Make the Lifestyle Change and Feel Better About
Obesity Epidemic, What’s One Cookie?
basic formula for gaining and losing weight is well known: a pound of
fat equals 3,500 calories.
That simple equation has fueled the widely accepted notion that weight
loss does not require daunting lifestyle changes but “small changes that
add up,” as the first lady, Michelle Obama, put it last month in
announcing a national plan to counter childhood obesity.
In this view, cutting out or burning just 100 extra calories a day — by
replacing soda with water, say, or walking to school — can lead to
significant weight loss over time: a pound every 35 days, or more than
10 pounds a year.
While it’s certainly a hopeful message, it’s also misleading. Numerous
scientific studies show that small caloric changes have almost no
long-term effect on weight. When we skip a cookie or exercise a little
more, the body’s biological and behavioral adaptations kick in,
significantly reducing the caloric benefits of our effort.
But can small changes in diet and exercise at least keep children from
gaining weight? While some obesity experts think so, mathematical models
The first lady, Michelle Obama, spoke last month at the White House
about her “Let’s Move” initiative, which aims to change the way children
eat and play.
As a recent commentary in The Journal of the American Medical
Association noted, the “small changes” theory fails to take the body’s
adaptive mechanisms into account. The rise in children’s obesity over
the past few decades can’t be explained by an extra 100-calorie soda
each day, or fewer physical education classes. Skipping a cookie or
walking to school would barely make a dent in a calorie imbalance that
goes “far beyond the ability of most individuals to address on a
personal level,” the authors wrote — on the order of walking 5 to 10
miles a day for 10 years.
This doesn’t mean small improvements are futile — far from it. But
people need to take a realistic view of what they can accomplish.
“As clinicians, we celebrate small changes because they often lead to
big changes,” said Dr. David Ludwig, director of the Optimal Weight for
Life program at Children’s Hospital Boston and a co-author of the JAMA
commentary. “An obese adolescent who cuts back TV viewing from six to
five hours each day may then go on to decrease viewing much more.
However, it would be entirely unrealistic to think that these changes
alone would produce substantial weight loss.”
Why wouldn’t they? The answer lies in biology. A person’s weight remains
stable as long as the number of calories consumed doesn’t exceed the
amount of calories the body spends, both on exercise and to maintain
basic body functions. As the balance between calories going in and
calories going out changes, we gain or lose weight.
But bodies don’t gain or lose weight indefinitely. Eventually, a cascade
of biological changes kicks in to help the body maintain a new weight.
As the JAMA article explains, a person who eats an extra cookie a day
will gain some weight, but over time, an increasing proportion of the
cookie’s calories also goes to taking care of the extra body weight.
Eventually, the body adjusts and stops gaining weight, even if the
person continues to eat the cookie.
Similar factors come into play when we skip the extra cookie. We may
lose a little weight at first, but soon the body adjusts to the new
weight and requires fewer calories.
Regrettably, however, the body is more resistant to weight loss than
weight gain. Hormones and brain chemicals that regulate your unconscious
drive to eat and how your body responds to exercise can make it even
more difficult to lose the weight. You may skip the cookie but
unknowingly compensate by eating a bagel later on or an extra serving of
pasta at dinner.
“There is a much bigger picture than parsing out the cookie a day or the
Coke a day,” said Dr. Jeffrey M. Friedman, head of Rockefeller
University’s molecular genetics lab, which first identified leptin, a
hormonal signal made by the body’s fat cells that regulates food intake
and energy expenditure. “If you ask anyone on the street, ‘Why is
someone obese?,’ they’ll say, ‘They eat too much.’ ”
“That is undoubtedly true,” he continued, “but the deeper question is
why do they eat too much? It’s clear now that there are many important
drivers to eat and that it is not purely a conscious or higher cognitive
This is not to say that the push for small daily changes in eating and
exercise is misguided. James O. Hill, director of the Center for Human
Nutrition at the University of Colorado Denver, says that while weight
loss requires significant lifestyle changes, taking away extra calories
through small steps can help slow and prevent weight gain.
In a study of 200 families, half were asked to replace 100 calories of
sugar with a noncaloric sweetener and walk an extra 2,000 steps a day.
The other families were asked to use pedometers to record their exercise
but were not asked to make diet changes.
During the six-month study, both groups of children showed small but
statistically significant drops in body mass index; the group that also
cut 100 calories had more children who maintained or reduced body mass
and fewer children who gained excess weight.
The study, published in 2007 in Pediatrics, didn’t look at long-term
benefits. But Dr. Hill says it suggests that small changes can keep
overweight kids from gaining even more excess weight.
“Once you’re trying for weight loss, you’re out of the small-change
realm,” he said. “But the small-steps approach can stop weight gain.”
While small steps are unlikely to solve the nation’s obesity crisis,
doctors say losing a little weight, eating more heart-healthy foods and
increasing exercise can make a meaningful difference in overall health
and risks for heart disease and diabetes.
“I’m not saying throw up your hands and forget about it,” Dr. Friedman
said. “Instead of focusing on weight or appearance, focus on people’s
health. There are things people can do to improve their health
significantly that don’t require normalizing your weight.”
Dr. Ludwig still encourages individuals to make small changes, like
watching less television or eating a few extra vegetables, because those
shifts can be a prelude to even bigger lifestyle changes that may
ultimately lead to weight loss. But he and others say that reversing
obesity will require larger shifts — like regulating food advertising to
children and eliminating government subsidies that make junk food cheap
“We need to know what we’re up against in terms of the basic biological
challenges, and then design a campaign that will truly address the
problem in its full magnitude,” Dr. Ludwig said. “If we just expect that
inner-city child to exercise self-control and walk a little bit more,
then I think we’re in for a big disappointment.”