PA. Essah, JR. Levy, SN. Sistrun, SM. Kelly and JE. Nestler (2010). Effect of weight loss by a low-fat diet and a low-carbohydrate diet on peptide YY levels. International journal of obesity (2005), 34(8), 1239-42. https://doi.org/10.1038/ijo.2010.48

PubMed 20351741

[Abstract]
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.