Is Obesity Genetic? Here's What Science Has to Say

Who hasn’t shied away from the weighing scale at some point in their life? For the most part, we see weight gain as the product of excessive food consumption, making it a sensitive topic of discussion. However, could there be more to obesity than eating too much? Is obesity genetic? This article digs deeper into this question to provide a better understanding of how obesity happens. 

Is Obesity Genetic? 

Obesity refers to abnormal or excessive fat buildup which poses a health concern. A person is said to be overweight when their body mass index (BMI) — a number which describes their weight in relation to their height — reaches 25 or higher. Meanwhile, an obese person has a BMI of 30 or higher. (Though BMI is a useful tool for doctors, it is important to note that it doesn’t measure actual fat or the health of an individual; it is only part of the picture.)

In recent years, the number of obesity cases continues to rise as increased calorie consumption and decreased physical exercise becomes more prevalent in modern society. While many say that these changes play a big role in the rise of obesity rates, it is undeniable that genetic factors also take part in the equation.

Doctors and healthcare providers alike often look into familial background and health history in regular health check-ups. The impact of shared genetics among close relatives is shown in this family health history. Thus, regular check-ups help doctors identify those who are at high risk of obesity-related disorders such as:

Is Obesity Genetic? What Science Has To Say 

Science has so much to say when it comes to the question “Is obesity genetic?”

For starters, genes do play a significant role in human physiology, adaptation, development, and even other aspects of life. To control food intake, the brain receives signals from fat tissue, the pancreas, and the digestive tract. Hormones like leptin, insulin, and ghrelin transmit these messages. The brain then coordinates these impulses with other inputs to be able to send instructions to the body. The result is either of two outcomes: consume more and spend less energy, or the opposite. Even the smallest alterations in these genes can influence their activity levels.

How Genes Predispose You to Obesity

Obese people are more likely to have multiple genes that predispose them to gain excess weight. The fat mass and obesity-associated gene (FTO) — present in about 43% of the population — is a considerable factor. Those with this gene may have difficulty limiting their caloric intake in the presence of readily available food.

The presence of this gene, as well as other genes, can result in:

• Increased hunger levels
• Increased caloric intake
• Reduced satiety
• Reduced control in overeating
• Increased tendency to be sedentary
• Increased tendency to store body fat

In addition to that, genes can also directly contribute to obesity in such disorders as Bardet-Biedl syndrome and Prader-Willi syndrome.

Moreover, recent research revealed that genetics play a role in 40-70% of obesity cases. Researchers also found out that there are more than 50 genes closely linked to obesity. 

Below are some gene variants that may be associated with obesity:

• ADIPOQ (Adipocyte-, C1q-, and collagen domain-containing)
• FTO (Fat mass- and obesity-associated gene)
• LEP (Leptin)
• LEPR (Leptin receptor)
• INSIG2 (Insulin-induced gene 2)
• MC4R (Melanocortin 4 receptor)
• PCSK1 (Proprotein convertase subtilisin/kexin type 1)
• PPARG (Peroxisome proliferator-activated receptor gamma)

Several of these genes link to a phenomenon seen in a variety of other common conditions (monogenetic obesity). However, a significant proportion of obesity appears to depend on many factors. Gene expression is brought about by the result of complex interactions between genes and the environment.

Simply put, just because you have genes that are associated with obesity doesn’t automatically mean you will be obese.

Key Takeaways

Is obesity genetic? Yes, it can be genetic, but there are also a large number of factors that contribute to its overall prevalence. Behavior, lifestyle, and environmental setting may also contribute to being overweight or obese. 

Understanding how genes come into play and how they lead to obesity can be helpful in finding better strategies for obesity prevention and treatment. Ultimately, it is important to keep in mind that genetic risk is just a small part of the equation. You can still take charge of other factors that lead to obesity by leading a healthy lifestyle.

Learn more about Obesity here.