In a debate just published online in the International Journal of Obesity, obesity and nutrition expert, Dr. David Katz — Director of the Yale-Griffin Prevention Research Center — says it is forks over feet.
Calories in, rather than calories out, says Katz, are the main cause – and the main hope for a cure – for epidemic childhood obesity.
“I would not want to choose between physical activity and diet for overall health,” Katz notes. “As I indicate in the piece requested by the International Journal of Obesity, exercise is the vital conditioning work of the human machine, and food is its fuel. Both are vital to health.”
However, Katz states that his “mission” for the journal was to take one side in a debate. Which is more important as a cause, and potential solution, to the problem of epidemic childhood obesity: excess eating, or inadequate physical activity?
“There is no question that both are relevant as we look at causes,” Katz says. “But there really is no comparison when it comes to the magnitude of influence. Just think of the readily accessible range of physical exertion, and compare that to that to the readily accessible range of calories.”
In the article, Katz uses specific examples to show how much physical activity is required to burn specific numbers of calories, and how little eating or drinking can replace them. For instance, a 155-pound man who played basketball for an hour or walked moderately fast for 2 hours would expend about 550 calories from either activity. But if he stopped at a fast food restaurant afterward for a large soda and small order of fries, he would immediately undo all the hard work that went into burning those calories. Although it is somewhat more difficult to come up with a reliable estimate of how many calories children expend through exercise, the basic concept of ‘calories in’ versus ‘calories out’ still applies.
Katz reaches the basic conclusion that childhood obesity will never be controlled without addressing the ‘calories in’ side of the energy balance equation. He states in the article that the average person — child or adult — “can readily out-eat almost any realistic level of exercise, but will find it virtually impossible to out-exercise an unrestrained level of calorie intake. Although both sides of the energy balance equation matter, if forced to pick sides, we should prioritize ‘forks’ over ‘feet’ for weight control, based on both science and sense.”
To Access the Full Article Online:
PDF version: http://www.nature.com/ijo/journal/vaop/ncurrent/pdf/ijo2010218a.pdf
HTML version: http://www.nature.com/doifinder/10.1038/ijo.2010.21
About Dr. David Katz
David L. Katz MD, MPH, FACPM, FACP directs the Yale-Griffin Prevention Research Center, which he co-founded in 1998. As director of this research center dedicated to chronic disease prevention, Katz has served as Principal Investigator for numerous community and clinical trials, and has acquired and managed over $20 million in research funds. He is internationally recognized as an authority on chronic disease prevention, weight control, and nutrition.
About Yale-Griffin Prevention Research Center
The Yale-Griffin Prevention Research Center (PRC) was established in 1998 through funding from the Centers for Disease Control (CDC). One of 37 such centers nationwide representing academic/community partnerships, the Yale-Griffin PRC is engaged in interdisciplinary applied prevention research in collaboration with community partners, federal, state, and local health and education agencies, and other universities. The goal the PRC is to develop innovative approaches to health promotion and disease prevention that will directly benefit the public’s health, first locally, and then nationally. For more information, visit www.yalegriffinprc.org
