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Can low carb dieters eat all they want, and still lose weight?
"The Atkins Nutritional Approach counts grams of carbohydrates
instead of calories... If you are losing weight, there is no
need to concern yourself with counting calories. " Source:
atkins.com
You might be doubtful and chances are that mainstream diets are
the reason. Of course you couldn't avoid opinions like the below
Q&A posted by Health Care Reality Check: Q: Can a person eat
unlimited calories, and still lose weight, as long as they
severely restrict carbohydrates? A: No, she can not. The basis
of ketogenic diets, such as the Atkins Diet, is a severe
restriction of carbohydrate calories, which simply causes a net
reduction in total calories. Since carbohydrate calories are
limited, intake of fat usually increases. This high fat diet
causes ketosis (increased blood ketones from fat breakdown),
which suppresses hunger, and thus contributes to caloric
restriction. -- Ellen Coleman, RD, MA, MPH Is this a correct
answer? Let's first discuss whether it's a correct question. Or,
rather, is this the real question so frequently asked by
dieters. In my experience, this in fact sounds a little bit
different but this makes ALL the difference. This is what real
dieters ask: Q: Can low carb dieters eat all they want, and
still lose weight as long as they only eat allowed foods? A:
Yes, they can. The basis of ketogenic diets, such as the Atkins
Diet, is a restriction of carbohydrate-containing foods in favor
of fat and protein containing foods, which causes the state of
ketosis resulting in significant decrease in appetite. Since
appetite decreases, most of low carb dieters consume
significantly less calories WITHOUT INTENTIONAL CALORIE
RESTRICTION. Is there scientific evidence? There is. Study #1
by: Bassett Research Institute in Cooperstown, NY and Durham
(N.C.) Veterans Affairs Medical Center. Reported: Proceedings of
North American Association for the Study of Obesity, Oct. 29,
2000, Long Beach, Calif. Who participated: 18 obese men and
women with 30 or more pounds to lose. Average calorie intake
before the study: 2,481 calories a day Method: Dr. Atkins' Book,
the "New Diet Revolution" used as instruction for the dieters.
Results: 1. Calorie intake during the most restrictive induction
phase (when only 20 g of carbohydrates were allowed) was 1,419
calories a day on average and weight loss was more than 8 pounds
on average. 2. Calorie intake during the ongoing weight-loss
phase (when carbohydrate intake is being increased gradually, by
5 g a day) dieters ate an average of 1,500 calories a day and
lost an additional 3 pounds in two weeks. 3. The calorie
reduction was attributed almost completely to carbohydrate
abstaining. Intake of fat and protein remained practically the
same as before the diet. 4. After 6 months on Atkins diet, 41
overweight people lost an average of 10% of their weight. Most
dieters lowered their cholesterol by 5%, but there were a few
whose cholesterol increased. 5. 20 out of 41 dieters continued
the program, and kept the lost weight off for more than a year.
Study #2 by: Harvard School of Public Health. Reported: American
Association for the Study of Obesity, October 16, 2003 Who
participated: 21 overweight volunteers. Two groups were randomly
assigned to either lowfat or low-carb diets with 1,500 calories
for women and 1,800 for men; a third group was also low-carb but
got an extra 300 calories a day. Method: All the food was
prepared at a restaurant in Cambridge, Massachusetts. Note that
most earlier studies including the above Study #1 simply gave
out diet plans. So in this study, dieters were given dinner and
a bedtime snack as well as breakfast and lunch for the next day,
which made the setting a carefully controlled one. Foods were
mostly fish, chicken, salads, vegetables and unsaturated oils.
Red meats and saturated fats were limited (as opposed to
traditional Atkins menus.) All meals looked similar but were
cooked to different recipes. The low-carb meals were 5% carbs,
15% protein, 65% fat. The low fat group got 55% carbohydrate,
15% protein, 30% fat. Results: 1. All dieters lost weight, but
those on low carb diet lost more than the low fat group -- even
while consuming MORE calories: - Group on lower-cal, low-carb
diet lost an average of 23 lbs. - Group on same-calories low-fat
diet lost an average of 17 lbs. - Group on extra 300 calories,
low-carb diet lost an average of 20 lbs. 2. Over the course of
the study, the group of low carb dieters who got an extra 300
calories a day consumed extra 25,000 calories. That should have
added up to about seven pounds. But for some reason, it did not.
Discussion: "It doesn't make sense, does it?" said Barbara Rolls
of Pennsylvania State University. "It violates the laws of
thermodynamics. No one has ever found any miraculous metabolic
effects." So it violates the laws of thermodynamics, huh? Not so
fast! When it comes to calorie counting, the "calorie is a
calorie" concept is very deceiving. Let's see what we count when
we think we count calories. When you burn a piece of wood in a
stove, you can directly measure how much heat energy it
produces. Then you can claim that you know how many calories a
piece of wood contains, right? Not exactly. You should specify
what kind of wood it was, dry or wet, how you burned it, etc.
Because if you spent another material to start the burning, you
should subtract these calories from the total; if the wood was
wet you should take into account the calories that the water
evaporation took. So even with a piece of wood, it's not that
simple. Now look at a piece of food. You know how they tell how
many calories it contains? Same way they talk about a piece of
wood in a stove. It's the calorie number that the food would
produce by being burnt in a stove. Then in addition to the
wood's calorie estimation (that takes into account the dryness,
etc.), you should add many more circumstances: how hard should
one chew it before being able to swallow, how hard one's enzyme
system will have work to digest it, will it influence the
hormones in charge of fat storing? What about its effect on the
hormones in charge of fat burning? Which chain of reactions will
it trigger, activity-wise or metabolism-wise? Will it make one
sleepy, thus conserving the energy? Ot will it make one jumpy,
thus wasting the energy? Study #3 by: Laboratory of Applied
Physiology, Graduate School of Human and Environmental Studies,
Kyoto University, Kyoto 606-8501, Japan Reported: J Clin
Endocrinol Metab. 2003 Dec;88(12):5661-7 Method: Healthy boys,
aged 8-11 yr, were examined for resting energy expenditure and
the thermic effect of a meal, which were measured for three
hours after a same-calorie but high-fat or a high-carb meals.
Results: There was no changes after high carbohydrate meals but
there was an increase in resting energy expenditure after a
high-fat meal. If the researchers in the Study #2 would have
measured resting energy expenditure and the thermic effects of
the meals, they would probably have registered the same changes.
Then everybody would make a sigh of relief: none of the laws of
thermodynamics have been violated: yes, the low-carb dieters
COULD INDEED eat more calories and lose more weight than the
low-fat group while violating no physical laws because -- they
just burnt more, all the time, even at rest. It's that simple.
About the author:
Tanya Zilberter, PhD, is a researcher, health educator, exercise
physiologist, and scientific journalist.
In health sciences since 1972, Dr. Zilberter authored several
hundred scientific and popular publications, including four
print books and more than a dozen of eBooks.
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