Effect of weight loss by a low-fat diet and a low-carbohydrate diet on peptide YY levels.
OBJECTIVE
To compare the effects of weight loss by an energy-restricted low-fat diet vs low-carbohydrate diet on serum peptide YY (PYY) levels.


METHODS
8-Week prospective study of 30 obese adults (mean age: 42.8+/-2.0 years, mean body mass index 35.5+/-0.6 kg m(-2)).


RESULTS
After 8 weeks, subjects on the low-carbohydrate diet lost substantially more weight than those on the low-fat diet (5.8 vs 0.99 kg, P<0.001). Weight loss by either diet resulted in a 9% reduction in both mean fasting serum PYY levels (baseline: 103.5+/-8.8 pg ml(-1), after weight loss: 94.1+/-6.5 pg ml(-1), P<0.01) and postprandial area under the curve (AUC) PYY (baseline: (20.5+/-1.5) x 10(3) pg h(-1) ml(-1), after weight loss: mean AUC PYY (18.8+/-1.4) x 10(3) pg h(-1) ml(-1), P<0.001). There was a trend towards lower levels of PYY with greater degrees of weight loss.


CONCLUSIONS
Reduced PYY levels after weight loss by an energy-restricted low-fat or low-carbohydrate diet likely represents a compensatory response to maintain energy homeostasis and contributes to difficulty in weight loss during energy-restricted diets.
Essah
P A
PA
Department of Internal Medicine, Virginia Commonwealth, University School of Medicine, Richmond, VA 23298-0111, USA. pessah@mcvh-vcu.edu
Levy
J R
JR
Sistrun
S N
SN
Kelly
S M
SM
Nestler
J E
JE
D000328:Adult; D015992:Body Mass Index; D050528:Diet, Carbohydrate-Restricted; D018752:Diet, Fat-Restricted; D004038:Diet, Reducing; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000097:blood* / Q000503:physiopathology; D019894:Peptide YY / Q000097:blood*; D019518:Postprandial Period; D011446:Prospective Studies; D015431:Weight Loss / Q000502:physiology*
D019894:Peptide YY