Obesity/Weight Loss Diagnosis

  • Diagnosis

    Obesity is a chronic disease. Being overweight is defined as having a body mass index (BMI) of 25.0 to 29.9, while obesity is defined as having a BMI of 30.0 or above. For Asian Americans, overweight is defined as having a BMI between 23 and 29.9, and obesity is defined by a BMI of 30.0 or greater. Figure 01. Your body mass index (BMI) is a measurement that is derived from a calculation of your weight relative to your height. Your BMI correlates fairly well with the amount of total body fat that you have.

    Being overweight or obese is hazardous to your health. In 1985, the US Surgeon General warned that as a result of being overweight or obese, 34 million Americans were at risk for developing heart disease, stroke, diabetes, and cancer. Since then, the numbers of Americans at risk has almost tripled. According to the 1998 National Heart, Lung, and Blood Institute report, over one-half of all Americans are now overweight or obese. Recent estimates attribute about 112, 000 deaths each year in the US to obesity, making it second only to cigarette smoking as a cause of death.

    Medical disorders such as high blood pressure, high cholesterol levels, and gallbladder disease are associated with obesity. Obesity has been shown to increase the risk of developing high blood pressure, adult-onset diabetes, heart attack, stroke, degenerative joint disease of the back and knees, gallstones, and certain forms of cancer such as that of the breast, prostate, and colon. Obese women commonly can have infertility problems, irregular menstrual flow, and urinary incontinence.

    The good news is that losing as little as 10% of your current weight will help to lower your risk of developing certain obesity-related diseases. One recent study, for instance, indicates that a modest loss of 5% to 10% of body weight can lower blood pressure and reduce your risk of developing diabetes.

    Affected individuals should seek treatment through clinical programs provided by licensed health care professionals. Bariatric physicians are specialized in treating obesity and its related diseases. Treatment is also offered through nonclinical commercial enterprises such as Weight Watchers.

    Click to enlarge: BMI calculator

    Figure 01. BMI calculator

    Obesity is a chronic disease caused by an interaction between genes and the environment.

    Obesity is caused by an energy imbalance that occurs when a person consumes more calories than he or she burns through physical activity. If you consume more calories than you burn, you will gain weight. Conversely, if you burn more calories than you consume, you will lose weight. Knowing that, why so many people consume more calories than they can burn is unknown. For most people, it isn't because of gluttony, lack of willpower, or laziness. Almost everyone who is overweight or obese has tried to lose weight, been temporarily successful, but failed to keep the lost weight and more from returning. Why is it so difficult to lose weight and keep it off? Scientists have only partial answers. They are still trying to sort out the complex interactions between genetic makeup and the environmental causes of obesity.

    Obesity has a strong genetic component, and tends to run in families. Family members share not only genes, but also diet and lifestyle habits that can contribute to obesity. In one study of adults who were adopted as children, researchers found that the subjects' adult weights were closer to their biological parents' weights than their adoptive parents. Apparently, in that study genetic makeup had more influence on those person's adult weights than did the environment provided by the adoptive family. Some experts estimated that 60% of our obesity is caused by genetic makeup, and 40% is caused by environmental factors.

    Environmental factors also play a significant role in causing obesity. The availability or lack of food, as well as economic status, are environmental factors that contribute to obesity. Environmental factors also include lifestyle behaviors such as what and how often you eat, and how active you are. Americans tend to like to eat a high-fat diet for reasons of taste and convenience. Also, many people, at least those in affluent industrialized countries, aren't physically active enough. Chronic sleep deprivation can also increase the risk of developing obesity.

    Many people eat in response to negative emotions such as anger, boredom, or sadness. However, most overweight people have no higher rates of diagnosed psychological disorders than people of normal weight. Binge-eating disorder, and an eating disorder in which people overeat for psychological reasons, can lead to obesity.

    Some prescription drugs and certain illnesses can cause or contribute to obesity. Hypothyroidism, Cushing's syndrome, and certain psychiatric and neurological problems can lead to weight gain. Certain drugs, including steroids and many medications used to treat psychiatric diseases such as depression, bipolar disorder, and schizophrenia, can cause excessive weight gain.

    For most people, weight gain leading to obesity occurs gradually, over a period of years. As you gain weight, you will notice that your clothes feel tight, and no longer fit. However, symptoms of being overweight and obese can be more serious than just noticing that your clothes are tight.

    Being overweight or obese can lead to joint pains, primarily in the low back, hip, and knee joints. People who are overweight are also more prone to develop carpel tunnel syndrome, and to develop rashes and fungal and bacterial infections of the skin. Overweight women have a higher chance of developing urinary incontinence, irregular menstrual cycles, and infertility. People who are overweight also get short of breath during exertion.

    Many overweight and obese people suffer from sleep apnea, a condition characterized by moments during sleep when breathing ceases. This can occur as often as hundreds of times per night and, if untreated, can lead to cardiovascular problems and premature death. Individuals with sleep apnea often feel very tired, even during the day.

    A combination of genetic and environmental influences are considered to be risk factors for weight gain and obesity. People with a family history of certain diseases, including heart disease and diabetes, are more likely to become obese and develop those same problems once obese. High blood pressure, high cholesterol, or high blood sugar levels are all warning signs of obesity-related diseases.

    For some women, pregnancy is a major risk factor for obesity. Although most women weigh only a few pounds more after pregnancy, about 15% of women put on an additional 10 pounds with each pregnancy.

    Underactive hypothyroid glands (hypothyroidism) have traditionally been thought to be a common cause of obesity. Of late, however, scientists feel that hypothyroidism rarely causes obesity because most obese patients who are treated for hypothyroidism do not lose their excess body weight.

    Overfeeding during infancy and an increase in fat cells and connective tissue that stores fat (adipose tissue) during infancy and childhood has been shown to predispose children to obesity later in life.

    Growing up in a low-income household limits access to high-nutrient, non-fatty foods. Therefore, being socially disadvantaged is an important risk factor for obesity; particularly for women.

    Leading a sedentary lifestyle is a risk factor for obesity. Physical activity not only increases your energy, but also helps to control your appetite.

    Using prescription drugs on a long-term basis has recently been recognized as a risk factor for obesity. Steroids and psychoactive drugs including traditional antidepressants (tricyclics, tetracyclics, and monamine oxidase inhibitors) and benzodiazepines, lithium, and antipsychotic drugs can cause weight gain.

    You can determine whether or not you are overweight by measuring your waist circumference and calculating your BMI Figure 01Figure 02. Having a BMI of over 30 kg/m2 indicates that you are obese. A BMI in the range of 25 to 29.9 indicates that you are overweight, while a BMI in the range of 18.5 to 24.9 represents a normal, healthy weight. For Asian Americans, a BMI of 23 to 29.9 is considered overweight. Since muscle weighs more than fat, you could have a high BMI if you are very fit and muscular. However, examples like these are relatively rare except in bodybuilders and football players.

    If you have excess fat in your abdominal area rather than in your hips and thighs, you are also at a higher risk of developing diabetes, high blood pressure, heart disease, and other diseases. For women, risk increases when your waist is more than 35 inches around. For men, risk increases when your waist is more than 40 inches around.

    People who have BMIs of 25 or more or high waist measurements and who also have two or more of the listed risk factors are strongly encouraged to lose weight.

    Your waist-to-hip ratio helps to determine your risk of death from heart failure. Recent studies indicate that the disposition of fat around the trunk is associated with increased risk of dying from heart failure. The distribution of fat is assessed by calculating a waist/hip ratio. In other words, measure your waist circumference, and divide it by your hip circumference. Men who have a ratio greater than 1.0, and women with a ratio greater than 0.8 are at highest risk for heart failure.

    Click to enlarge: Waist Measurement

    Figure 02. Waist Measurement

    Children should be taught healthy and nutritious eating and physical activity habits at an early age. Children, teens, and young adults should be taught to identify and overcome barriers to healthy eating and exercise. Studies show a direct correlation between the amount of television children watch and their body weight. Thus, children should be encouraged to watch TV less and exercise more.

    Prevention efforts aimed at children, when supported by adults, can be successful. Although there is an epidemic of childhood obesity in the US, studies show that overweight children who lose excess weight are more likely to keep it off than are adults. In addition, studies show that it is easier to teach and motivate children to eat well and exercise than it is for adults to adopt similar behaviors later in life.

  • Prevention and Screening

    Children should be taught healthy and nutritious eating and physical activity habits at an early age. Children, teens, and young adults should be taught to identify and overcome barriers to healthy eating and exercise. Studies show a direct correlation between the amount of television children watch and their body weight. Thus, children should be encouraged to watch TV less and exercise more.

    Prevention efforts aimed at children, when supported by adults, can be successful. Although there is an epidemic of childhood obesity in the US, studies show that overweight children who lose excess weight are more likely to keep it off than are adults. In addition, studies show that it is easier to teach and motivate children to eat well and exercise than it is for adults to adopt similar behaviors later in life.

Recommended Reading

Meet the Pharmacists

I'm Kristen Dore, PharmD. Welcome to PDR Health!

Check out my latest blog post on heartburn medication

Obesity/Weight Loss Related Drugs

Obesity/Weight Loss Related Conditions