QTLs influencing carbohydrate and fat choice in a LOU/CxFischer 344 F2 rat population.

Objective: Individual differences in macronutrient selection, particularly fat and carbohydrate, and associated body weight gain are partly inherited as polygenic traits, but the potential genetic pathways are unknown. To give an overview of the Quantitative Trait Loci (QTLs) and candidate gene pathways influencing these differences in rat was aimed in this study.

Design And Methods: To that end, F2 rats obtained from the crossbreeding between LOU/C and Fischer 344 rat strains to diet self-selection during 3 weeks were submitted.

Lactose malabsorption and colonic fermentations alter host metabolism in rats.

Lactose malabsorption is associated with rapid production of high levels of osmotic compounds, such as organic acids and SCFA in the colon, suspected to contribute to the onset of lactose intolerance. Adult rats are lactase deficient and the present study was conducted to evaluate in vivo the metabolic consequences of acute lactose ingestion, including host-microbiota interactions. Rats received diets of 25% sucrose (S25 control group) or 25% lactose (L25 experimental group).

Acute stress modifies food choice in Wistar male and female rats.

The present study investigates the effects of acute stress (15 min of swimming/day for three consecutive days) applied at the onset of the dark phase, just before the usual feeding time, on energy intake and more specifically on macronutrient selection, in male and female Wistar rats. The influence of stress regarding corticosterone and insulin kinetics was also examined. In the two experiments (1: food ad lib and 2: two feeding periods/day), three consecutive days of stress reduced daily body weight gain for both sexes.

C57BL/6J and A/J mice fed a high-fat diet delineate components of metabolic syndrome.

Objective: The aim of this study was to assess the suitability of A/J and C57BL/6J mice of both sexes as models of some components of the human metabolic syndrome (MetS) under nutritional conditions more comparable with the actual worldwide diet responsible for the increased incidence of the MetS.

Research Methods: We fed large cohorts (n = 515) of two strains of mice, A/J and the C57BL/6J, and of both sexes a high-fat diet (HFD; 60% fat) that, in contrast with most previous reports using saturated fats, was enriched in mono- and polyunsaturated fatty acids, thus more closely mimicking most Western diets, or a control diet (10% fat), for 20 weeks.

Results: In sharp contrast to previous reports, weight gain and hyperleptinemia were similar in both strains and sexes.

Comparison of energy balance in two inbred strains of rats: Fischer F344 prone to obesity and Lou rats resistant to obesity.

This study aimed to compare energy balance, metabolic profiles and body composition between two inbred strains of rats (F344 and Lou) submitted to a self-selecting macronutrient. During the 3 weeks of experiment, the two strains did not differ significantly for their total energy intake; males: F344 = 5875.4 +/- 171.