Special Populations: Preventing Obesity and Type 2 Diabetes in Youth: Call to Action
Tom LaFontaine, PhD, CSCS, NSCA-CPT, FACSM
Boone Hospital Center/PREVENT Consulting Services, Columbia, Missouri
THIS COLUMN IS INTENDED TO present information on strength and conditioning in special populations. Two particularly special populations that come to mind are youth and older adults. The older adults of this nation command respect and admiration for, among many other things, meeting the challenges they faced during World War II and the cold war to preserve freedom and liberty at home and abroad. Strength and conditioning specialists and personal trainers should welcome the opportunities to provide services to these remarkable heroes and heroines. At the front end of the lifespan, the youth of our nation require our attention because the future of the nation and the world literally rests in their hands. President John F. Kennedy once stated that the “strength of a nation is as only as good as the physical fitness of it's citizens.” Two problems that have increased in epidemic proportions since JFK was president among American adults and youth are obesity and type 2 diabetes mellitus. The purpose of this article is twofold: (a) to briefly review recent data that describe the epidemic trends in obesity and type 2 diabetes mellitus in the U.S. and their causes, and (b) to present a call to action to NSCA members to do their part to reverse these trends.
The Twin Epidemics of Obesity and Type 2 Diabetes—“Diabesity”
The prevalence of obesity among U.S. adults (body mass index [BMI] greater than 30) rose from 12 to 20% between 1990 and 2000 (5). In addition, in 2000, 61% of adults were overweight. McTigue et al. (4) recently reported the results of the National Longitudinal Study of Youth. On the basis of 12 self-reports of height and weight from 9,179 youth, studied between 1981 and 1998, it was concluded that 26% of men and 28% of women were obese by ages 35–37 years. Obesity onset was 2.1 and 1.5 times faster for Black and Hispanic women, respectively. In all racial and ethnic groups, being mildly or moderately overweight by age 20–22 years was linked significantly with a substantial incidence of obesity by age 35–37 years. It is estimated that 77% of overweight teenagers will become overweight adults compared with only 7% of normal-weight teenagers. Early identification and intervention among youth at risk for obesity is crucial to the prevention of obesity and type 2 diabetes.
Another study of 8,270 children aged between 4 and 12 years reported that between 1986 and 1998 the prevalence of obesity, defined as greater than the 85th percentile for age and gender, increased by more than 120% among African-American and Hispanic children and by more than 50% among White children (8). Approximately 25, 38, and 36% of White, Hispanic, and African-American children, respectively, were above the 85th percentile for their age and gender. These findings represent nearly a tripling of obesity among children since the 1960s.
The prevalence of self-reported diabetes among adults increased from 4.9% in 1990 to 7.3% in 2000 (5). Considering that many cases are undiagnosed, it is likely that greater than 10% of American adults have diabetes. Considering the high prevalence of impaired fasting glucose or prediabetes (fasting blood glucose of 110–125 mg/dL), probably 15–20% of U.S. adults have diabetes or prediabetes. Overall, since the 1950s, there has been a ninefold increase in type 2 diabetes in the United States.
The link between obesity and type 2 diabetes is well defined. Studies show that BMI is the strongest predictor of diabetes (2).
In the past 5 years there has been a 10-fold increase in the number of children with type 2 diabetes (6). In fact, 40–50% of cases of diabetes among children are of type 2. Recently, Sinha et al. (7) studied the prevalence of impaired glucose tolerance among children and adolescents with marked obesity (7). Among 55 obese children (BMI of 32 in boys and 30 in girls), 4–10 years of age, impaired glucose tolerance was found in 25%. Among 112 obese adolescents (BMI of 37 in boys and 34 in girls), 21% had impaired glucose tolerance and 4% had previously undiagnosed type 2 diabetes. Impaired glucose tolerance was associated with insulin resistance, whereas beta-cell function was still preserved, but adolescents with type 2 diabetes showed evidence of beta-cell failure. The future ramifications of these findings are sobering, considering the high risk of vascular, renal, eye, and neurological complications of diabetes.
The Effect of this Trend
Over 300,000 deaths each year are attributable to overweight and obesity (5). Obesity is related to increased risk of several chron ic diseases listed in Table 1 .
The economic costs of obesity are over $117 billion (5). Diabetes and its complications account for $1.00 of every $7.00 spent on health care. Obesity costs U.S. businesses more than $13 billion. According to a RAND corporation study, obesity is associated with more chronic health problems than is tobacco use (9). One in 5 children in the U.S. have at least one risk factor for coronary artery disease, and studies show that 1 in 6 teenagers have evidence of coronary atherosclerosis (10). These trends are alarming and suggest the possibility of a future decline in health status and longevity.
The Causes of the Diabesity Epidemic
Although genetics and family history play an important role in the etiology of obesity, human genes do not change in just 1–3 decades! Behavioral and environmental factors—specifically poor nutrition and physical inactivity—are clearly the leading causes and targeting these factors provides the best opportunities for prevention!
Poor nutrition in the “land of plenty” is a major problem in the United States.
The typical American diet is high in calories and fat and low in nutrients.
Fast food is widely available and consumption and portions continue to “grow.”
Fewer meals are eaten at home.
One in 5 adults and fewer youth consume 5 or more fruits and vegetables per day.
It is estimated that Americans are eating 167 more calories per day than they were in the 1960s—equivalent to a 17-lb weight gain per year.
Vending machines selling high-sugar soft drinks, high-fat and sweet snacks are common in schools and workplaces, and school lunches are still >30% fat.
Per capita consumption of soft drinks increased from 27 gal in 1972 to 44 gal in 1992.
Low-fat milk, juices, water, and healthy snacks are essentially unavailable in many schools or certainly far less accessible.
Food is “super-sized” and virtually everywhere—junk food can now be ordered while dispensing gas at some service stations.
Whole grains and legumes are rarely consumed by U.S. adults or children.
Physical inactivity is rampant in the U.S.
Only 2 states, Illinois and Texas, require daily physical activity in schools.
By 9th grade, 70% of girls and 50% of boys no longer participate in vigorous exercise.
The average child spends 20–30 hours per week watching TV or playing computer or video games.
A recent study showed that preschool children (ages 1–5 years) who had a TV in their room watched 4.6 more hours of TV per week and were twice as likely to be overweight (1).
Many communities lack suitable and safe places for exercise and nonmotorized commuting such as green space, sidewalks, trails, adequate street lighting, etc.
Modern culture has engineered physical activity out of our daily lives while allowing food manufacturers and fast food restaurants to indiscriminately market high-fat, high-calorie, high-sugar, and high-sodium and low-fiber, low-nutrient-dense foods to our youth. It is time that we, as professionals in the fitness and health promotion industry, take action to help reverse these disturbing and frankly depressing trends.
A Call to Action for All NSCA Members
Eighty percent to 90% of type 2 diabetes is due to overweight and physical inactivity. Among approximately 3,300 at-risk adults who participated in a 3-year study funded by the National Institutes of Health it was found that a weight loss of 5–7%, 30 minutes of physical activity, 5 days per week, and a low-fat, high-fiber diet reduced the risk for type 2 diabetes by 58% (3). Thus, clearly obesity and type 2 diabetes are preventable. A concerted action among governments, schools, health and fitness professionals, and concerned citizens can avert a major health crisis in the next 20–30 years. At the present rate of “growth” that is prevalent in the U.S., nearly everyone will be overweight by the year 2030.
It is imperative that we, as leaders in the fitness and health industry, be role models. An optimal adult BMI is less than 25. Unless your body fat is <22% for women and <15% for men, you should strive for a BMI of <25. But if you are overweight, just 5–10% weight loss can markedly improve risk factors for diabetes, hypertension, and cardiovascular disease. We all need to model sound eating habits by consuming a balanced diet consisting of reasonable portions and “colorful” selections from all food groups. We need to eat 5–9 servings of fruits and vegetables per day, 6–11 whole-grain servings per day, and choose nonanimal protein sources such as soy, nuts, and legumes more frequently. We need to consume less of red meat and more of cold-water fish. We need to be sure to engage in 30 minutes or more of daily physical activity, including some time devoted to resistance training and stretching. We, of course, must avoid tobacco products and consume no more than 1–2 alcoholic beverages per day. We should choose water, low-fat milk, fruit juices, and tea over high-sugar, high-fat drinks. Other things we, as professionals in the fitness and health industry, can do to help reverse these distressing trends in the prevalence of obesity and Type-2 diabetes among youth include:
Support legislation to curb the proliferation of high-fat, high-sugar products.
Support legislation to restrict promotion of “junk” food to youth.
Support legislation to increase physical education in schools.
Support proposals to improve sidewalks, pedways, and trails in local communities.
Work with community organizations to make physical activity and health education programs more available to youth, particularly youth at risk.
Develop and deliver programs for youth fitness and health education.
Market your services to local industries to make opportunities for physical activity at the worksite available.
Become an active educator in your area by presenting at local service and other organizations on health and fitness.
Expand your scope of practice by working with nonathletic youth, particularly those who are overweight and are at risk of obesity and diabetes.
Most of all be a role model and practice the healthful behaviors we want our youth to practice.
These are a few things we all can do to reverse the diabetes and obesity epidemic and assure a healthy future for our youth. I believe that NSCA professionals have an opportunity to expand their reach by working with at-risk youth to prevent obesity and type 2 diabetes. I encourage NSCA members to do their part to improve the health and fitness of our youth. Let me close with a quote from James Kent, “nothing is so potent as the silent influence of a good example”! There is no better reward than to know that you, by your personal actions and behaviors, influenced a young person to lead a healthy and fit life.
References
1. Dennison, B.A., J.A. Erb, and P.J. Jenkins. Television viewing and television in bedroom associated with overweight risk among low-income pre-school children. Pediatrics. 109:1028–1035. 2002. [PubMed Citation]
2. Hu, F.B., J.E. Manson, M.J. Stampfer, G.A. Colditz, G. Liu, C.G. Solomon, and W.C. Willett. Diet, lifestyle, and the risk of type 2 diabetes mellitus in women. N. Engl. J. Med. 345:7990–7997. 2001.
3. Knowler, W.C., E. Barrett-Conner, S.E. Fowler, R.F. Hamman, J.M. Lachin, E.A. Walker, and D.M. Nathan. Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N. Engl. J. Med. 346:393–403. 2002. [PubMed Citation]
4. McTigue, K.M., J.M. Garret, and B.M. Popkin. The natural history of the development of obesity in a cohort of young U.S. adults between 1981 and 1998. Ann. Intern. Med. 136:857–864. 2000.
5. Mokdad, A.H., B.A. Bowman, E.S. Ford, F. Vincor, J.S. Marks, and J.P. Koplan. The continuing epidemic of obesity and diabetes in the United States. JAMA. 286:1195–1200. 2001. [PubMed Citation]
6. Pinhas-Hamiel, O., L.M. Dolan, S.R. Daniels, D. Standiford, P.R. Khoury, and P. Zeitler. Increased incidence of non-insulin dependent diabetes mellitus among adolescents. Pediatrics. 128:608–615. 1996.
7. Sinha, R., G. Gisch, B. Teague, W.V. Tamborlane, B. Banyas, K. Allen, M. Savoye, V. Reiger, S. Taksali, G. Barbetta, R.S. Sherwin, and S. Caprio. Prevalence of impaired glucose tolerance among children and adolescents with marked obesity. N. Engl. J. Med. 346:802–810. 2002. [PubMed Citation]
8. Strauss, R.S., and H.A. Pollack. Epidemic increase in childhood overweight, 1986–1998. JAMA. 286:2845–2848. 2001. [PubMed Citation]
9. Sturm, R., and K.B. Wells. Does obesity contribute as much to morbidity as poverty or smoking?. Public Health. 115:229–235. 2001. [PubMed Citation]
10. Tuzcu, E., S.R. Kapadia, E. Tutar, K.M. Ziada, R.E. Hobbs, P.M. McCarthy, J.B. Young, and S.E. Nissen. High prevalence of coronary atherosclerosis in asymptomatic teenagers and young adults: Evidence from intravascular ultrasound. Circulation. 103:2705–2710. 2001.
Tom LaFontaine, Column Editor
Article found on www.nsca-lift.org
