title: Short-term, high-fat diets lower circulating leptin concentrations in rats.
abstract: BACKGROUND
  Leptin is produced in proportion to body fat mass and can act on the brain to induce satiety and regulate adipose tissue mass; factors other than adipose tissue mass may influence circulating leptin concentrations.
  
  
  OBJECTIVE
  We explored the possibility that short-term, moderately high-fat diets induce weight gain by producing inappropriately low circulating leptin concentrations.
  
  
  METHODS
  Female Hooded Wistar rats were fed either a moderately high-fat diet or control diet. Body weight, energy intake, body composition, and fasting plasma leptin were compared after 4 and 14 wk of dietary treatment.
  
  
  RESULTS
  After 4 wk, abdominal fat mass was 38% greater in rats fed the high-fat diet than in those fed the control diet (P < 0.01). However, plasma leptin concentrations were 24% lower in animals fed the high-fat diet (P < 0.05), resulting in significantly lower plasma leptin concentrations per unit abdominal fat mass than in control animals (P < 0.005). From 4 to 14 wk, animals fed the high-fat diet gained twice as much weight and consumed 32 kJ/d more than controls (both P < 0.05). At 14 wk, plasma leptin concentrations per unit abdominal fat mass were 27% lower in rats fed the high-fat diet (P = 0.058) and there was a significant negative association between leptin concentrations per unit abdominal fat mass and body weight (r = 0.44, P < 0.05).
  
  
  CONCLUSIONS
  In the short term, a moderately high-fat diet is associated with lower than expected circulating leptin concentrations, which correlate with a higher body weight. A high-fat diet may therefore contribute to weight gain by reducing leptin secretion in adipose tissue.
authors.affiliation: University of Melbourne, Department of Medicine, Royal Melbourne Hospital, Parkville, Australia.
authors.forename: D A
authors.initials: DA
authors.lastname: Ainslie
authors.forename: J
authors.initials: J
authors.lastname: Proietto
authors.forename: B C
authors.initials: BC
authors.lastname: Fam
authors.forename: A W
authors.initials: AW
authors.lastname: Thorburn
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001835:Body Weight; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage* / Q000494:pharmacology; D004044:Dietary Proteins / Q000008:administration & dosage; D002149:Energy Intake; D005260:Female; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood*; D009765:Obesity / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D007328:Insulin; D020738:Leptin