Jun 2 2005
Advertisements on television and in newspapers consistently hype the latest diet fads. News reports comment on the latest research about the negative effects of obesity on Americans.
The President's Council on Physical Fitness and Sports promotes the healthy effects of exercise. Yet, even with these and other efforts, the rate of increase in overweight and obese Americans continues to climb. According to University of Missouri-Columbia biomedical researchers Frank Booth and Simon Lees, every U.S. child and adult will be obese by 2044 and 2058, respectively, if the current progressive rise continues.
"If all the work we are doing to promote physical fitness is working, than why does the problem continue to get worse," said Booth, who gave the Joseph B. Wolffe Memorial Lecture at the American College of Sports Medicine's annual conference today. "We have increased sedentary activities for children by 4.5 times since 1950. Children and adolescents now spend 45 hours each week watching television, working on the computer, playing video games or watching movies.
In his lecture, Booth cited statistics that demonstrated a three- to fourfold increase in the percentage of overweight U.S. children and adolescents since the mid-1980s. Booth believes the increase in obesity is due to an incompatibility between human genes and societal pressures. Human genes evolved to support a great deal of physical activity, yet in the last 20 years, physical activity has decreased dramatically in the United States, Booth said.
In a recent study using rats, Booth found that a 48-hour period of inactivity can lead to a large increase in the amount of fat and the size of fat cells in the body. In a similar study, Booth found that insulin sensitivity decreases when a body is inactive for two days. This decreased insulin efficiency may be a precursor to diabetes and other related diseases. Both studies were published in The Journal of Physiology.
According to Booth, other problems associated with inactivity include:
- Earlier death – 20 years ago, the U.S. population ranked first in longevity on the planet. Today, American women rank 19th and American men rank 28th.
- Earlier onset of adult, or Type 2, diabetes – Increasing numbers of children are getting Type 2 diabetes. The Centers for Disease Control predict that the number of Type 2 diabetes cases in the United States will triple to 39 million by 2050.
- Onset of different types of cancer – other research has linked inactivity to breast cancer, colon cancer and pancreatic cancer.
According to Booth, decreasing the amount of activity by less than four minutes each day can result in a person gaining one pound of fat in a year. In his lecture, Booth challenged scientists and the public to enact a series of policies to counteract the inactivity problem.
"We scientists need to stop labeling control groups in our studies as those groups who are inactive," Booth said. "In studies today, researchers are examining the effects of exercise on a number of diseases. In effect, they are using sick people as the control group and using the people who exercise as the anomaly. This needs to change. The public also needs to start taking responsibility for childhood inactivity. Children are not mature enough to make informed decisions about their eating habits and activity without instruction from adults."
Booth also recommended that doctors start asking their patients about their activity levels, much like they do about their drinking and smoking activities. Physical activity levels should be monitored by a health professional to prevent chronic disease before they occur, Booth said.