In this part of our continuing series on obesity, we are going to look at a very common and over-simplified contributor to obesity: stress. For years, many people have suspected that stress and obesity are linked, and now, scientific research has found evidence to support this connection. Specific biochemical reactions appear to help explain this link and, as doctors better understand these reasons, they may be better able to address the obesity epidemic facing the United States.
There is much truth behind the phrase “stress-eating.” Stress, the hormones it unleashes, and the effects of high-fat, sugary “comfort foods” push people toward overeating. Researchers have linked weight gain to stress and according to an American Psychological Association survey, about one-fourth of Americans rate their stress level as 8 or more on a 10-point scale.
In the short term, stress can shut down appetite. The nervous system sends messages to the adrenal glands (located atop the kidneys) to pump out the hormone epinephrine, also known as adrenaline. Epinephrine helps trigger the body’s fight-or-flight response, a revved-up physiological state that temporarily puts hunger on hold.
But if stress persists, it’s a different story. The adrenal glands release another hormone called cortisol, which increases appetite and may also ramp up motivation in general, including the motivation to eat. Once a stressful episode is over, cortisol levels should fall, but if the stress doesn’t go away – or if a person’s stress response gets stuck in the “on” position – the cortisol level may stay elevated.
The most insidious aspect of the link between stress and obesity is that it tends to be self-reinforcing. Very often, when people are stressed, they may eat inappropriately. This behavior can result in weight gain which can cause more stress – thus, a vicious cycle develops.
So, why do people stress eat? Some research suggests a gender difference in stress-coping behavior. A Finnish study that included over 5,000 men and women showed that obesity was associated with stress-related eating in women, but not in men.
The most insidious aspect of the link between stress
and obesity is that it tends to be self-reinforcing.
Harvard researchers have reported that stress from work and other sorts of problems correlates with weight gain, but only in those who were overweight at the beginning of the study period. One theory is that overweight people have elevated insulin levels, and stress-related weight gain is more likely to occur in the presence of high insulin.
The results of a recent British study do link obesity with long-term stress. The researchers came to their conclusion after measuring the amount of cortisol in the hair of study participants. The study showed that the individuals with higher levels of cortisol in their hair had larger waist circumference and were more persistently overweight. Those classified as obese based on their BMI or waist circumference (more than 40 inches in men or 34.5 inches in women) had particularly high cortisol levels.
Stress also seems to affect food preferences. Numerous studies have shown that physical or emotional distress increases the intake of food high in fat, sugar, or both. High cortisol levels, in combination with high insulin levels, may be responsible for this. Other research suggests that ghrelin, a “hunger hormone,” may have a role.
Once ingested, high-fat and sugary foods seem to have a feedback effect that dampens stress related responses and emotions. They really are “comfort” foods in that they seem to counteract stress – and this may contribute to people’s stress-induced craving for those foods.
Of course, overeating isn’t the only stress-related behavior that can add pounds. Stressed people also lose sleep, exercise less and drink more alcohol, all of which can contribute to excess weight.
With all of the science explaining the different pathways stress uses to cause obesity, how can an individual manage and avoid this terrible process? When stress affects our appetite and waistline, we can forestall further weight gain by ridding the refrigerator and cupboards of high-fat, sugary foods. Keeping those “comfort foods” handy is just inviting trouble.
Here are some other suggestions for countering stress-eating:
- Don’t allow yourself to become too hungry. When you go too long without eating, you get a drop in your blood sugar. It’s very hard to think rationally when your blood sugar levels are that low. Eat smaller, more frequent meals.
- Keep portion size in mind. Smaller portions can help keep your total calorie intake under control.
- Eat healthy snacks that combine protein and carbohydrates. The body digests them more slowly, allowing you to feel fuller longer.
- Think about what you’re eating. When people are really stressed, they think that paying attention to their diet will cause more stress. However, the opposite is frequently true and eating properly gives your body the fuel to fight stress.
Beyond managing your food choices, some of the best measures for preventing weight gain in times of stress is to address the underlying cause, first. There are many methods of managing stress, but some of the simplest can be the most effective. For instance, countless studies have shown that meditation reduces stress and may also help people become more mindful of food choices.
Likewise, a key aspect of stress relief can be exercise. While cortisol levels vary depending on the intensity and duration of exercise, overall exercise can blunt some of the negative effects of stress. Some activities, such as yoga and tai chi, have elements of both exercise and meditation.
Finally, maintaining a strong social support system is integral. Friends, family, and other sources of social support seem to have a buffering effect on the stress that people experience. For example, research suggests that people working in stressful situations, like hospital emergency departments, have better mental health if they have adequate social support. But even people who live and work in situations where the stakes aren’t as high occasionally need help from friends and family.
Ultimately, the best long-term solution is to deal with stress in a manner not associated with eating. That may be easier said than done; however, finding ways to manage your stress is essential to your overall health. If you find yourself reaching for high-fat, sugary snacks when you’re feeling stressed, know that you’re not alone. Fortunately, though, you can break this cycle. Find ways to minimize stress in your life and focus on making better food choices. Stress may be a part of life, but it doesn’t have to lead to weight gain.