The effects of a low-carbohydrate diet on appetite: A randomized controlled trial

Nutr Metab Cardiovasc Dis. 2016 Jun;26(6):476-88. doi: 10.1016/j.numecd.2015.11.011. Epub 2015 Dec 12.


Background and aims: The relationship between dietary macronutrient composition and appetite is controversial. We examined the effects of a year-long low-carbohydrate diet compared to a low-fat diet on appetite-related hormones and self-reported change in appetite.

Methods and results: A total of 148 adults with a body mass index 30-45 kg/m(2), who were free of diabetes, cardiovascular disease and chronic kidney disease at baseline were randomly assigned to either a low-carbohydrate diet (carbohydrate [excluding dietary fiber]<40 g/day; N = 75) or a low-fat diet (<30% energy from fat, <7% from saturated fat; N = 73). Participants in both groups attended individual and group dietary counseling sessions where they were provided the same behavioral curriculum and advised to maintain baseline levels of physical activity. Appetite and appetite-related hormones were measured at 0, 3, 6 and 12 months of intervention. At 12 months, mean changes (95% CI) in peptide YY were -34.8 pg/mL (-41.0 to -28.6) and in the low-carbohydrate group and -44.2 pg/mL (-50.4 to -38.0) in the low-fat group (net change: 9.54 pg/mL [0.6 to 18.2]; p = 0.036). Approximately 99% of dietary effects on peptide YY are explained by differences in dietary macronutrient content. There was no difference in change in ghrelin or self-reported change in appetite between the groups.

Conclusions: A low-fat diet reduced peptide YY more than a low-carbohydrate diet. These findings suggest that satiety may be better preserved on a low-carbohydrate diet, as compared to a low fat diet.

Trial registration: Identifier: NCT00609271.

Keywords: Appetite; Clinical trial; Ghrelin; Low-carbohydrate diet; Peptide YY.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Appetite Regulation*
  • Biomarkers / blood
  • Counseling
  • Diet, Carbohydrate-Restricted*
  • Diet, Fat-Restricted*
  • Exercise
  • Female
  • Ghrelin / blood
  • Humans
  • Male
  • Middle Aged
  • New Orleans
  • Obesity / diagnosis
  • Obesity / diet therapy*
  • Obesity / physiopathology
  • Obesity / psychology
  • Peptide YY / blood
  • Satiation*
  • Time Factors
  • Treatment Outcome
  • Weight Loss*
  • Young Adult


  • Biomarkers
  • GHRL protein, human
  • Ghrelin
  • Peptide YY

Associated data