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What Are the Common Causes of Obesity?

Obesity is commonplace. More than 42 percent of Americans are obese. The rate of obesity has gone up by 12 percentage points over the last 20 years.

One reason why is that there are many causes of obesity. Yet very few people understand what causes obesity and why.

What are genetic and biological reasons for obesity? What about the American lifestyle lends itself to weight gain? What ingredients and medications should you avoid?

Answer these questions, and you can become an expert on how to prevent weight gain. Here is your quick guide.


Obesity runs through families. The fat mass and obesity-associated gene (FTO) can affect the levels of ghrelin in a person’s body. Ghrelin is a hormone that stimulates appetite and changes how a person stores fat.

A 2017 study found that people with the FTO gene had higher rates of binge eating disorders. The gene may impact brain function, modulating the response of cells to food cues. This can cause a person to eat more.

Genetics may be only one reason why obesity runs from generation to generation. Some areas are food deserts where people have less access to healthy choices.

Food Addiction

Your brain contains centers that produce hormones for productive activities. When you eat a delicious meal or exercise, your brain produces dopamine, which makes you feel joyous. This encourages you to do the same thing over and over again.

Sugar, saturated fat, and salt stimulate dopamine production. This encourages a person to eat more of those substances.

Enough consumption of sugary foods can distort the brain itself. It stops producing hormones for healthy activities and only produces them for unhealthy foods.

Food addiction is independent of food cravings. Some people crave unhealthy foods, but they can resist their cravings.

Addiction impacts the brain and is very difficult to resist. It requires extensive psychiatric support in order to combat.

Sedentary Lifestyle

More and more people work in offices. They sit at desks all day, burning very few calories. When they go home, they sit in front of a screen.

Fewer people are exercising. Only 53 percent of adults meet the CDC’s guidelines for aerobic and cardiovascular exercise.

A sedentary lifestyle triggers obesity in several ways. The less exercise a person performs, the fewer calories they use up. When a person eats caloric food and does not exercise, they can become obese quickly.

But exercise also encourages hormone production. Working out can keep a person’s insulin levels stable, preventing weight gain. Even little things like climbing stairs can help.

Sleep Deprivation

People eat food so they can feel energized throughout the day. If they don’t get enough sleep, they may continue eating so they can stay awake.

Sleep deprivation can also impact levels of ghrelin. The brain triggers ghrelin production when it is deprived of sleep. Conversely, the brain produces less insulin when it is tired.

Sleep-deprived people may not feel the energy to go and exercise. They may eat more and they may burn less, triggering obesity.

Processed Ingredients

A person can become obese eating too much of any food. But processed ingredients trigger obesity far more than natural ones. They can also induce several medical problems related to obesity.

Processed sugar offers no substantial health benefits. Most forms of it are half glucose and half fructose. Fructose encourages blood cells to resist insulin, triggering obesity and diabetes.

Non-sugar additives may be even worse. As the name suggests, high fructose corn syrup contains extreme levels of fructose. It can trigger type 2 diabetes with enough consumption, yet it is present in a number of foods.

Trans fats are artificial fats that manufacturers put into processed meats and desserts. It can raise bad cholesterol while lowering good cholesterol. It can trigger cardiovascular problems, including heart disease.


Several medications lead people to gain weight. Antipsychotics, anticonvulsants, and antidepressants can induce weight gain over several months.

This may be because these medications induce drowsiness. If a person feels too tired to exercise, they may not work out. Keep in mind that side effects can vary, which makes it hard to understand why medications may cause obesity.


Scientists debate obesity causes. Some argue that saturated fats cause obesity, while others assert that carbohydrates are the cause. This results in many people overeating carbs or fats, which causes weight gain.

There is plenty of misinformation about how to start losing weight. Some authors say they have foolproof solutions for weight loss, but they just endorse unhealthy eating habits. They may not teach a person how to set health goals, making it hard to track progress.

Many people are not aware of the signs of obesity. They do not know when a person becomes overweight or obese.

Some of this misinformation comes from marketing. Fast and junk food manufacturers have substantial marketing budgets. They use terms like “all-natural” that conceal the caloric and fatty nature of their food.

Marketing is especially a concern for obesity in children. Fast food chains target children with mascots and product placement in movies.

The Major Causes of Obesity

Several causes of obesity can trigger problems. Genetics can affect how the body processes fats. The brain can become addicted to fatty and sugary foods.

People work in offices more, giving themselves fewer chances to exercise. They sleep less so they produce less ghrelin. When they eat, they eat processed foods that are high in calories.


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