Stress and related issues
Obesity experts now believe that a number of different aspects of American society may conspire to promote weight gain. Stress is a common thread intertwining these factors. For example, these days it’s commonplace to work long hours and take shorter or less frequent vacations. In many families, both parents work, which makes it harder to find time for families to shop, prepare, and eat healthy foods together. Round-the-clock TV news means we hear more frequent reports of child abductions and random violent acts. This does more than increase stress levels; it also makes parents more reluctant to allow children to ride their bikes to the park to play. Parents end up driving kids to play dates and structured activities, which means less activity for the kids and more stress for parents.Time pressures — whether for school, work, or family obligations — often lead people to eat on the run and to sacrifice sleep, both of which can contribute to weight gain.
Some researchers also think that the very act of eating irregularly and on the run may contribute to obesity. Neurological evidence indicates that the brain’s biological clock — the pacemaker that controls numerous other daily rhythms in our bodies — may also help to regulate hunger and satiety signals. Ideally, these signals should keep our weight steady. They should prompt us to eat when our body fat falls below a certain level or when we need more body fat (during pregnancy, for example), and they should tell us when we feel satiated and should stop eating. Close connections between the brain’s pacemaker and the appetite control center in the hypothalamus suggest that hunger and satiety are affected by temporal cues. Irregular eating patterns may disrupt the effectiveness of these cues in a way that promotes obesity.
Similarly, research shows that the less you sleep, the more likely you are to gain weight. Lack of sufficient sleep tends to disrupt hormones that control hunger and appetite. In a 2004 study of more than 1,000 volunteers, researchers found that people who slept less than eight hours a night had higher levels of body fat than those who slept more, and the people who slept the fewest hours weighed the most.
Stress and lack of sleep are closely connected to psychological well-being, which can also affect diet and appetite, as anyone who’s ever gorged on cookies or potato chips when feeling anxious or sad can attest. Studies have demonstrated that some people eat more when affected by depression, anxiety, or other emotional disorders. In turn, overweight and obesity themselves can promote emotional disorders: If you repeatedly try to lose weight and fail, or if you succeed in losing weight only to gain it all back, the struggle can cause tremendous frustration over time, which can cause or worsen anxiety and depression. A cycle develops that leads to greater and greater obesity, associated with increasingly severe emotional difficulties.
A widespread problem
Percent overweight
Sixty percent of adults in the U.S.
are overweight
Percent of obese adults
One-third of American adults have obesity
Other causes of obesity
Clearly, our responses to today’s obesity-promoting environment, in tandem with genetic influences, are the most significant causes of overweight and obesity. But in some people, drug side effects, illnesses, and genetic disorders can also play a role.
Drug side effects
Several prescription drugs can cause weight gain as a side effect by increasing appetite or slowing metabolism. These include corticosteroids such as hydrocortisone (used for a variety of conditions to reduce inflammation); estrogen and progesterone (used in oral contraceptives); anticonvulsants such as valproic acid (Depakote, others); certain anticancer medications; and drugs such as olanzapine (Zyprexa), haloperidol (Haldol), lithium (Eskalith, Lithobid), and clozapine (Clozaril), which are used to treat psychiatric conditions.
Paradoxically, weight gain can also be a side effect of some drugs used to treat conditions that result from obesity itself. Among these drugs are insulin and glyburide (DiaBeta and others); these are treatments for diabetes, which is common among people with weight disorders. Several antidepressants may cause patients to put on weight, including tricyclic antidepressants such as imipramine (Tofranil) or desipramine (Norpramin, Pertofrane), monoamine oxidase inhibitors (MAOIs), and selective serotonin reuptake inhibitors (SSRIs) such as paroxetine (Paxil), citalopram (Celexa), escitalopram (Lexapro), sertraline (Zoloft), fluvoxamine (Luvox), and fluoxetine (Prozac).
When used to treat depression, SSRIs may cause weight loss initially, but within six months of treatment they can induce weight gain in a significant number of patients. On the other hand, sibutramine (Meridia), another drug that stimulates serotonin (like the SSRIs), is an appetite suppressant that’s used to promote weight loss. And in a small number of patients, SSRIs such as Prozac actually cause weight loss, making them useful as a therapy for weight disorders. Much more needs to be learned in this area; the relationship between weight regulation and serotonin (a key chemical communicator in the brain and elsewhere in the body) is obviously complex.
Illnesses that affect weight
A few illnesses that are characterized by an imbalance or an abnormality in your endocrine glands can also affect your weight. These include hypothyroidism (an underactive thyroid), polycystic ovarian syndrome, and certain unusual tumors of the pituitary gland, adrenal glands, or the pancreas. However, in the vast majority of people, these illnesses are not responsible for weight gain. Most are extremely rare. Hypothyroidism, which is the most common, is seldom the main reason for overweight or obesity. Treatment with thyroid hormone, while medically necessary, does not usually cause a significant weight reduction.
Genetic disorders
Obesity is also a symptom of some rare and complex disorders caused by genetic defects. These obesity syndromes usually appear in early childhood and are tied to several additional medical problems. One such disorder is Prader-Willi syndrome, a form of obesity associated with mild mental retardation that occurs in about 1 in 25,000 people and has been traced to abnormalities in a group of genes on chromosome 15. People with this disorder are unusually short and have primarily upper-body obesity. A less common disorder, Bardet-Biedl syndrome, is similar to Prader-Willi syndrome, but is caused by abnormalities in different genes. Several other rare genetic syndromes cause obesity, but account for only a tiny fraction of all weight disorders.
Learn weight control strategies in our special report: Weigh Less, Live Longer
Weigh Less, Live Longer: Strategies for Successful Weight Loss
More than half of all adults in the United States are overweight! That’s a staggering statistic with tremendous health implications. The good news is that you can lose weight and keep it off. The Weigh Less, Live Longer Report can help you tailor a successful weight control plan that fits your particular needs. Read more »