Obesity and Genetics

Do genes determine one’s risk of becoming obese? According to the Centers for Disease Control and Prevention (CDC), they may play a role. Although the CDC is quick to point out that genes are not responsible for the current obesity epidemic occurring in the United States, where over one-third of the population is classified as clinically obese, the fact that some people in an environment become obese while others do not, suggests they do play a role.

Genes can influence behavior–such as activity level and amount of food consumed–and how bodies react to the food that’s consumed. While some people can eat what seems like large amounts of food without gaining weight, others can eat the same amount and experience different results. A body’s metabolism and the degree to which they store and utilize fat can vary due to their genetic make up.

Is There an Obesity Gene?

It is rare for obesity to be caused by a single gene (monogenic obesity). Most cases of obesity today are caused by changes or variants in multiple genes (polygenic obesity). This condition does not discriminate based on age, wealth, or intelligence. While it may seem that obesity “runs in the family,” it’s important to note that often those family members have spent long periods of time living in the same, perhaps unhealthy, environment.

Researchers discovered the first obesity-related gene in 2007. This common gene variant increases one’s risk of developing obesity by 20 to 30 percent. While many more genes have been identified as related to body mass index (BMI), genes are still believed to play a minor role in the development of obesity.

Those who have the obesity gene can easily offset its consequences with proper diet and exercise. According to a 2017 article, for those that carry the gene, “regular exercise seemed to reduce the effects of their DNA by about one-third.”

What You Eat Counts

Although how much one eats affects the risk of developing obesity, quantity of food is not the only factor that determines whether someone genetically prone to obesity will develop the disease.  What you eat is also important. A 2014 study found that fried foods could interact with obesity-related genes. Researchers are currently conducting more studies to explore the relationship between diet, obesity, and genetics.

In addition, consuming overly processed foods or those high in fat–even in moderate quantities–can lead to excessive weight gain over time. This is due to more than how the body processes these types of foods. Research suggests that certain foods may actually increase the likelihood of overeating.  

Low fat diets, often touted as the key to weight loss, can actually do the opposite. These diets are often higher in unhealthy carbohydrates, which can increase the chance of weight gain and disease development. Diets that are higher in good fats (unsaturated) and proteins coupled with low carbohydrates have been shown to decrease overeating and subsequent weight gain.

Environment’s Role in Obesity

As genes take many generations to undergo major changes, most researchers agree that environment is a major contributor to the significant increase in obesity over the last four decades. Environmental factors thought to play a role include:

• Easy access to fast and unhealthy foods at all hours
• More processed foods and sugar-filled drinks
• Advances in technology that contribute to a more sedentary lifestyle such as a wider variety of television choices and time on computers and smart devices
• Less manual labor

Working longer hours and experiencing more stress on the job can also lead to weight gain. Extra hours at work can limit time available for physical activity and lead to consumption of quick and unhealthy foods. Limited time for meals and access to unhealthy food choices, such as those from vending machines, serve as a toxic environment not conducive to weight maintenance and good health.

You Are the Master of Your Fate

Research has thus far shown that genes play only a small part in the risk of becoming obese and do not alone determine one’s fate. Studies have also revealed that those who have obesity genes can counteract their effects by developing more healthy habits.

Although researchers currently do not fully understand what specific roles genetics and environment play in becoming obese, being active, eating the right foods, and limiting the amount of food eaten can go a long way in preventing obesity and helping those who are overweight drop the pounds and improve their health.

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