of EGC in response to isoprenaline ( area under the curve [ AUC ] : HFD , 1,534 +/- 370 micromol/90 min ; HCD , 1,108 +/- 465 micromol/90 min ; not significant [ NS ] ) or epinephrine stimulations ( AUC : HFD , 190 +/- 92 micromol/30 min ; HCD , 251 +/- 298 micromol/30 min ; NS ) . The exercise-induced increase in EGC was higher during the HFD ( AUC : HFD , 1,641 +/- 181 micromol/60 min ; HCD , 963 +/- 156 micromol/60 min ; P < .05 ) and was associated with a higher exercise-induced response of norepinephrine ( P < .05 ) and epinephrine ( P =.056 ) and lower insulinemia during exercise . The results suggest that macronutrient composition of diet does not affect the beta-adrenergic responsiveness of adipose tissue to catecholamine action at rest . During exercise , the HFD promotes higher lipolysis in adipose tissue and this is associated with a higher catecholamine response and lower insulinemia .
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Intervention_Physical
macronutrient
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Intervention_Physical
fat in the diet
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Intervention_Other
high-fat diet ( HFD ) ( 65 % of energy content fat , 15 % protein , 20 % carbohydrate ) or a high-carbohydrate diet ( HCD ) ( 70 % carbohydrate , 15 % protein , 15 % fat ) for 5 days , with a washout period of 10 days between the diets .
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Intervention_Pharmacological
isoprenaline
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Intervention_Pharmacological
epinephrine
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Intervention_Physical
aerobic exercise
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Intervention_Physical
HFD
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Outcome_Other
regulation of lipolysis in adipose tissue
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Outcome_Other
lipid mobilization
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Outcome_Physical
concentration of extracellular glycerol ( EGC ) in adipose tissue
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Outcome_Physical
diet composition
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Outcome_Other
increases of EGC
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Outcome_Other
epinephrine stimulations
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Outcome_Other
exercise-induced increase in EGC was higher
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Outcome_Other
higher exercise-induced response
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Outcome_Other
insulinemia
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Outcome_Other
beta-adrenergic responsiveness of adipose tissue
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Participant_Condition
healthy volunteers (
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Participant_Age
age , 23.4 +/- 0.2 years
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Participant_Condition
; body mas index [ BMI ] , 23.5 +/- 1.6 kg/m ( 2 ) )