Effect of weight loss by a low-fat diet and a low-carbohydrate diet on peptide YY levels

Int J Obes (Lond). 2010 Aug;34(8):1239-42. doi: 10.1038/ijo.2010.48. Epub 2010 Mar 30.


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.

Design: 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.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Body Mass Index
  • Diet, Carbohydrate-Restricted*
  • Diet, Fat-Restricted*
  • Diet, Reducing
  • Female
  • Humans
  • Male
  • Obesity / blood*
  • Obesity / physiopathology
  • Peptide YY / blood*
  • Postprandial Period
  • Prospective Studies
  • Weight Loss / physiology*


  • Peptide YY