Recent studies discussed in the New York Times

at 12:29 PM

New York Times, March 2, 2010- In Obesity Epidemic, What's One Cookie?

We all know the basic formula for gaining and losing weight; a pound of fat equals 3,500 calories. This has fueled the widely accepted idea that weight loss only requires small changes that add up. As a result, cutting out or burning just 100 calories a day can lead to significant weight loss over time: a pound every 35 days and more than 10 pounds a year.

However... it's also misleading. Numerous scientific studies show that small changes have almost no long-term effect on weight. When you skip a cookie or exercise a little more, the body's biological mechanisms kick in (homeostasis) and reduce the caloric benefits of our well-intentioned efforts. A recent commentary that was published in the Journal of the American Medical Association (JAMA) noted that the 'small changes' theory fail to take the body's adaptive mechanisms into account.

"This does not mean that small improvements are futile, but people need to take a realistic view of what they can accomplish".

Dr. David Ludwig at Children's Hospital Boston and the co-author of the JAMA commentary says, "As clinicians, we celebrate small changes because they often lead to big changes. An obese adolescent who cuts back TV from six to five hours each day may then go on to decrease viewing much more. However, it would be entirely unrealistic to think hat these changes alone would produce substantial weight loss".

So here is how it works, if there is an imbalance between the calories consumed and the calories burned (a significant imbalance), weight gain or weight loss will result. BUT... bodies don't gain or lose weight indefinitely. Eventually, a cascade of biological changes and adaptations kick in to help the body maintain a new weight. As the JAMA article continues, a person who eats an extra cookie a day will gain weight; some! But overtime, some of the extra calories also go to taking care of the extra body weight. Similar idea when we lose a little weight, we need fewer calories to maintain the new lower body weight.

And a lot of people will skip the cookie but unknowingly compensate by eating a bagel later or an extra serving of pasta at dinner.

Leptin is a hormone made by the body's fat cells that regulates food intake and energy expenditure. Dr. Jeffrey Friedman is the head of Rockefeller University's molecular genetics lab, which first identified leptin. "If you ask anyone on the street, why is some one obese? They'll say, they eat too much". He says that while that is true, a deeper question is why do they eat too much? He continues to say that there are many important drivers to eat and it is not a purely a conscious or higher cognitive decision.

However Dr. James Hill, director of the center for Human Nutrition at the University of Colorado Denver, says that while long term weight loss requires significant life style changes, taking away extra calories can help prevent weight gain. "Once you're trying for weight loss, you're out of the small-change realm". Dr. Hill Says.

But small changes in diet and exercise can help prevent heart problems and diabetes. We need to know what we are up against in terms of biological challenges and then design a plan that will address those challenges.












.