Five Things You’re Getting Wrong About Weight and Weight Loss

If I’m thin then I’m healthy, right? Wrong. There are several misconceptions people have about weight, losing it and what’s healthy. Here’s the low-down on some myths we’re better off busting.

Kids have to lose weight to shed obesity: As children grow, they put on weight, but how much is normal, and how much is excessive and potentially a hazard to their health? In the latest study, published in the journal Lancet, researchers from the National Institute of Diabetes and Digestive and Kidney Diseases at the National Institutes of Health developed a mathematical model to differentiate between healthy weight gain and the extra pounds that contribute to obesity.

The model takes advantage of more accurate assessments of how many calories heavier children take in, as well as how quickly and efficiently they burn off those calories, and the ratio of fat to muscle in their bodies. The resulting model shows some kids can outgrow their obesity around puberty even if they don’t lose weight. That’s because obesity is a measure of not just weight but the ratio of height to weight known as the body mass index (BMI), and as children grow, they transform fat into muscle, which can weigh as much, if not more than fat tissue. So kids with a high BMI that might suggest obesity may not actually be overweight.

Still, the researchers say that teaching children about portion control and balancing what they eat with physical activity to burn off excess calories are important lessons to learn early.



You can’t be fat and still be fit: A person’s level of physical fitness, as well as his weight, matters for overall health. A study in 2012 showed that overweight and obese people were at no greater risk of developing or dying from heart disease or cancer compared to normal weight people, but only if they were as metabolically fit as their slimmer counterparts. When it comes to premature death, it’s less about how much fat a person carries, but what kind of fat. Visceral or belly fat, for example, is considered more metabolically harmful than fat that sits just under the surface of the skin. Visceral fat, which is embedded more deeply within muscles and organs like the liver, release agents that can disturb the body’s energy balance, shunting calories into fat. Lean people can have high levels of visceral fat in their tissues, while overweight individuals may be carrying more subcutaneous fat and therefore could even be metabolically fitter than those who are slimmer.

Most people who put on weight, however, don’t enjoy a fit status for long. Eventually, the excess weight can contribute to higher rates of high blood pressure, diabetes, and heart disease.

You can eat what you want and just exercise to lose weight: Cutting calories by adjusting what you eat is actually the most effective way to lose weight. Ideally, consuming fewer calories and exercising is a more efficient way of dropping pounds, but for most people, passing up the chips is easier than sweating it out on a treadmill for an hour. Downing 140 calories from a can of soda, for example, takes only a few minutes, but would take half an hour of moderately intense walking to burn off. “You can greatly undermine weight loss efforts and general health by not considering the quality of the foods you eat. It is important to consider calorie density and nutrient density of foods to maximize exercise performance and improve health status,” says Gayl Canfield, the director of nutrition at Pritikin Longevity Center.




Long bouts of low-intensity exercise are best for losing weight: Fitness experts are trying to de-bunk the myth that pounds melt off faster with low-intensity aerobic exercise than higher intensity workouts. “It’s true the body burns proportionally more fat calories than carbohydrate calories at a lower training intensity, however, should you increase your exercise intensity into the cardiovascular zone you will burn more overall calories,” says Scott Danberg, the director of fitness at Pritikin Longevity Center. Mixing in some short bouts of high-intensity exercise can translate into benefits on the scale.

Eating protein is the best way to feel full and keep calories in check: Lean protein is indeed a good way to get filled up, but fiber is even better, because it comes with fewer calories. To make sure you’re not feeling hungry but still getting all your nutrients, load your plate with fruit, vegetables beans and grains.

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Myths Surround Breakfast and Weight

 Americans have long been told that routinely eating breakfast is a simple habit that helps prevent weight gain. Skipping breakfast, the thinking goes, increases hunger throughout the day, making people overeat and seek out snacks to compensate for missing that first – and some would say most important – meal of the day. “Eating a healthy breakfast is a good way to start the day,” according to the Web site of the United States surgeon general, “and may be important in achieving and maintaining a healthy weight.”

 


But new research shows that despite the conventional weight-loss wisdom, the idea that eating breakfast helps you lose weight stems largely from misconstrued studies.

Only a handful of rigorous, carefully controlled trials have tested the claim, the new report, published in The American Journal of Clinical Nutrition, found. And generally they conclude that missing breakfast has either little or no effect on weight gain, or that people who eat breakfast end up consuming more daily calories than those who skip it.

But those trials have been largely overlooked, and their findings drowned out by dozens of large observational studies that have found associations between breakfast habits and obesity but no direct cause and effect, said Dr. David B. Allison, director of the Nutrition Obesity Research Center at the University of Alabama at Birmingham. Dr. Allison and his colleagues scoured the medical literature and found that the only long-term, carefully controlled trial that randomly assigned people to routinely eat or go without breakfast and then measured the effect on their body weight was published in 1992.

That seminal study, carried out over 12 weeks at Vanderbilt University, had mixed results. Moderately obese adults who were habitual breakfast skippers lost an average of roughly 17 pounds when they were put on a program that included eating breakfast every day. And regular breakfast eaters who were instructed to avoid eating breakfast daily lost an average of nearly 20 pounds.

Both programs included an identical amount of calories, and each caused people to lose more weight than a program in which a person’s typical breakfast habits did not change.

The study was fairly small and limited, involving only 52 overweight adult women, but it suggested that as far as breakfast is concerned, the most important factor in weight loss may be how drastically you change your routine. “Those who had to make the most substantial changes in eating habits to comply with the program achieved better results,” the authors wrote in their paper.

Dr. Allison said that the findings “showed no effect over all of eating versus skipping breakfast, that people do equally well on either one.”

“You would think at this point that you would either abandon the idea or do some more randomized controlled trials,” he added. “But instead the association studies started.”

Through the years, the equivocal findings were wildly misinterpreted. Dr. Allison and his colleagues found about 50 subsequent articles on breakfast and body weight in the medical literature that cited the Vanderbilit research. Of those papers, 62 percent cited the findings inaccurately, and they were almost exclusively biased in favor of the idea that eating breakfast protects against weight gain.

Another study that became the basis of widespread misinformation was published in 2002. In that study, researchers looked at data from the National Weight Control Registry, which tracks thousands of people who have lost weight and kept it off for at least a year.

Data from the registry showed that after their weight loss, about 80 percent of people reported regularly eating breakfast. “There was no difference in reported energy intake between breakfast eaters and non-eaters,” the registry showed, “but breakfast eaters reported slightly more physical activity than non-breakfast eaters.”

The research showed only that eating breakfast was a common behavior among people who were actively trying to avoid regaining weight, just as diet soda might be a common drink of choice among dieters but not necessarily the cause of their weight loss.

But of 72 subsequent research articles on breakfast and weight loss that cited the registry study, about half overstated its findings, Dr. Allison found, and roughly a quarter suggested that it showed a causal relationship between breakfast habits and obesity.

In the real world, when people form an opinion, they tend to seek out evidence that supports it and discard anything that contradicts it, a phenomenon academics refer to as confirmation bias.

“Scientists are humans, and they’re susceptible to confirmation bias too,” Dr. Allison said.

In the meantime, a small number of randomized trials has continued to cast doubt on the protective effect of breakfast. At Cornell University, for example, scientists have showed in experiments that in some cases, but not all, depriving people of breakfast can lead them to eat more calories at lunch. But those extra calories do not make up for the calories they missed at breakfast, so at the end of the day, they still end up eating fewer calories over all.

The Cornell researchers have argued that for some adults, skipping breakfast may actually be a good way to reduce weight – not gain it.

Dr. Allison said that the true relationship between eating breakfast and body weight, if there is one, was still an open question. But observational studies that tout an association between the two are churned out “just about every week,” despite doing nothing to actually test or prove the claim.

“At some point, this becomes absurd,” he said. “We’re doing studies that have little or no value. We’re wasting time, intellect and resources, and we’re convincing people of things without actually generating evidence.”

As for why the subject has created something of an echo chamber of observational research, Dr. Allison said that unlike randomized controlled trials, which are expensive and difficult to carry out, sifting through large sets of observational data to find tantalizing associations is fairly low cost and easy to do.

“Just like bakers bake bread, scientists write papers,” he said, “and we get rewarded for writing and publishing papers.”

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