SLBMI Nutrition and Weight Management Division>>Obesity

Obesity

In the last 20 years in the United States there has been a dramatic increase in rates of obesity.  According to results from a national study more than 64% of US adults are either overweight or obese (1999-2000 National Health and Nutrition Examination Survey).  This represents a two-fold increase since 1976-80.  As such, about 59 million American adults are obese and are at risk for a number of severe physical health problems.  And, the numbers continue to increase.

Definition
The Centers for Disease Control defines obesity as a range of weight that is greater than what is considered healthy for a given height.  Obesity ranges are generally determined using weight and height to calculate a number called the “body mass index” (BMI).  For most people BMI correlates highly with body fat percent, and is a quick and easy method to assess potential weight problems.

It should be noted that BMI is not an exact measure of body fat percent.  BMI may overestimate body fat percent in highly athletic and muscular individuals, and it may underestimate body fat percent in elderly and sedentary individuals who have lost a great deal of muscle.  But, for the average person over the age of 18 it is a reliable and widely used method.

For more information about the Body Mass Index (BMI), and to calculate your BMI go to http://www.cdc.gov/nccdphp/dnpa/bmi/index.htm

If you are interested in more sophisticated methods for measuring body fat content go to
http://www.simplefit.net/?page=measure-body-fat-percentage

Health Risks
The Centers for Disease Control and the American Medical Association both list obesity as a risk factor for several life-threatening illnesses including coronary heart disease, type 2 diabetes, stroke, gallbladder disease, sleep apnea and respiratory problems, osteoarthritis and some cancers (endometrial, breast, and colon).

Causes
The basic equation of weight gain is clear and consistent.  Consuming more calories than you use on a daily basis will result in weight gain, because your body will store excess calories as fat.

Increased calorie consumption + limited calorie use = weight gain

While the idea is fairly simple, current research has uncovered a number of factors that influence the equation.

Factors that can influence increased consumption of calories:

• Eating Habits and Diet: Eating high-calorie foods (such as high sugar and high fat content foods) and beverages (such as sugary sodas, beer, wine and spirits) increases the likelihood that you are consuming more calories than you can burn in a day.

• Binge Eating: A binge is defined as eating an excessive amount of food in a relatively brief period of time and experience a feeling of loss of control about the behavior.

• Pregnancy: Quite naturally women must eat more when they are pregnant to sustain the health of the fetus.  Of course, with the greater intake of calories, women gain weight, which is healthy and expected.  However, many women find it difficult to change eating habits and lose pregnancy weight after the baby is born.

• Quitting Smoking: Some people report that after they quit smoking they experience an increase in appetite and a renewed sense of taste and enjoyment in food, which can lead to increased calorie consumption and weight gain.

• Medications: Some people report experiencing increased feelings of hunger when taking some medications, which can lead to increased calorie consumption and weight gain.

Factors that can influence diminished use of calories:

• Inactive Lifestyle: Many people have sedentary jobs and do not engage in regular physical activity and exercise.  As such, they don’t burn as many calories as they consume.

• Quitting Smoking: Research suggests that the nicotine in cigarettes increases metabolism.  Therefore, when a person stops smoking and is no longer ingesting nicotine, they will burn fewer calories, with is a risk factor for weight gain.

• Medications: Some medications slow metabolic rates, thereby decreasing the number of calories a person burns.

• Physical Injury or Illness: Following an accident, surgery or injury some individuals experience a loss of mobility and are unable to continue with activities or exercise they had been doing regularly.  Other individuals who suffer with chronic conditions, such as arthritis or other forms of chronic pain, may also become increasingly inactive.  This inactivity is a risk factor for weight gain.

• Medical Problems: In rare cases obesity appears to be linked to medical causes, such as low thyroid functioning or Cushing’s syndrome (when the adrenal glands produce excess hormones).

Learn More About Obesity

The Centers for Disease Control: http://www.cdc.gov/nccdphp/dnpa/obesity/index.htm
The North American Association for the Study of Obesity: http://www.naaso.org/
The American Dietetic Association: http://www.eatright.org/cps/rde/xchg/ada/hs.xsl/index.html

Learn About How We Treat Obesity at St. Louis Behavioral Medicine Institute

For individuals (adults and adolescents) who want professional assistance with weight loss on an outpatient basis go to The Nutrition and Weight Management Service.

For individuals with binge eating problems, go to The Eating Disorders Program.

For those in ministry, clergy, men and women religious, who want a weight loss program that understands the unique stressors and challenges of ministry and religious life go to The Program for Psychology and Religion.

For individuals considering surgical treatment for obesity (bariatric surgery), it is recommended that the person obtain a pre-surgery psychological assessment: Bariatric Evaluation.