title: A comparison of effects of lard and hydrogenated vegetable shortening on the development of high-fat diet-induced obesity in rats.
abstract: BACKGROUND
  Obesity is associated with increased consumption and preference for dietary fat. Experimental models of fat-induced obesity use either lard or vegetable shortening. Yet, there are no direct comparisons of these commonly used fat sources, or the influence of their fatty acid composition, on the development of diet-induced obesity.
  
  
  OBJECTIVE
  To compare the effects of lard and hydrogenated vegetable-shortening diets, which differ in their fatty acid composition, on weight gain and the development of obesity and insulin resistance in rats.
  
  
  METHODS
  Male Wistar rats were fed ad libitum for 14 weeks high-fat diets containing either (1) high vegetable fat (HVF, 60 kcal% from vegetable shortening) or (2) high lard fat (HLF, 60 kcal% from lard). Rats fed normal-fat (NF, 16 kcal% from vegetable shortening) diet served as control. Body weight, food intake, adipose tissue mass, serum 25[OH]D3, glucose, insulin and fatty acid composition of diets were measured.
  
  
  RESULTS
  Rats fed either of the two high-fat diets had higher energy intake, weight gain and fat accretion than rats fed normal-fat diet. However, rats fed the HLF diet consumed more calories and gained more weight and body fat with greater increases of 32% in total (158.5±8.2 vs 120.2±6.6 g, P<0.05), 30% in visceral (104.4±5.2 vs 80.3±4.2 g, P<0.05) and 36% in subcutaneous fat mass (54.1±3.6 vs 39.9±3.1 g, P<0.05), compared with rats fed the HVF diet. Higher visceral adiposity was positively correlated with serum insulin (r=0.376, P<0.05) and homeostatic model assessment insulin resistance (r=0.391, P<0.05).
  
  
  CONCLUSIONS
  We conclude that lard-based high-fat diets accentuate the increase in weight gain and the development of obesity and insulin resistance more than hydrogenated vegetable-shortening diets. These results further point to the importance of standardizing fatty acid composition and type of fat used in determining outcomes of consuming high-fat diets.
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Kubant
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: A N
authors.initials: AN
authors.lastname: Poon
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Sánchez-Hernández
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: A F
authors.initials: AF
authors.lastname: Domenichiello
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: P S P
authors.initials: PS
authors.lastname: Huot
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: E
authors.initials: E
authors.lastname: Pannia
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: C E
authors.initials: CE
authors.lastname: Cho
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Hunschede
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: R P
authors.initials: RP
authors.lastname: Bazinet
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.|Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: G H
authors.initials: GH
authors.lastname: Anderson