Obesity Causes Genetics

Obesity in genes may predispose some people to excess weight gain. Although the exact relationship between genetics and obesity is unclear, many researchers agree that a predisposition to obesity could be part of a person’s genetic makeup. Other inherited factors related to obesity could determine metabolic rates and how the body processes food. Studies on obesity genetics continue to indicate that heredity can contribute to obesity.

Statistics compiled by the World Health Organization (WHO) (2006) indicate an increase in worldwide obesity. In 2005, 400 million adults met the criteria for obesity. By 2015, however, the WHO predicts this number will rise to 700 million people.

Two main contributing obesity factors are the ready availability of high-calorie food and a general lack of exercise. However, people of all shapes and sizes enjoy similar lifestyles, suggesting the possibility of genetic obesity causes.

Obesity and Genetics

Obesity and Genes

Genetics can affect obesity in many ways. Factors influenced by obesity in genes may include appetite level and sense of fullness, calories burned during exericse and calories burned during rest.

Genetics may also affect how the body handles excess fat and where this fat is stored. Even on low-calorie diets, some people have trouble losing or maintaining weight. Others go through vigorous exercise programs with slower-than-normal results. Genetic obesity predispositions may explain why some people struggle to maintain a healthy weight.

Obesity Genetics and Family Dynamics

Obesity genetics cannot be singled out as the only cause of obesity. While it’s true that genetics can indicate a predisposition to obesity, environment and lifestyle also play a large role in a person’s health. Parents who overeat and avoid exercise are likely to pass those habits on to their children.

On the other hand, studies conducted in adoptee households confirm the link between genetics and obesity. Upon reaching adulthood, adopted children tend to reflect the bodily features of their birth parents. Identical twins who have been raised apart also reflect these same patterns, suggesting a strong presence of obesity in genes.

Studies on Obesity and Genes

Studies continue to link gene mutations with obesity. For instance, some individuals are morbidly obese from infancy. Although these situations are rare, they may be a broad indicator of genetic obesity. Genetic defects in leptin, a hormone responsible for regulating appetite, and the appetite-controlling enzyme PCI have been suggested as genetic causes of obesity.

Research based on the “thrifty gene” hypothesis is frequently cited in quotes on genetics and obesity. First proposed in 1962, geneticist James Neel’s “thrifty gene” hypothesis suggests that the human body follows an ancestral pattern of “feast or famine.” Fat is stored when food is plentiful in preparation for leaner times. In today’s society, the feast continues without the famine, leading to weight gain.

Fighting the Link Between Obesity and Genes

Even as much as a 10 percent weight loss can provide immense health benefits. Genes play a part in how fast and how easily that weight is lost. Genetics influence the weight maintenance battle for many once the pounds are gone. While genes influence a person’s weight level, proper nutrition and exercise are often enough to counter genetic tendencies towards obesity.


Centers for Disease Control and Prevention. (2010). Obesity and genetics. Retrieved April 12, 2010, from http://www.cdc.gov/Features/Obesity/.

Centers for Disease Control and Prevention. ( 2010). Obesity and genetics: What we know, what we don’t know and what it means. Retrieved April 12, 2010, from http://www.cdc.gov/genomics/resources/diseases/obesity/obesknow.htm.

Obesity 101. (n.d.). What is obesity? Retrieved April 12, 2010, from http://www.obesity101.com/101-1.htm.

Office of the Surgeon General. (n.d.). Surgeon General’s healthy weight advice for consumers. Retrieved April 12, 2010, from http://www.surgeongeneral.gov/topics/obesity/calltoaction/fact_advice.html.

West Virginia Department of Health and Human Resources. (n.d.). The burden of obesity. Retrieved April 12, 2010, from http://www.wvdhhr.org/bph/oehp/obesity/section1.htm.

World Health Organization. (2006). Obesity and overweight. Retrieved April 13, 2010, from http://www.who.int/mediacentre/factsheets/fs311/en/index.html.