United Press International surveyed 84 specialists for a 15-part series weighing in on the causes, consequences and costs of a global gain in girth and measures to curtail the corpulence. Part 5 steps up to the exercise plate in a game-plan to lose, and level, weight.
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SAN FRANCISCO (UPI) -- Want to whittle down your weight? Try walking off more calories than you can chew.
The pedestrian principle, dating back 24 centuries or more, sits well with modern-day specialists trying to mobilize forces against a sedentary lifestyle many blame, at least in part, for the super-sizing of America and other bloated parts of the globe.
"We're eating a lot more calories, and we're exercising a lot less; it's not a big mystery why we're getting fat," Gail Woodward-Lopez, a University of California, Berkeley, expert on obesity and overweight prevention, said in a telephone interview.
"There is only one way to become obese and that is to develop a chronic energy imbalance, whereby energy intake (diet) exceeds expenditure (physical activity)," agreed Peter Katzmarzyk, professor of physical and health education at Queen's University in Kingston, Ontario.
If the objective calls for keeping poundage on an even keel, nothing short of sustaining an equilibrium will suffice.
"Frankly, it all comes down to the calories going in must be on balance with the calories going out -- you are what you eat minus what you excrete," said registered dietitian Mara Vitolins, assistant professor of public health sciences at the Wake Forest University School of Medicine in Winston-Salem, N.C.
Recognition of this inalienable interlink resonated with the Greek medical sage Hippocrates some 2,400 years ago. "Those desiring to lose weight should perform hard work before food," the father of Western medicine advised. "They should take their meals after exertion and while still panting from fatigue."
Relaxed over the generations, the modern-day message nevertheless runs with the same concept.
"Total calories impact the balance equation -- trying to match energy in with energy out," said registered dietitian Sylvia Moore, professor of family medicine and director of the Division of Medical Education and Public Health at the University of Wyoming in Laramie.
"What we eat also plays a role," said Moore, a principal investigator in a four-year, $4.3 million study of rural health behaviors under way at the University of Washington in Seattle. "I like to tell clients to think of their bodies as highly complex vehicles that need premium fuel rather than the cheapest standard grade available."
As with any moving machine, the body's engine needs to be revved up regularly to keep it in optimal operating condition.
In a study of 3,000 battlers of the bulge, James Hill, director of the Center for Human Nutrition at the University of Colorado Health Sciences Center in Denver, found the undefeated followed a slow but steady course of staying active.
Hill, developer of "Colorado on the Move" and a national version of the program that uses step counters to avert weight gain, noted only those who sustained a stepped-up level of physical exertion beat the scale in the long run.
"The best way to (lose weight) is to reduce calorie intake and increase activity level," said nutritional scientist Thomas Wolever of the University of Toronto in Canada.
Any surplus of sustenance bankrolls wads of extra girth. As an example, indulging in 100 calories -- the equivalent of about a third of a hamburger -- a day more than needed will beef up the body by 10 pounds a year. A half hour of moderate daily activity -- from gardening and golf to bowling and boating -- could grind up the excess bulk.
"When we maintain our weight -- neither gain nor lose weight -- we are in energy balance," said Nancy Amy, associate professor of nutritional sciences and toxicology at UC Berkeley. "That means we are exercising at an appropriate level compared to how much we are eating."
Keeping on track paves the way to fitness, which the President's Council on Physical Fitness and Sports defines as a fine tuning of the body that hones its major parts -- including the heart, lungs, muscles and bones -- for optimal physical performance, which, in turn, can have a bearing on such mental capabilities as alertness and emotional stability.
"For good health, doctors are now promoting 'metabolic fitness,' which is a combination of good glucose (blood sugar) control, good cholesterol levels and blood pressure," Amy said. "All of these measures are affected by physical fitness."
Exercise steps into the equation because simply cutting back on calories may not produce optimal results.
"Ideally, weight loss would all be fat, and muscle would be spared or even gained," Moore explained. "This will require activity."
How much depends on numerous factors, including age, sex, heredity, metabolism and eating and exercise habits. For example, according to the American Heart Association, a 100-pound bicyclist pedaling at 6 miles per hour will pump off some 160 calories during a 60-minute cruise, compared to 240 calories blown off by a 150-pound rider and 312 calories by one who tips the scale at 200 pounds. Rev the speed up to 12 mph, and the calories crushed will jump to 270, 410 and 534, respectively, for those individuals. Similarly, jogging at 7 mph will bounce off 610, 920 and 1,230 calories, while running at 10 mph will leave 850, 1,280 and 1,664 calories in the dust.
"Keep in mind the following relationship," said Australian fitness guru and researcher Shane Bilsborough. "An hour of exercise burns about 1,500 kilojoules (358 calories); a 100-gram (3.5-ounce) block of chocolate contains 2,200 kJ (526 calories) of food. It is important we all have some idea of the energy balance equation without actually counting calories."
Thus, half an hour of pumping on a stationary bicycle burns off some 250 calories, enough to make short shrift of a hot dog (240 calories), though not a hamburger (275 calories). To drop 1 pound of body bulk -- equal to about 3,500 calories -- in one week, the weight watcher would have to consume 500 fewer calories than he or she metabolized every day for seven days.
"If you drink several cans of soda (at 100 calories to 200 calories a pop) a day, which many people routinely do, that's an easy 500 calories a day," said Dr. Linda Stern, an internist at the Philadelphia Veterans Affairs Medical Center. "If you consider 1 pound of fat equals 3,500 calories, you can see you'll drink the equivalent of 1 pound of fat a week, so you can gain 1 pound a week just from drinking beverages, which don't even satiate the way food does."
To work it off, a medium-size adult would need to walk more than 30 miles. The trek could be stretched out over several days and broken down into smaller, more manageable jaunts, provided calorie consumption were held in check. Tossing in any extra fuel, particularly fat-laden food, would make the burn-off effort go up in smoke.
"People fail to understand that the average person can only burn about 20 grams of fat in 1 hour," Bilsborough said. "In fact, when it comes to exercise (which humans are just not doing), it is easier to burn carbohydrates (glucose) than it is fat."
Difficult to metabolize, fat in particular requires an extra pound of cure.
"Dieting alone can only rid the body of 300 grams to 400 grams a week," Bilsborough stated. "Fat loss needs exercise as its partner and needs to be sustainable in the long run."
"Diet and activity are inextricably linked," Moore said. "Healthy lifestyles include both."
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NEXT: Most find active ingredient in weight-control recipe hard to swallow
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