Here's the question as we posed it to our panel this month:
"A recent study into obesity done in Sweden has shown that exercise contributes very
little to achieving initial weight loss. While we all agree that exercise is beneficial
to our health, do you believe it's integral to successful weight loss?"
From Fred Pescatore, M.D.
The Centers For Integrative and Complementary Medicine
Author of The Hamptons Diet
While that may be true in Sweden, where people tend to be thinner and more active than sedentary
Americans, I tend to disagree on some level. The younger you are, the less likely that exercise
is mandatory for successful weight loss. It all come down to what one considers successful. If
losing a pound makes you successful but gaining three then makes you unsuccessful, then exercise
is not a necessary component to weight loss. But, most studies point out that those who exercise
more successfully manage their weight without the unhealthy yo-yo effects. Exercise has also
been shown to decrease cardiovascular events, so it may be worth getting off that couch and
living a little longer.
From Pete Maletto
CSO, DynaPure Nutrition
I?ve worked with professional athletes a good part of my life and I can speak from first hand experience
that exercise will instantly increase metabolism, decrease insulin resistance and mobilize fatty acids.
Timing of when you exercise is never an issue, but timing of when you eat and exercise always is, attributing
to its effectiveness.
Of course, we know that when living a low carbohydrate diet, glucose levels stay very low in muscle cells.
When we exercise at the proper heart rate (70%) our body can burn off the remaining glucose and switch over
to fatty acids. The lower the glucose level in the muscle cell, the faster we will get into a burning fat
mode during cardiovascular exercise. Many nutrients are helpful at making this fat loss process happen even
For example, lets say your a high carb kind of guy and ate Oatmeal for breakfast and then jumped on the
treadmill for a half hour. For over 20 minutes or so, you would be doing a great job at burning off the
Oatmeal and very little to burn body fat, utilizing glucose provided by the oatmeal. This is one way to
make any study on exercise fail.
But if you woke up when glucose levels are low, drank a glass of water and then went on the treadmill
you would burn the remaining glucose and immediately burn body fat within minutes of reaching heart rate.
If doing exercise first thing in the morning isn?t for you, then I would suggest working out with
weights for over a half hour, lowering glucose levels and then engaging in a cardiovascular exercise
for a half hour on the treadmill.
Exercise is always helpful no matter what, but exercise in correlation to the timing of our diet is
what makes the difference between a 1 or a 3 pound fat loss per week. Observe due measure, for the
right timing in all things is the most important factor for success.
From Gil Wilshire, M.D., FACOG
President and Chief Scientific Officer,
I am very skeptical of any study that looks only at "weight" (i.e. number on a scale). I am much
more interested in body composition and nutrient data. If someone has a very low body fat composition,
I really don't care how much their muscle and bones weigh. In fact, body builders would be categorized
as "obese" if we only looked at their height and weight. I am also skeptical of low calorie diets that
are deficient in vitamins, minerals, essential fatty acids, anti-oxidants, etc. It makes no sense to
lose weight, only to die of a degenerative or neoplastic disease down the line.
Despite the findings of one study with respect to one outcome: weight loss, I must still keep my
attention on the Big Picture. Exercise has so many benefits on so many of our inter-related systems,
that I remain a strong advocate for vigorous activity. It is my personal experience in my own weight
loss story that the exercise has tremendously bolstered my emotional state. This has allowed me to
persist with the ongoing discipline and positive attitude that has been essential to my continued
improvement in health. Demoralization is the common denominator for virtually all failures of weight
loss programs; exercise is a crucial component in maintaining the all-important mental attitude.
(It also doesn't hurt when people start complementing you on the improved appearance. These little
random perks are always good for a lift and a re-charge of determination!)
From Jonny Bowden, M.A., C.N., C.N.S.
Certified Nutrition Specialist
If you held a gun to my head and asked me what contributes more to weight loss - especially
initial weight loss - it would be a no-contest: diet wins. Even an hour a day on the treadmill
can't compete with a couple of supersized meals at the Fast Food Emporium.
However, that said,
the research is pretty clear that people do not keep weight off without exercising. So while
exercise may not contribute all that much to initial weight loss compared to diet, it is still
a critical component to maintaining weight loss, and those who exercise and change their eating
patterns do better with initial weight loss than those who don't. Plus exercise does two other
things that diet doesn't: one, it improves cardiovascular health and two (maybe even more
important) it builds muscle, which is your best ally in weight loss. Why?: Because calories -
including fat calories - are burned in the muscle cells. Without muscle, trying to "increase"
your metabolism and burn more calories is like trying to heat a 10 room farmhouse with only one
fireplace. The muscle cells are the fireplaces in your body - the more you have, the better
calorie burner you are and the more successful your weight loss efforts will be.
From Richard Feinman, Ph.D.
Professor of Biochemistry
State University of New York Downstate Medical Center
Many nutritional studies show exercise contributes very little to achieving initial weight loss.
Obviously, exercise is not required but here's a good study that shows its benefit:
Goodpaster, Katsiaras, and Kelley
Enhanced Fat Oxidation Through Physical Activity Is Associated With Improvements in
Insulin Sensitivity in Obesity
Diabetes 52:2191?2197, 2003
This study examined whether a combined intervention of physical activity and weight loss influences
fasting rates of fat oxidation and insulin-stimulated glucose disposal. Obese volunteers without
diabetes, completed 16 weeks of moderate-intensity physical activity combined with caloric reduction.
?Fat mass and regional fat depots were reduced and VO2max improved?.Rates of fat oxidation following
an overnight fast increased and the proportion of energy derived from fat increased from 38 to 52%.
In conclusion, exercise combined with weight loss enhances postabsorptive fat oxidation, which
appears to be a key aspect of the improvement in insulin sensitivity in obesity.