For all the time and effort Americans put into dieting, we have a lot of misconceptions about weight loss. Read on to find out which six beliefs about shedding pounds it's time to lose.
Cut or Burn 3,500 Calories to Lose a Pound
The 3,500-calories-equals-a-pound rule is known to nearly every dieter on the planet. What most don't know is that this bit of arithmetic comes from a small starvation study done in the 1950s.
Diana Thomas, a mathematician who is director of the Center for Quantitative Obesity Research at Montclair State University in New Jersey, said the formula grossly underestimates real-world weight-loss efforts and often leaves dieters sorely disappointed by their lack of results.
"Clicking off 3,500 calories to lose a pound may be close enough to the truth for the first 10 to 12 days of a diet as you lose water weight, but when the body weight drops you carry less mass and start to burn fewer calories for the same activities," she said. "After a period of time, you stop losing weight even if you continue to cut back by the same amount."
Thomas said new prediction models were developed in the 1970s that took into account everything from age, height, sex and body fat, but they required so much complicated math they never really caught on. Thankfully, this Internet calculator does the math for you.
You Gained It So You Can Lose It
Nikhil Dhurandhar, an obesity researcher at the Pennington Biomedical Research Center in Baton Rouge, La., confirms that it is, of course, possible to lose weight -- but gaining weight takes much less effort.
You can consume hundreds or even thousands of calories more than you require without too much effort, Dhurandhar said, and every time you do, excess calories are stored as body fat.
However, losing weight requires a sustained daily effort and you can only cut back or burn off so much beyond your baseline requirements. Meaningful weight loss usually happens slowly over a long period of time with lots of plateaus along the way, something most of us don't have the patience for.
"If it was easy, you'd see more people pulling it off," he said.
Heroic efforts don't always pay off, either. As virtually every weight loss trial has shown, weight loss tends to grind to a halt at around the six-month mark.
"It could be because of changes in resting metabolism or people begin to slip a little, we really don't know," he said. "But we do know that the body likes to hold on to weight."
Exercise Won't Help You Lose Weight
Do coach potatoes have an easier time shedding weight than gym rats? That's what a spate of recent studies appeared to suggest when they found exercisers tended to compensate for any extra physical activity by eating more.
However, James Hill, the executive director of the Anschutz Health and Wellness Center at the University of Colorado, said such studies are misleading.
"In the first place, many studies don't use a high enough dose of exercise to promote weight loss," he said. "And secondly, exercisers do tend to compensate by eating more, but not enough to make up for all of the calories they burn up in exercise. They still create a negative energy balance and they still have an easier time losing weight and keeping it off than people who don't exercise."
Hill was adamant that it is virtually impossible to keep weight off for any period of time without working up a sweat on a regular basis. He said that lack of exercise promotes metabolic defects that make it harder to lose weight and are generally bad for your health.
The National Weight Control Registry, run by Hill, tracks the health habits of thousands of people who have lost an average of 60 pounds and kept it off for at least two years. More than 90 percent of registrants say they exercised for an hour or more a day.
Removing One Food From Your Diet Is the Secret to Weight Loss Success
Hill also cautioned against the idea that removing a specific food from the diet will magically make the weight melt off your body. Even though most diet books are based on this premise, it simply isn't true.
"You might lose weight initially by limiting a certain food, but it's because you eat fewer calories," he said. "Most people can't sustain it in the long term, so the approach is doomed to failure."
Even soda, often maligned for its contribution to the obesity epidemic, is a good example. Hill said that he supports limiting sugar-sweetened drinks and believes overconsumption is bad for health, but he said the data is mixed on whether removing soda from the American diet would shrink our collective waistlines.
"It might have a tiny effect, but there's nothing stopping people from replacing it with something else," he said. "If you eat more than one thing, it will probably take changing more than one thing to lose weight."
Everyone Gains (and Loses) the Same Way
In 1990, Canadian researcher Claude Bouchard wanted to test the idea that everyone gains weight in exactly the same way, so he asked 12 sets of male identical twins to overeat by 1,000 calories a day while limiting their physical activity to just 30 minutes. To ensure they stuck with the program, he locked them in a room and carefully controlled every morsel they ate for 90 days.
Bouchard predicted that by the end of their stay, each of his volunteers would gain 24 pounds. But that's not what happened.
Some sets of twins gained as little as 10 pounds while other sets added nearly 30 pounds. The twins in each set gained virtually the same amount of weight, but the difference in weight gain between unrelated sets of twins was threefold and their pattern of fat distribution differed by sixfold.
When the researcher turned the tables in a later study and asked sets of twins set to burn off more calories than they took in, the pounds melted off some but clung stubbornly to others. Numerous other studies have produced similar results, highlighting the fact that some people are predisposed to gain weight easily and must work harder than the average person to burn it off.
Eating Six Small Meals Is Best for Weight Loss
There's little evidence to support the idea that eating smaller, more-frequent meals will improve weight loss results.
For example, a recent British Journal of Nutrition investigation found no weight-loss difference between dieters who ate their calories in three meals versus six daily meals. And, in fact, another study in the same journal concluded that eating two large meals a day can be the ideal weight loss strategy for some.
"Eating six meals a day can work for someone who has a lot of discipline," Dhurandhar said. "But for others, it's like offering an alcoholic a glass of wine six times a day. Their willpower just can't take it."
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