The Overweight-Obesity Global Dilemma:
The Biggest Universal Risk To Health Worldwide
The latest estimates are staggering: 1.7 billion people worldwide are overweight or obese. The London based International Obesity TaskForce said the revised figure -50% higher than previous estimates- reflects a deliberate ignorance on the part of most governments in facing one of the biggest universal risks to health worldwide.
In the United States, obesity is the second leading cause of preventable deaths. According to the American Obesity Association, about 69 million Americans are overweight and 51 million are obese. These numbers have been rising steadily, translating to 61% of U.S. adults of the age 20 years and over are overweight, and 26% are obese. Annually, overweight/obesity causes at least 300,000 excess deaths annually in the US, burdening the nation with a healthcare tab of more than $100 billion each year. The nation's military is not immune from the obesity epidemic sweeping the US. Despite the rigors of basic training and regular field exercises, 54% of military personnel are overweight and 6.2% are obese. Obesity affects military performance: obese soldiers have higher risk of heat injury and increased musculoskeletal injuries.
In Europe, an estimated 20% of residents are obese and many more are overweight. Professor Andrew Prentice from the London School of Hygiene and Tropical Medicine cites obesity as the single most greatest threat to the gains in longevity made during the last 100 years. He observes that people are getting fatter, not taller, at a much younger age. Thanks to high-fat fast-food diets, exercising less, and spending more time indoors in front of computers and televisions, adolescents are packing on the pounds at younger and younger ages, and are likely to remain overweight-obese into adulthood. As a result, some British nutritionists expect many parents to outlive their children. In Britain, the National Audit Office reports that about 30,000 people die of obesity-related causes each year, cutting short their lives by about 9 years.
Newest recommendations from the World Health Organization (WHO) may add another half billion to the tally of overweight obese people worldwide. A WHO expert group found that a lower body mass index threshold (23.3, rather than 30 for non-Asian populations) can put Asians at an increased risk for obesity-related health risks. This prompted the group to propose that WHO adopts a revised definition of obesity that is specific to Asian populations to accommodate the body mass index difference. That would mean that of the world's 6.3 billion residents, 2.2 billion - over 1 in 3 - are overweight or obese.
Overweight-Obesity Shortens Longevity
An analysis of data of 3,457 participants in the Framingham Heart Study from 1948 to 1990 found that being overweight at middle-age can dramatically shorten life expectancy. Non-smokers who were overweight (but not obese) lost an average of 3 years off their lives. Obese people die even sooner. Obese female non--smokers lost an average of 7.1 years, while non-smoking obese men lost 5.8 years. As a risk factor, overweight-obesity ranks as deleterious to life expectancy as smoking.
Fortunately, there is some encouraging news for those who are overweight or obese and try to lose weight. They may live longer than those who do not try to shed their excess pounds. In a study of 6,000 obese and overweight people age 35 and older who were followed for nine years, Dr. Edward Gregg of the Centers for Disease Control and Prevention (Georgia) found a 24% lower death rate in overweight-obese men and women who lost weight intentionally than in people whose weight remained steady during the course of the study. Even people who were trying to lose weight but did not succeed had a lower death rate. Dr. Gregg suggests that even modest attempts at physical activity and improving diet and nutritional intake could be beneficial even if they do not result with weight loss.
Quantifying Overweight and Obesity Body Mass Index
Body mass index:
(BMI) is the measure of body fat defined as body weight divided by the square of your height. BMI can be calculated by multiplying weight in pounds by 703, dividing the result by height in inches, and finally dividing that result by height in inches again. The National Heart, Lung, and Blood Institute's (NHLBI) website (www. nhlbisupport.com/bmi/) operates an online BMI calculator and makes BMI tables available as well.
For the US population, the NHLBI's 1998 Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity categorizes BMI as follows: •Underweight = <18.5,
• Normal weight = <18.5, • Overweight = 25-29.9, • Obesity, Class 1 = 30-34.9 • Obesity, Class 2 = 35-39.9, • Extreme Obesity, Class 3 = 40+
Because BMI may underestimate body fat in older persons and those who have lost muscle mass, and it may overestimate body fat in athletes and those with muscular build, there are two additional assessments for determining overweight-obesity.
Waist Circumference
Determine your waist circumference by placing a measuring tape snugly around your waist.
Waist circumference indicates abdominal fat, a predictor associated with heart disease risk. If your waist measure over 40 inches for men and 35 inches for women, you are at increased risk to develop heart disease, high blood pressure, diabetes, and certain cancers.
Additional Risk Factors
Those with extra weight need to be mindful of additional risk factors that can increase their risk of developing obesity-related diseases. The risk factors to watch include: • high blood pressure (hypertension), • high LDL-cholesterol, • low HDL-cholesterol, • high triglycerides, • high blood glucose, • family history of premature heart disease, • physical inactivity, • cigarette smoking
If the individual's BMI is 25+ and s/he has two or more of the above risk factors, weight loss (even a reduction of just 10% of current weight) will help to lower the risk of developing obesity-related diseases. Adults who are overweight, do not have a high waist measurement, and have fewer than two risk factors may benefit from a program to prevent further weight gain.
Health Risks of Being Overweight- Obese
Comparing Americans with a BMI of 18.5 to 24.9 vs. those with a BMI of 40+, obese adults face: • 7.37 times greater risk of becoming diabetic • 6.38 times greater risk of having high blood pressure • 1.88 times greater risk of having high cholesterol levels • 2.72 times greater risk of developing asthma • 4.41 times greater risk of developing arthritis.
As Professor Phillip James, chairman of the International Obesity TaskForce remarked, "It is clear that ... we are witnessing a real health tragedy unfolding."
Diabetes
Overweight people are twice as likely to develop type 2 (adult-onset) diabetes as those who are not overweight. Type 2 diabetes itself is a major cause of heart disease, kidney disease, stroke, and blindness.
Heart Disease and Stroke
The leading causes of death and disability among American men and women, being overweight makes people susceptible to high blood pressure, high cholesterol and elevated triglycerides. Each of these conditions can cause plaques to form, clogging the arteries that feed the heart (leading to heart disease) and brain (leading to stroke). Additionally, overweight can cause angina (chest pain caused by insufficient oxygen to the heart), which can lead to sudden death from heart disease or stroke in the absence of symptoms.
Cancers
Several types of cancer are specifically associated with overweight. Women who are overweight are prone to cancers of the uterus, gallbladder, cervix, ovary, breast, and colon. In a report published earlier this year (2003), Dr. Kelly Evenson and colleagues at the University of North Carolina found that women with high BMI at the start of a 25-year long study were 50% more likely to die of cancer than women who were not overweight
Overweight men are at greater risk for developing cancer of the colon, rectum, and prostate. Dr. Evenson's study also found that fittest men were half as likely to die from cancer during the 25-year study than their less-fit counterparts.
Pancreatic cancer is the fifth deadliest cancer in the United States and the sixth deadliest in Europe. The disease is difficult to detect and control due to its vague symptoms and because the location of the pancreas makes it examinations. Dr. Debra Silverman and colleagues from the National Cancer Institute (Maryland) found that overweight people have a 70% greater chance of developing pancreatic cancer. By comparing the overweight subjects to a matched group of healthy-weight counterparts, Dr. Silverman's team discovered that a lack of exercise and low intake of antioxidant rich vegetables (broccoli, cauliflower, cabbage, and Brussel sprouts) by the overweight subjects were responsible for up to 60% of the diagnosed cases.
In a study published in 2001, more than 28,000 obese Swedish patients were followed for 29 years. The researchers compared the incidence of cancer in these patients with the incidence in the general Swedish population. Thirty-three percent more cases of cancer occurred among the obese men and women than in the general population. The obese patients had increased risk for Hodgkin's disease (among men) and cancers of the endometrium, kidney, gallbladder, colon, pancreas, bladder, cervix, ovary, and brain. Non-Hodgkin's lymphoma was higher in obese women, and elevated rates of cancers of the liver, small intestine, and larynx were also found.
Sleep Apnea
A condition that can cause a person to snore heavily and stop breathing for short periods of time during sleep, sleep apnea is more prevalent in the overweight and obese. The condition often causes daytime sleepiness (making the person prone to accidents) and is a cause of heart failure. Weight lass usually improves sleep apnea.
Osteoarthritis
Osteoarthritis a common joint disorder that often affects the joints in the knees, hips, and lower back. Extra weight increases the risk of osteoarthritis by placing extra pressure on these joints and wearing away the protective cartilage. Weight loss can decrease joint stress and improve symptoms of this condition.
Gallbladder Disease
Gallbladder disease and gallstones are common in those who are overweight. Additionally, rapid weight loss or loss of a large amount of weight can increase the chances of developing gallstones. People who are overweight are recommended to follow a program of modest, slow weight loss (one pound a week), which reduces the chances of gallstones.
Metabolic Syndrome (Syndrome X)
Forty-seven million American adults - more than 1 in 5 -- have metabolic syndrome, a disorder characterized by a cluster of health problems including abdominal fat, high blood pressure, poor lipid profiles, and high blood sugar. Metabolic syndrome greatly increases the risk of heart attacks and stroke. It is, fortunately, as Dr. Margo Danke at University of Texas Southwestern Medical Center described, "one syndrome that is exquisitely lifestyle-sensitive-it’s an area where we can get people to pay attention and there’s big rewards." Metabolic syndrome can be controlled or reversed by carrying overeating, increasing exercise, and adopting less stressful lifestyles.
Lower Intelligence
Dr. Merrill Elias and colleagues at Boston University (Massachusetts) found that obese men may experience a decline in thinking ability - especially memory and learning.
In the study, researchers analyzed information gathered over an 18-year period from 551 men and 872 women who participated in the Framingham Heart Study. They found that obesity and high blood pressure -- both alone and in combination - had a negative effect on brain function, but only in men. Expert colleagues commenting on Dr. Elias' study suggest that obesity may impair the ability for blood to reach the brain, thereby damaging brain function, much like high blood pressure and high cholesterol can also do.
Current Interventions
Presently, the most effective non-pharmacological options for weight loss involve 30-60 minutes of daily physical activity, adopting a diet high in whole-grains, fruits, and vegetables, and adopting a less stressful lifestyle (to avoid overeating or eating when not hungry). In cases where the individual's weight poses a high health risk, pharmacotherapy (appetite suppressants) may be employed. For those 70,000 Americans whose weight poses an extremely high health risk, surgical intervention (such as stomach bypass or stapling) may be appropriate.
Interventions on the Horizon
In the words of Professor Arne Astrup, president-elect of the International Association for the Study of Obesity (IASO), “There is a global obesity epidemic which underpins the increasing levels of non-communicable diseases which are forecast to explode in the next 20 years. It is vital that we take a more serious approach to the treatment of the huge numbers who are obese, as well as introducing effective measures to prevent the problem from getting worse."
Novel Weight Loss Drugs
The next blockbuster drug, following in Viagra’s footsteps in terms of brand recognition and popularity, is anticipated to be an obesity-busting drug that will help men and women beat their battle with the bulge. With a US market worth $1 billion annually, and a worldwide market worth over $20 billion, the stakes are high and the potential payoffs even higher.
The fat burners and fat-blockers that made it to market in the past two decades fell short of their anticipated successes. Today, drug companies are combining neurological and biochemical drugs with natural elixirs, seeking to create a sense of satiation while reducing appetite
Another wave of future drug development for obesity is the Human Genome Project. In just one year, IntegraGen (www.integragen.com) completed gene mapping for obesity and identified a druggable target. Initially, the company's Genome Hybrid Identity Profiling technology platform was applied to compare the whole Gnome of family members suffering from obesity. As a result, IntegraGen found the precise location of three disease-related loci in only four months. The researchers then identified several mutations in a gene associated with the obesity disease phenotype, and continued onward to validate the genetic relevance with a wider patient population. In the end, IntegraGen found that the gene encodes for a G protein-coupled receptor, which is involved in energy metabolism, and thus could turn out to be a major new druggable target for the treatment of obesity.
The Stomach Pacemaker
Gastric stimulation is a new therapy for the treatment of obesity, involving the delivery of mild electrical signals to the stomach wall. The objective of gastric stimulation is to change the motor activity of the stomach to induce early satiety, thereby causing the individual to eat less and lose weight.
Transneuronix International GmbH (Germany) (www.transneuronix.com) pioneered the development of the Implantable Gastric Stimulation (IGS) system. The device is approved for use in Europe, where patients have been consistently able to achieve good weight loss thus far.
The IGS device consists of a long flexible wire bearing an electrode, attached to a metal case (the size and thickness of a pocket watch) that contains a battery and electronic controllers. On an outpatient basis, the electrode is laparoscopically implanted into the muscle around the stomach and the case is inserted under the abdominal skin The device is then programmed for various parameters to optimize its settings for the particular patient Once activated by the physician, the IGS delivers high-frequency electrical pulses to the patient's stomach. After a short period-of modest postoperative restriction to promote good recovery, patients are not expected to experience any decrease in their ability to carry out everyday activities.
The device is now undergoing human trials in the United States, conducted by Transneuronix Incorporated (New Jersey) and lead researcher Dr. Scott Shikora of the Obesity Consult Center at New England Medical Center (Massachusetts). The Transneuronix IGS device could be the US market and available to the public within 3 years.
Concluding Remarks
On the celebration marking fifty years since the discovery of DNA, James Watson remarked in an interview with Time magazine that "The biggest medical dilemma facing most humans may soon be our masses of fat. One would hope that as we begin to dissect hunger at the molecular level, we can control our weight with safe pills. People can't resist food. So we may need science to save us from our human nature."
With biotech pioneers such as IntegraGen and Transneuronix on the cutting edge of obesity interventions and pharmaceutical giants vying to launch the ultimate anti-obesity drug, it would seem that science has heard our call for action. The next decade of obesity research will undoubtedly be filled with insights never before possible, thanks to the completion of the Human Genome Project in April 2003.