Why Stress Causes Weight Gain

Weight gain is a problem that affects millions of Americans each year. Obesity affects over 93 million adults. Conditions related to obesity include heart disease, stroke, type 2 diabetes,  and certain types of cancer that are some of the leading causes of preventable, premature death. The estimated annual medical cost of obesity in the United States is over $147 billion. There appears to be a clear association with chronic stress and weight gain and obesity.

Stress causes the production of cortisol which disrupts the production and function of many hormones that help us to maintain a healthy weight.   Cortisol suppresses the activity of thyroid and growth hormone. It also disrupts the production of progesterone and testosterone which results in the storage of more fat. Cortisol makes the body less sensitive to insulin which leads to insulin resistance.

Key Points

• • • Stress decreases serotonin levels, which may affect appetite and cause food craving.
    • Cortisol makes most body cells resistant to glucose storage.
    • Stress can lead to diabetes and obesity.
    • Abdominal obesity is commonly associated with a prolonged stress response.

Appetite and Abdominal Fat

Chronic stress puts a tremendous strain on the body. The persistent release of cortisol can lead to continuous hunger because the body needs the energy to fight or flee from a threat. However, when glucose is not utilized to run or fight, the body stores glucose as fat in the abdomen. In addition, elevated cortisol levels decrease thyroid hormone functioning which leads to weight gain.  Chronic stress and elevated cortisol levels have been specifically linked to increased abdominal fat. Developing a beer belly may not seem to be any worse than thunder thighs.  However, in fact, the storage of fat around the abdomen is associated with a much higher risk of cardiovascular disease, stroke, and heart attacks. Each individual’s likelihood of developing abdominal fat varies according to genetics, diet, and lifestyle. These factors explain why some individuals tend to gain weight more easily around the midsection while others do not.

Emotional Eating

Very few of us are aware of the complex chemistry behind nervous eating. We just know that we tend to feel better after having a tasty slice of cake or a bag of chocolates. People under chronic stress tend to gravitate towards foods that are higher in salt, fat, and sugar. Studies show that foods high in fat, sugar, or salt are, in fact, addictive. These types of food release opioids in the brain, which act like morphine to relieve stress and pain. We literally become food addicts, eating large amounts of junk foods even when we are not hungry.

Food Cravings

The craving to eat food is a powerful survival mechanism that forces the body to eat what it desperately needs. Under prolonged stress, cortisol depletes the calming feel-good neurotransmitter serotonin, while increasing epinephrine levels. This combination of decreased serotonin and increased epinephrine causes depression and anxiety, respectively. Consuming carbohydrates increases serotonin.  When one eats comfort foods, glucose levels increase, which is followed by a rise in serotonin and temporarily elevation in mood.

Although it is not exactly known why some people react to stress by eating more and others react by losing their appetite, recent studies suggest that there is a complex interaction between stress, metabolism, and a change in eating behavior. Anxiety, depression, and altered brain metabolism have been linked to emotional overeating and under-eating. The chemical differences between individuals who stress eat and those who do not, appear to be higher levels of cortisol, glucose, and cholesterol in the bloodstream of stress eaters.

Stress, Appetite, and Exercise

Several large studies have shown that losing only 6% of an individual’s body weight can prevent 3 out of 5 cases of diabetes in younger individuals, and 70% of cases in older individuals. Lowering your sugar and carbohydrate intake, while at the same time burning your body’s glucose stores through exercise lowers your risk for diabetes.

Most of us know from experience that exercise reduces our stress levels and appetite. However, a new study suggests that not all exercise reduces appetite equally. University students who work out on a treadmill, a cardiovascular exercise, have much lower appetites than those who do other forms of exercise, such as weight lifting, a resistance exercise.

Several recent studies also show that even healthy individuals who are not at risk for metabolic syndrome, develop symptoms when exposed to chronic stress. In one study, 16 healthy male sailors in their 20’s and 30’s were followed over the course of the sailing competition. Initially, at the beginning of the race, the sailor’s overall weight dropped. However, as the competition progressed, they began to gain abdominal fat. They also were found to have high levels of triglycerides in their bloodstream. The researchers concluded that chronic stress over a period of three months led to measurable and significant biochemical changes in the metabolism of healthy individuals in spite of healthy diets and ample daily exercise. In conclusion, anyone with prolonged stress is at risk for developing excess abdominal fat, hypertension, diabetes, and vascular disease if undiagnosed and untreated.