Food intake measured by an automated food-selection system: relationship to energy expenditure.
Measuring food intake in a laboratory usually involves limited food choices. An automated food-selection system with two vending machines containing a large variety of foods was used to measure food intake in 10 male volunteers (31 +/- 6 y, 69.2 +/- 7.1 kg, 18 +/- 7% fat, mean +/- SD) on a metabolic ward. The effect of carbohydrate, fat, and protein intakes on 24-h energy expenditure (24EE) and substrate oxidations was measured in a respiratory chamber during day 4 of weight maintenance and day 7 of ad libitum intake. Ad libitum intake resulted in a 7-d overfeeding of 6468 +/- 3824 kJ/d above weight-maintenance requirements, leading to a 2.3 +/- 1.2-kg gain. The 10,975 +/- 3774 kJ excess energy intake on day 7 of ad libitum intake caused a 1205 +/- 920 kJ/d increase in 24EE (delta 24EE = 0.17 x delta intake - 695; r = 0.71, P less than 0.02). Of the excess carbohydrate intake, 74% was oxidized (r = 0.86, P less than 0.001), whereas excess fat intake was not. Carbohydrate and protein stores are regulated whereas excess fat intake is channeled to fat stores.
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Clinical Diabetes and Nutrition Section, National Institutes of Diabetes, Digestive Diseases, and Kidney Diseases, National Institutes of Health, Phoenix, AZ 85016.
Alger
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Boyce
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Seagle
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Ferraro
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Fontvieille
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Ravussin
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D000328:Adult; D000704:Analysis of Variance; D001835:Body Weight; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D004435:Eating; D004734:Energy Metabolism; D005509:Food Dispensers, Automatic; D005518:Food Preferences; D006801:Humans; D008297:Male; D012044:Regression Analysis; D013997:Time Factors
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins