Long-term effect of altered nutrition induced by litter size manipulation and cross-fostering in suckling male rats on development of obesity risk and health complications

Abstract

We investigated the long-term effect of pre-weaning nutrition on positive and/or adverse regulation of obesity risk and health complications in male Sprague-Dawley rats. Two experimental models were used in the present work: (1) To induce postnatal over- or normal nutrition, the litter size was adjusted to 4 (small litters-SL) and to 10 pups (normal litters-NL) in the nest, (2) in suckling pups at day 10, we used cross-fostering to identify the effect of altered dietary environment on their future body fat regulation, food intake, blood pressure, and the duodenal and jejunal alkaline phosphatase activity. After weaning, these control (NL, SL) and cross-fostered (NL-SL, SL-NL) groups were exposed to standard laboratory diet. On day 50, the SL in comparison with NL rats became heavier and displayed enhanced adiposity accompanied by significantly increased systolic blood pressure (19%) and duodenal (16%) and jejunal (21%) alkaline phosphatase (AP) activity. The impact of pre-weaning over-nutrition of NL-SL pups was associated with long-lasting positive effect on obesity. In contrast, SL-NL rats submitted until weaning to the opposite normalized feeding condition on day 50 showed significantly decreased fat deposition (21%), systolic blood pressure (20%), and AP activity in duodenum and jejunum (14%). These results contribute to a better understanding of how early-acquired dietary habits determine the attenuation or prevention of obesity development in later life and can provide some benefit for optimizing the future dietary strategies in young and adult obese individuals.