Exercise is far more crucial than eating less to winning the battle of the bulge, a leading obesity researcher told a national convention of health experts in Denver last week.
“I think diet is important, but the key to weight loss is activity,” said James O. Hill, co-founder of the “America on the Move” program, which encourages people to walk an average of 10,000 steps per day – about 5 miles.
“We tell people, If you’re not prepared to increase your physical activity, don’t try to lose weight, because you won’t keep it off,” said Hill, who directs the Center for Human Nutrition at the University of Colorado Health Sciences Center.
He made the comments during a symposium at the annual meeting of the American College of Sports Medicine, which ended Saturday. Some 5,000 doctors, scientists, educators, fitness trainers and physical therapists attended the gathering at the Colorado Convention Center.
One reason dieting doesn’t keep weight off over the long term is that “you’re fighting biology,” Hill explained.
“If you’re burning 3,000 calories a day (being active), eating 3,000 calories to achieve a balance is pretty satisfying. But if you’re expending 1,800 calories (being sedentary), trying to restrict your intake to just 1,800 calories is hard, and very few people are successful at it,” he said.
“Most of the population is gaining weight over time, at a rate of 1 or 2 pounds a year.”
Tracing the rise in obesity over the past 25 to 30 years, Hill said it’s unclear from the limited data available whether Americans’ bulging waistlines are due mainly to shifts in eating patterns or to changes in activity levels. But there is a clear link between weight gain and inactivity, he stressed.
In Colorado, where research has found that people walk an average of about 6,550 steps per day, about 16 percent of the population is classified as obese. By comparison, in Tennessee, where the average is about 4,650 steps per day, the obesity rate is 25 percent.
More tellingly, Hill said, obesity is almost unknown among Amish men and women, who live a pre-industrial lifestyle and walk an average of 16,000 steps per day – about 8 miles.
As further evidence of the role of exercise in keeping weight off, he cited the roughly 5,000 people now included in the National Weight Control Registry, which is limited to those who have maintained at least a 30-pound loss for a minimum of one year.
The typical participant, Hill said, has lost about 60 pounds and kept it off for five years, in part by burning an average of 2,700 calories per week through physical activity – mainly walking. That’s a little more than 380 calories, or 7,600 steps, or 3 1/2 miles, per day.
Staff writer Jack Cox can be reached at 303-820-1785 or jcox@denverpost.com.
