Calorie for Calorie, Dietary Fat Restriction Results in More Body Fat Loss than Carbohydrate Restriction in People with Obesity.
Dietary carbohydrate restriction has been purported to cause endocrine adaptations that promote body fat loss more than dietary fat restriction. We selectively restricted dietary carbohydrate versus fat for 6 days following a 5-day baseline diet in 19 adults with obesity confined to a metabolic ward where they exercised daily. Subjects received both isocaloric diets in random order during each of two inpatient stays. Body fat loss was calculated as the difference between daily fat intake and net fat oxidation measured while residing in a metabolic chamber. Whereas carbohydrate restriction led to sustained increases in fat oxidation and loss of 53 ± 6 g/day of body fat, fat oxidation was unchanged by fat restriction, leading to 89 ± 6 g/day of fat loss, and was significantly greater than carbohydrate restriction (p = 0.002). Mathematical model simulations agreed with these data, but predicted that the body acts to minimize body fat differences with prolonged isocaloric diets varying in carbohydrate and fat.
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: kevinh@niddk.nih.gov.
Kevin D
KD
Hall
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Thomas
T
Bemis
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Robert
R
Brychta
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Kong Y
KY
Chen
Clinical Center Nutrition Department, National Institutes of Health, Bethesda, MD 20892, USA.
Amber
A
Courville
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Emma J
EJ
Crayner
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Stephanie
S
Goodwin
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Juen
J
Guo
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Lilian
L
Howard
Towson University, Towson, MD 21252, USA.
Nicolas D
ND
Knuth
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Bernard V
BV
Miller
University of Alberta, Edmonton, AB T6G 2R3, Canada.
Carla M
CM
Prado
Newcastle University, Newcastle upon Tyne NE4 5PL, UK.
Mario
M
Siervo
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Monica C
MC
Skarulis
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Mary
M
Walter
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Peter J
PJ
Walter
National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Laura
L
Yannai
D000273:Adipose Tissue / Q000378:metabolism / Q000473:pathology; D000328:Adult; D050528:Diet, Carbohydrate-Restricted; D018752:Diet, Fat-Restricted; D004038:Diet, Reducing; D004040:Dietary Carbohydrates / Q000378:metabolism; D004041:Dietary Fats / Q000378:metabolism; D002149:Energy Intake; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D009765:Obesity / Q000178:diet therapy* / Q000378:metabolism / Q000473:pathology; D010084:Oxidation-Reduction
D004040:Dietary Carbohydrates; D004041:Dietary Fats