Indian rat strain solves obesity puzzle
doi:10.1038/nindia.2017.108 Published online 24 August 2017
A strain of rat that is obesogenic (has potential to become obese), maintained at the National Centre for Laboratory Animal Sciences in Hyderabad, has helped researchers find out why some people become fat and others do not, while eating the same calorie rich diet. The study has shown that genotype of an individual — and not excessive diet alone — determines one's tendency to become obese1.
The researchers addressed this problem by selecting the obesogenic strain called WNIN and two other rat strains with different genetic backgrounds. They were fed on similar high calorie diets for 13 weeks and assessed for physical, metabolic, biochemical, inflammatory responses, and gene expression. The two other strains showed no weight gain.
WNIN rats showed significantly increased energy consumption and decreased energy expenditure resulting in increased body weight gain. This showed that certain genotypes are more prone to obesity than others.
The authors say the study "indicates that certain genotypes undergo epigenetic modifications at protein or gene promoter levels when interacting with nutritional factors thus underlining the cumulative role of genetics and diet towards the development of obesity".
The finding they say "is critical for understanding obesity and devising new strategies to control and manage this epidemic."
1. Muralidhar M. N. et al. Differential response of rat strains to obesogenic diets underlines the importance of genetic makeup of an individual towards obesity. Sci. Rep. 7 (2017) doi: 10.1038/s41598-017-09149-6