Obesity, a condition where a person is significantly or extremely overweight, can raise risk for several serious medical conditions, which are listed below. Though this is a frightening list, remember that, by losing weight, maintaining a healthy diet, and staying active, you may be able to reduce your risk of these conditions and enjoy improved overall health.
Factors that contribute to excess weight may be related to genes, metabolism, environment, culture, and socioeconomic status. As well, certain diseases and medications may cause weight gain. Examples of these diseases include polycystic ovarian syndrome and Cushing’s disease; drugs that may contribute to weight gain include steroids and some antidepressants.
Overweight and obesity refer to ranges of weight that exceed what’s generally considered healthy in relation to a person’s height. There are several ways to define obesity or to determine whether an individual is obese. One tool that’s often used is the body mass index (BMI). BMI is a ratio of weight to height. It’s not a completely reliable measurement because it correlates rather than directly measures body fat; this means that muscular, lean athletes may actually have a BMI that inaccurately indicates that they are overweight. BMI is categorized as follows:
Some additional ways to estimate body fat include skin fold thickness and waist-to-hip circumference ratios and techniques such as ultrasound, computed tomography, and magnetic resonance imaging (MRI).
Another important consideration in body weight is waist measurement. Though waist size may not be used to determine obesity and other weight categories, it is a significant indicator of risk for medical conditions. Excess fat in the abdomen (or around the waist) may increase obesity-related health risks more than fat carried anywhere else on the body. For women, a waist measurement of more than 35 inches may indicate increased risk; for men, the measurement for higher risk is more than 40 inches.
According to the Centers for Disease Control and Prevention (CDC), in 2007-2008 one-third of U.S. adults were obese. Parts of the Southeast, Appalachia, and some tribal lands in the West and Northern Plains have the nation’s highest rates of obesity. The CDC also reports that, by racial and ethnic groups, African Americans have the highest rates of obesity, and Hispanics also have high prevalence (51 percent and 21 percent higher compared with Whites, respectively).
The latest global obesity projections from the World Health Organization (WHO) state that in 2005 1.6 billion adults were overweight and at least 400 million adults were obese. The WHO also explains that although overweight and obesity were once considered problems only in high-income countries, rates in low- and middle-income countries are rising dramatically. The cause? The WHO points to a global shift towards higher consumption of foods that are high in calories, fat, and sugars but low in vitamins, minerals, and other micronutrients. As well, levels of physical activity are decreasing around the world with the growth of sedentary forms of work, changing modes of transportation, and an increasing number of people living in urban settings.
There are prescription medications for weight-loss, but it’s important to note that these should be used only by people who are at increased medical risk because of their weight. These medications are only approved for individuals with a BMI of 30 and above and those with a BMI of 27 and above with an obesity-related condition like high blood pressure, type 2 diabetes, or dyslipidemia (abnormal amounts of fat in the blood). Side effects of these drugs tend to be mild, but serious complications have also been reported. People taking weight-loss medications should also follow a healthy-eating plan and maintain regular physical activity.
Types of weight-loss medications include appetite suppressants and lipase inhibitors. Appetite suppressants affect brain chemicals to decrease appetite and increase the feeling of being full; examples include sibutramine and phentermine. Lipase inhibitors reduce the body’s ability to absorb dietary fat by blocking the enzyme lipase, which breaks down dietary fat. Orlistat is a lipase inhibitor.
There are several risks associated with weight-loss medications. Side effects vary by type of drug. They may include intestinal issues like cramping, gas, diarrhea, and leakage of oily stool; increased blood pressure and heart rate; headache, dry mouth, constipation, and insomnia. Talk with your doctor about the risks and benefits of the particular weight-loss medication(s) you are considering taking. Tell your doctor about other health conditions—like high blood pressure, heart disease, irregular heartbeat, or history of stroke—as these may affect which medications you can safely take.
For people who are severely obese and haven’t been able to lose weight through diet and lifestyle changes, bariatric surgery is an option. Individuals who suffer from serious obesity-related health problems may also consider surgery. There are several different approaches to bariatric surgery, all of which promote weight loss through procedures to limit food intake and/or limit absorption of food. Food intake is limited by surgically reducing the size of the stomach and thus the amount of food it can hold; absorption is limited by rerouting food away from a portion of the digestive tract and directly to the small intestine.
In order for bariatric surgery to be successful, patients must maintain healthy eating habits and be physically active.
Potential early complications of bariatric surgery include bleeding, infection, leaks from sites where intestines are sown together to reroute food, and blood clots in the legs (which can progress to the lungs and heart). Additional complications like malnutrition and strictures (narrowing of the sites where the intestine is joined) can occur later.