Mind over metabolism and your mass

Spending hours at the gym and having a strict diet can be frustrating when you do all the work and see no results. But researchers say this is a common struggle that will eventually occur when trying to shed those extra pounds.

Traditionally, people have been told the general rule to lose one pound is to reduce their caloric intake by 3500 calories a week. This is because one pound of fat is equivalent to 3500 calories. It assumes that if a person keeps up this caloric reduction, it would result in a slow and steady weight loss over time.

In reality, it will take twice as long to lose those pounds.

“People have used this sort of rule of thumb to predict how much people should lose for decades now, and it turns out to be completely wrong,” says Dr. Kevin Hall, a scientist at the U.S. National Institute of Health.

The rule fails to account for the bodily change that occurs once a person slims down. The metabolism, which is the rate at which a body burns calories, alters once there is a change in diet or exercise routine.

Exercise and healthy eating are an important part of weight loss. Photo courtesy of Sasha W. on flickr.

Alfonso Abizaid, an obesity researcher and associate professor of neuroscience at Carleton University in Ottawa, says metabolism will slow down once weight loss begins. This is because the body will not be working as hard to burn those extra calories, he says.

If the current 3500 calorie rule were true, it would have to work in the opposite direction as well, Abizaid says.

“If I ate one potato chip a day, it would mean I would gain a pound every month,” he explains. “Because there are so many calories in one fried potato chip.”

Researchers at the U.S. National Institute of Health have devised a new guideline to account for the change in metabolism once a person decides to lose weight.

Based on mathematical calculations, the guideline supports the idea that if a person wants to lose ten pounds, they would have to cut 100 calories per day. Five of those pounds would be gone in one year.

Eventually, the goal weight will be reached in three years.

“We fully recognize that people aren’t going to be necessarily willing to wait three years to reach their goal weight,” says Hall. But the new rule would allow people to think realistically about their weight loss goals.

Overcoming the plateau

During the weight-loss process, a common and often frustrating phenomenon that occurs is a weight-loss plateau. This means the body has adjusted to the metabolic changes in the body and therefore will not shed any more pounds, says Hall.

Abizaid says the hypothalamus is partly to blame for this plateau. The hypothalamus is a part of the brain responsible for determining the metabolic rates for an individual. It creates a ‘set point’ for a person’s metabolic rate, he says.

When a person begins to change their diet or fitness routine, the metabolism will change and the hypothalamus will send signals to the body telling it to return to that original metabolic ‘set point,’ he says.

“Essentially your body will start defending whatever body fats are there and you can be very skinny at this point or you could still be overweight,” he explains. “But your body will fight losing weight.”

Abizaid says this new rule is very general and does not take into account the different body types of an individual.

“These are guidelines and we have to understand that,” says Abizaid. “And there is some truth to them, but you have to make big assumptions with this.”

Those attempting to lose weight are often discouraged when they reach their plateau. Courtesy of 05com on flickr.

In an effort to cater the new guidelines to an individual, researchers created a computer-based simulator. Users simply have to plug in numbers, such as sex, age and weight. They then add their weight loss goal. The simulator — which has now approached half a million users — will inform a person how long it will take to reach a goal based on the research.

“People have very great expectations about the amount of weight they can lose in a period of time,” says Hall. The simulator is designed for an individual to set realistic goals, he says.

Obesity as an epidemic

The rise of obesity is not new. The World Health Organization described the trend as a global epidemic in 1997. Today, one in four Canadian adults are obese, according to the Public Health Agency of Canada.

Commercial weight loss programs are designed to encourage people to lose weight. The programs usually call for a change in both diet and exercise routine. However, most of the programs do not account for the weight-loss plateau.

One of the greatest challenges for those trying to lose weight is not just losing it, but keeping it off, says Abizaid. This new general guideline would allow people to become aware of the plateau that occurs.

“A lot of these weight loss programs are effective in the first two or three months,” says Abizaid. “You have to continue the diets and the exercise for long periods of time in order to not lose any more, but just maintain that weight.”

A recent article published in the Journal of the American Dietetic Association calls for nutritionists and dieticians to communicate to their clients the realistic approach to slimming down.

This includes speaking with a client to set a realistic weight loss goal, as well as informing them that being healthy is more than about the numbers on a scale.

It recommends that clients should be aware that a weight-loss plateau will occur and this is a normal and expected part of the weight loss process.

“It is a lifestyle change,” says Abizaid. “It’s not just dieting. It has to do with exercise and healthy eating.”

“And that will help with a more sustained body weight,” he says.

Produced by Matthew Irving

Front Page Photo courtesy of o5com on flickr.