Is obesity linked to our genes?

9 April 2021

Is obesity linked to our genes?

Photo credit: ID: 83822327, Vchalup,

Many factors have been given for influencing body weight in humans. These include the built environment, medical conditions, human behavior, medications, but increasingly there is a strong association of a genetic role in obesity. In a landmark study, Stunkard et al 1986 found that there was a correlation between the weight of Danish adoptees and the body mass index (BMI) of their biological parents that was statistically significant, particularly for their mothers. Furthermore, he found that there was no correlation between the weight of adoptees and their adoptive parents and that this was applicable across all weight classes, not just the obese adoptees, but also those who were thin. (Stunkard et al, 1986)

Mutations in genes alone, which occur slowly, cannot explain the obesity epidemic that has occurred in the past few decades around the world. It Australia, there has been a 11.3% rise in the prevalence of obesity in Australia from 1980 to 2000 which is 2.5 times increase, over 20 years. (Cameron et al, 2003) Interest is growing in the role of the environment and the gene-environment interaction in the increase prevalence of obesity and obesity related comorbidities. Epigenetics the activation or deactivation of gene expression across certain tissues without DNA sequence changes to the genome. It is thought that through this mechanism, environmental chemicals, gut microbiota modifications and poor nutritional intake can have an impact on metabolism and contribute to obesity and its comorbidities. (Thaker VV, 2017).

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Stunkard, AJ, Sørensen, TI, Hanis, C, Teasdale, TW, Chakraborty, R, Schull, WJ, & Schulsinger, F, 1986, ‘An adoption study of human obesity’, The New England journal of medicine, 314(4): 193–198.

Cameron, AJ, Zimmet, PZ, Dunstan, DW, Dalton M, Shaw, JE, Welborn, TA, Owen, N, Salmon, J & Jolley, D, 2003, ‘Overweight and obesity in Australia: the 1999-2000 Australian Diabetes, Obesity and Lifestyle Study (AusDiab)’, Medical Journal of Australia, 178 (9): 427- 432.

Thaker V. V. (2017). ‘Genetic and epigenetic causes of obesity’ Adolescent medicine: state of the art reviews,28(2), 379–405.