Is obesity hereditary?
Obesity results from the energy imbalance that occurs when a person consumes more calories than their body burns. Obesity is a serious public health problem because it is associated with some of the leading causes of death worldwide, including diabetes, heart disease, stroke, and some types of cancer.
However, recent studies suggest that genetics contribute to 40-70% of obesity with the discovery of more than 50 genes that are strongly associated with obesity. While changes in the environment have significantly increased obesity rates over the last 20 years, the presence or absence of genetic factors protect us from or predispose us to obesity.
The strong heritability of obesity has been demonstrated in several twin and adoptee studies, in which obese individuals who were reared separately followed the same weight pattern as that of their biological parents and their identical twin. Metabolic rate, spontaneous physical activity, and thermic response to food seem to be heritable to a variable extent.
A study found that having an overweight or obese father and healthy-weight mother significantly increased the odds of childhood obesity; however, having an obese mother and a healthy-weight father was not associated with an increased risk of obesity in childhood.
In most obese people, no single genetic cause can be identified. Since 2006, genome-wide association studies have found more than 50 genes associated with obesity, most with very small effects. Several of these genes also have variants that are associated with monogenic obesity, a phenomenon that has been observed in many other common conditions. Most obesity seems to be multifactorial, that is, the result of complex interactions among many genes and environmental factors.
Genetic causes of obesity can be broadly classified into:
- Monogenic causes: those caused by a single gene mutation, primarily located in the leptin- melanocortin pathway.
- Syndromic obesity: severe obesity associated with other phenotypes such as neurodevelopmental abnormalities, and other organ/system malformations.
- Polygenic obesity: caused by cumulative contribution of a large number of genes whose effect is amplified in a ‘weight gain promoting’ environment.
Obesity Genetics: A Predisposition
More commonly, people who have obesity have multiple genes that predispose them to gain excess weight. One such gene is the fat mass and obesity-associated gene (FTO), which is found in up to 43% of the population. In the presence of readily accessible food, those with the fat mass and obesity-associated gene may have challenges limiting their caloric intake. The presence of this gene and other genes can cause:
- Increased hunger levels
- Increased caloric intake
- Reduced satiety
- Reduced control overeating
- Increased tendency to be sedentary
- Increased tendency to store body fat
Rarely, a clear pattern of inherited obesity within a family is caused by a specific variant of a single gene (monogenic obesity). Most obesity, however, probably results from complex interactions among multiple genes and environmental factors that remain poorly understood (multifactorial obesity).
If you have genes that predispose you to obesity, are you predestined to develop obesity? No! While these genes can increase appetite and reduce metabolism, following a consistent treatment plan that incorporates effective nutritional, physical activity, and behavioral approaches can help prevent and treat obesity.
If weight continues to be a struggle, consider it’s time to act! How? Just have a look on this method (MSP), it guarantees you to put an end to your obesity if you follow it strictly.