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.