Obesity In The United States
Dr. Tania M. Bandak, MD, MPH
Hampden County Physician Associates, LLC
Springfield, MA (USA)
Malnutrition is arguably one of the most pervasive, destructive diseases facing humankind. Between under-nutrition and over-nutrition, people from every continent, race, religion, class, gender and age group face the challenge of not having adequate nutritional intake to maximize their physical health. In the developed world, and increasingly in parts of the developing world, the form malnutrition has taken is obesity. Obesity has in fact become so prevalent that the World Health Organization has classified it as a global epidemic (1). The past two decades in particular have seen an explosion of the rates of obesity, especially in the United States.
II. Definition of Obesity:
The Body Mass Index, a ratio between weight and height (kg/m2), has become the standard used to refer to an individual's relative weight. BMIs between 25 and 29.9 are classified as "overweight" while BMI's greater than 30 are classified as obese.
Obesity is further broken down into 3 classes: Class I (BMI 30-34.9), Class II (BMI 35-39.9) and Class III (BMI>40). The rationale for categorizing BMIs in such a manner is that the risk factors for various diseases, as well as the treatment options vary somewhat according to which category a patient's BMI falls in.
Recently, large waist circumference (>40 inches in men and >35 inches in women) has been receiving increasing attention as perhaps being more closely correlated with cardiovascular risk than BMI, giving support to the theory an individual who is "apple-shaped" is more at risk than one who is "pear-shaped".
III. Prevalence and Demographics of Obesity in the US:
According to the National Task Force on the Prevention and Treatment of Obesity, more than 60% of U.S. adults are above their ideal weight, and the rate of obesity (BMI>30) has increased from 15% to 27% in the past twenty years (2). Various factors, including increasingly sedentary lifestyles, childhood use of TV, chaotic schedules and quick, easy access to high-fat fast foods have been stipulated as possible contributors to this trend. If such socio-cultural practices continue, as the population continues to age and as childhood obesity rates increase, it would not be surprising to see the prevalence of obesity increase further in the next couple of decades.
Though the rates of overweight and obesity appear to be slightly lower in women than in men in general, (51% as opposed to 60%), African-American women, Mexican-American women and women of low socioeconomic status have even higher rates than the general public (3).
IV. Health Consequences of Obesity:
A. Health Consequences of Obesity in the General Population
Obesity increases mortality, especially cardiovascular mortality. Obese adults have a 50-100% increased risk of premature death compared to non-obese adults (4). This risk increases as BMI increases. Therefore, while overweight individuals have only a mild increase risk of adverse health outcomes, as one progresses into the higher classes of obesity, this risk increases substantially.
The adverse health outcomes associated with obesity are numerous. Cardiovascular risk is clearly the most significant, with rates of hypertension, dyslipidemia, coronary artery disease, stroke being up to two times greater in obese individuals (5). There is some evidence cardiovascular risk is greater for obese African-American and Hispanic women than for obese individuals in general (6). This is particularly disturbing since it is in these groups that the diagnosis and treatment of heart disease lags behind that of men.
Endocrinological abnormalities such as type 2 diabetes mellitus and the metabolic syndrome are also more prevalent in the obese, as are gallbladder disease, sleep apnea, deep vein thrombosis, osteoarthritis and cancer.
B. Health Consequences of Obesity in Women
In addition to the above-mentioned risks of obesity, obesity incurs additional risks for women. Obese women have higher rates of endometrial, breast and colon cancer, as well as decreased fertility and increased rates of emotional distress (3). One study suggested that obese women have an increased risk of OCP (Oral Contraceptive Pills) failure, particularly if using low dose OCPs (7). Cesarean section rates also increase with increasing BMI, with a rate of 20.2% in women with BMI <29 to 45.9% in women with a BMI>39.9 (8). Women with BMIs >35 also have increased risk of pregnancy complications including an increased incidence of LGA (Large for Gestational Age) infants (if their pregnancy weight gain >25lbs), gestational diabetes, preeclampsia and arrest of labor (9). Obese women may also receive inadequate gynecological care. They are less likely to receive pelvic exams, PAP smears and breast exams, and are more likely to be treated with disrespect (2). Being that obese women are also less likely to seek medical care, it becomes apparent that the sociocultural stigma of obesity may have serious physical consequences.
V. Management of Obesity:
A. Does weight loss help?
Weight loss, even modest amounts has numerous beneficial cardiovascular effects. Blood pressure, LDL, triglycerides and blood glucose are all lowered, and HDL is increased, thereby improving one's overall cardiovascular profile (10).
B. Who should be counseled to lose weight?
Even though a lifestyle which includes regular exercise and a healthful diet is recommended for everyone, it is important to identify who would most benefit from a more aggressive approach to weight management. Most importantly, the patient has to be willing to address the problem and the necessary often challenging behavioral changes. Those whom the health care provider should encourage to lose weight are those who are overweight and/or have a large waist circumference (WC) and have 2 or more cardiovascular (CVD) risk factors and those who are obese. Patients who are overweight and/or have a large WC and have less than 2 CVD risk factors should be counseled to avoid further weight gain (11).
C. How much do you need to lose?
Small amounts of weight loss over long periods of time go a long away. Losing small amounts of weight (5-10% of initial body weight) through plans which include exercise, decrease an individual's cardiovascular risk by decreasing blood pressure, improving lipid profiles and glycemic control and decreasing mortality (6,1).
Contrary to popular belief, reducing weight to the normal BMI range is not an adequate short-term goal, as it sets many up for failure and may encourage unhealthy weight loss regimens. Current recommendations suggest a 10% weight reduction over six months, at a rate of 1-2 lbs/wk. After the six month period is over, weight goals may be reevaluated.
D. What are the different strategies for weight loss and are they effective?
The media offers an overwhelming abundance of weight loss options, some of which may be helpful for some and others which may be harmful. Most, however, simply do not work in the long term. Losing weight is an incredibly challenging, often life-altering process. "Quick fixes", however appealing they may sound, do not incorporate all the changes needed not only to get the number on the scale down, but to have that number reflect a healthier individual.
It is probably for the above stated reason that structured weight loss programs which incorporate well organized, multidisciplinary strategies tend to have better results than individual attempts (12). The preferences of the individual need to be considered when recommending a strategy, as most people know in what sort of environment they perform best. Some may prefer to structure their own individual or small group "programs". For these individuals, close, routine follow-up with an interested health care provider is beneficial.
Weight loss techniques may include the following. Each will be discussed in the following sections:
1) Behavioral Strategies: Weight loss requires behavioral change. Some may accomplish this on their own, while others may benefit from using specific approaches. Poston describes a number of these techniques (5):
stimulus control: identifying what environmental influences promote poor habits, and changing or replacing them.
self monitoring: e.g. using food diaries
cognitive restructuring: issues of poor self esteem need to be addressed. By changing how one thinks and feels about oneself, ones actions may then change. Therapists may be very beneficial in assisting with this challenging process.
stress management: many people use food to relieve stress or deal with emotions. More constructive techniques to address stress need to be learned and used. Again, therapists may be very helpful here.
social support: people who have more social support have better, more long-lasting weight loss results.
2) Exercise: The NHLBI highly recommends exercise for the management of obesity because it: "modestly contributes to weight loss...and may help with the maintenance of weight loss". The benefit of a "modest contribution" to weight loss should not be underestimated. Exercise decreases abdominal fat and improves one's fitness, both of which result in a decrease in cardiovascular risk (6). In fact, being physically fit may result in lower mortality rates than being sedentary, regardless of what one's weight are (5).
Recommendations for how much exercise is needed have varied over the years. At present, the goal to reach for is:
- At least 30 minutes of modest physical activity most days of the week
- Resistance training for 20-30 minutes twice a week, especially for women since they are at risk for osteoporosis
For one who does not exercise, one can build up slowly to this goal, starting with 30 minutes of accumulated physical activity (it can be broken up throughout the day into two or three shorter sessions) three times a week.
3) Nutrition: The marketing of weight loss diets has become a booming economic venture, especially in the United States. Frequently, the diet plans seem to contradict each other in terms of what foods are encouraged to be eaten or not eaten. This can lead to a frustrating situation for one who is attempting weight loss, as deciding which plan to follow can be confusing and can distract one from incorporating the basic principles of good nutrition into their life-long nutritional regimens.
The goal of a nutritional plan is not simply to achieve weight loss, but to maintain it and to promote good health. This means that the plan needs to be:
- Palatable, taking into account individual and cultural preferences
- Reasonably feasible to incorporate into one's life
- Acceptable for the long-term
- Balanced, including a variety of foods (i.e. not eating the same foods every day)
- Inclusive of appropriate supplements, including calcium and iron and fiber for most women.
- Result in a lower daily calorie intake than one was previously consuming. Most recommend a 500 kcal deficit (10).
A good portion of diets on the market do not meet all these criteria. The American Heart Association and the American College of Cardiology recommend a diet which is popularly referred to as the "Mediterranean diet." This includes foods which are rich in complex carbohydrates (whole grains), fish, fruits and vegetables and low in saturated fat and trans-fatty acids (6). There can be a fair amount of individual variability in how one chooses to incorporate these principles into their personal nutritional plans. For those who would prefer a more structured approach ("Just tell me what to eat!"), consulting a nutritionist to help them develop a more detailed diet would be helpful.
The Atkins diet is a popular diet which focuses on maintaining a very low intake of carbohydrates, and a relatively high intake of fat, including animal fat. Its main appeal is that it does seem to result in short-term weight loss. It's long term results, and its overall effect on the heart is not yet clear.(13) A recent article in JAMA suggests that the success of this type of diet is not due to its low carbohydrate content, but to its low calorie content and to the fact that people seem to stay on this diet longer. (14)
4) Drugs: The NHLBI recommend the use of weight-loss medication:
- As part of a comprehensive weight loss program
- For patients with a BMI of 30 and above
- For patients with a BMI of 27 and above with obesity-related diseases
- That lifestyle change must accompany the use of drugs
- That the patient is closely monitored
Though there are numerous prescription and non-prescription drugs which are used for weight loss, only two are FDA approved for long-term use: Orlistat (Xenical) and Sibutramine (Meridia).
Orlistat is a lipase inhibitor which results in weight loss by decreasing fat absorption. It has been found to result in an average weight loss of about 5-6 lbs more than with diet and exercise alone, and may result in an improved lipid profile and better glycemic control for diabetics (5). Its side effects are mostly gastrointestinal and vitamin supplementation is needed to replace fat-soluble vitamins. It may be an appropriate choice for fat-cravers.
Sibutramine is a norepinephrine and serotonin reuptake inhibitor which works by increasing satiety. It therefore would be most useful for people who feel hungry all the time. It can result in a dose-dependent weight loss and maintenance of weight loss greater than with diet alone. Like orlistat, it may also improve lipid profiles and glycemic control. It can result in increased blood pressure and pulse. Its effects, as well as those of orlistat, disappear when medication is discontinued and may result in a rebound weight gain.
A number of other drugs including zonisamide and recombinant variant of ciliary neurotrophic factor (which by-passes leptin resistance) are also being studied (15), (16).
5) Surgery: The theory behind bariatric surgery is that by decreasing stomach size, food intake can be controlled. Though it has been performed for years, the past year has seen an enormous increase in the number of surgeries performed, and demand continues to increase.
Bariatric surgery is effective in both short and long-term weight loss. The Roux-en-Y Gastric Bypass procedure (the most effective of a number of different procedures), results in 48-74% mean excess weight loss after five years, though the maximal weight loss is usually achieved by 2 years (17).
Currently, surgery is recommended for those with a BMI> 40, or those with a BMI>35 with co- morbidities.
Though obesity affects everyone, the effects on women are profound. As the primary caretakers of families, they are faced with the challenge of not only addressing their own health issues, but those of their children, spouses and parents. With obesity, disease follows, and women will be caring for sicker family members. Minority women and women from low socio-economic status are particularly affected. With their disproportionately high rates of obesity coupled with their disproportionately low rates of receiving appropriate medical care, they and the families they care for, will be facing a health crisis in the decades to come.
The economic, social and psychological burden of obesity on the individual and on society will continue to grow until the factors contributing to the increasing rates of obesity over the past two decades are identified and addressed. Though this article has focused on how an individual can approach obesity, society needs to develop a plan of action. Encouraging physical activity programs in schools and communities for children, developing cheap, healthful alternatives to fast food, providing better social and psychological support to those struggling with chaotic lifestyles, and redefining work load and the workplace so they are more compatible with maintaining healthy, balanced personal lives may be some strategies to consider.
We have seen that "treating" obesity is no small feat. Behavioral, dietary, and sometimes psychological changes need to be made. Even with these, results are hard to achieve and harder to maintain. Surgery is the single most effective weight loss technique for the very obese, but to rely on this as the best way to address obesity is drastic and unrealistic for the majority of the population which is overweight or mildly obese. Without a thorough evaluation of the environmental and societal facilitators of obesity and a commitment to modify them, the individual task to change one's life and one's body will continue to be a monumental one, and the obesity epidemic will continue to intensify.
- Giles T. Reducing the Risk of Cardiovascular Events Through Weight Loss. Medscape CME. University of Michigan 2002.
- National Task Force on the Prevention and Treatment of Obesity. Medical Care of Obese Patients: Advice for Health Care Professionals. Am Fam Physician 2002; 65:81-8.
- Lyznicki J, Young D, Riggs J et al. Obesity: Assessment and Management in Primary Care. Am Fam Physician 2001; 63:2185-96.
- Blackburn GL, Bevis LC. The Obesity Epidemic: Prevention and Treatment of the Metabolic Syndrome. Medscape. September 18, 2002.
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- Del Negro A. Take Weight Off Your Heart and a Load Off Your Mind. Medscape cardiology 7(1), 2003.
- Holt VL, et al. Body weight and risk of oral contraceptive failure. Obstet Gynecol. May 2002;99:820-7.
- Crane SS, et al. Association between pre-pregnancy obesity and the risk of cesarean delivery. Obstet Gynecol 1997;89:213-6.
- Blanco AT, Smilen SW, Doris Y et al. Obstet Gynecol. Jan 1998;91(1):97-102.
- NHLBI. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: Executive Summary.
- Serdula MK et al. Weight loss counseling revisited. JAMA. April 9 2003;289(14)1747-1750.
- Heshka S et al. Weight loss with self-help compared with a structured commercial program. JAMA. 2003;289:1792-1798.
- Schooff M. Are low-fat diets better than other weight-reducing diets in achieving long-term weight loss? Am Fam Physician. February 1,2003.
- Bravata D. Efficacy and safety of low-carbohydrate diets. JAMA. 2003;289:1837-1850.
- Gadde K. Zonisamide for weight loss in obese adults. JAMA. 2003;289:1820-1825.
- Ettinger MP. Recombinant variant of ciliary neurotrophic factor for weight loss in obese adults. JAMA. 2003;289:1826-1832.
- Mitka M. Surgery for obesity. JAMA. 2003;289:1761-1762.
Dedicated to Women's and Children's Well-being and Health Care Worldwide