Metabolic response to low- and very-low-calorie diets.
We compared the metabolic effects of 8-wk caloric restrictions with 330 or 780 kcal/d in two groups of eight obese hospitalized subjects; six control subjects were also studied. Loss of weight but not of adipose tissue was significantly greater on the 330-kcal/d diet. It is likely that dehydration rather than protein catabolism was responsible for additional loss of fat-free mass in the 330-kcal/d group because the nitrogen deficit was not excessive. The thermic response to food was blunted only in the 330-kcal/d group whereas resting oxygen uptake decreased by equal amounts in both groups. There was a decrease in 24-h urinary noradrenaline in the 330-kcal/d group but plasma fT4 was sustained when compared with the 780-kcal/d group; fT3 decreased significantly more quickly in the 330-kcal/d group. There was no correlation between plasma hormone levels and changes in oxygen uptake. Hunger scores were greater on the 780-kcal/d diet.
Davies
H J
HJ
Department of Medicine, University of Cambridge, UK.
Baird
I M
IM
Fowler
J
J
Mills
I H
IH
Baillie
J E
JE
Rattan
S
S
Howard
A N
AN
D000328:Adult; D001823:Body Composition; D001835:Body Weight; D002395:Catecholamines / Q000378:metabolism; D004038:Diet, Reducing; D002149:Energy Intake; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D006815:Hunger; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy / Q000378:metabolism*; D010101:Oxygen Consumption; D013963:Thyroid Hormones / Q000097:blood
D002395:Catecholamines; D013963:Thyroid Hormones