Uncovering the Atkins diet secret

Eggs are a part of the Atkins diet

The controversial and popular Atkins diet works for reasons that Dr Atkins may not have fully understood, the BBC Two programme Horizon has discovered.

Through a series of scientific experiments the programme shows that although the diet allows people a healty quota of fat and protein, they actually eat as few calories as people on low fat diets.

And the reason for this, according to recent research is because the quantity of protein the regime encourages, acts like an appetite suppressant.

The meat, fish and eggs in the Atkins diet control hunger and stop people eating their usual quantity of calories.

The theory behind Dr Atkins' diet is that by cutting down on starchy foods like potatoes, bread and pasta and eating mainly protein and fats like meat, eggs and cheese you can eat as much as you want and still lose weight.

Dr Atkins even said there was no need to worry about calories.

Heresy

The idea that people do not have to worry about calories and still lose the pounds brought Dr Atkins much criticism and even prompted some scientists to call his diet "scientific heresy".

Fish is also allowed

Horizon teamed up with the University of Kansas and commissioned a scientific investigation to test Dr Atkins' most controversial theory.

This states that on his diet you actually burn more calories than usual - allowing you to lose more weight.

Dr Atkins had two ideas about where the extra calories were going. Firstly, he believed you burn more calories when your body uses fats and proteins as fuel.

If this is true, says Dr Mary Vernon, of the Atkins Physician Council, it makes exercise less important than usual.

"You wouldn't have to increase your exercise at all because your body would be working harder, so that you could literally sit in your armchair and lose weight."

Dr Atkins also believed that on his diet you lose unused calories by peeing them away, as part of a process known as ketosis, which happens when you stop eating starchy foods and sugar.

Twins' study

In Horizon's investigation identical twins were put on different diets, one on the Atkins diet and one on a conventional low fat diet. Each was fed identical amounts of calories for two weeks.

Potatoes are banned

The twins were then locked inside a sealed chamber so that Professor Joseph Donnelly could calculate how quickly their bodies were burning calories.

Over 24 hours the twin on the Atkins diet did lose more calories than the twin on low fat, but only 22.

Professor Donnelly even checked the twins' urine for calories and found that the Atkins dieter had lost less than a single calorie more than his brother on low fat.

Donnelly concluded that: "the differences were too small to suggest there's anything significant going on".

Even though this research is at an early stage, there is little evidence for Dr Atkins' wasted calorie theories.

Real reason

Horizon examines other studies that reveal the real reason scientists believe the Atkins diet is effective.

New results from research conducted on the popular BBC series 'Diet Trials' offer the first clue.

The study examined the Atkins diet and three low fat, low calorie diets.

All four diets worked, but Dr Joe Millward at the University of Surrey who headed up the research, discovered the secret to why Atkins dieters were losing weight.

"The Atkins dieters were eating less calories, in exactly the same way as those going to the slimming clubs on their low fat diets."

Without apparently trying, people on the Atkins diet were eating less than they would normally.

Controlling hunger

Scientists are now more interested than ever in what makes us eat less. They have concluded that there is something about the Atkins diet that controls hunger.

Research has shown that fat is the least filling food. But new work in Denmark is showing exactly what kinds of food may control hunger.

Professor Arne Astrup, from the Royal Veterinary & Agricultural University in Copenhagen, built a supermarket for a special study to find the secret of appetite control.

Professor Astrup's study focused on being able to eat as much as you want.

He put one group of shoppers on a high protein diet and one on a high carbohydrate diet.

He was surprised to find that the people eating more protein lost significantly more weight.

"The reason they lost more weight was because they consumed fewer calories, despite the fact they had free access to all the food they wanted."

Increasing the amount of meat, fish and eggs in the diet may not only be the answer to our hunger pangs, but the secret to how the Atkins diet works.

Perhaps without realising it, Dr Atkins stumbled across the secret of appetite control, by discovering a high protein diet.

The programme also investigates whether or not the Atkins diet is dangerous.

With no long term studies on the diet, any possible health risks of the diet are, so far, unproven.

Horizon: The Atkins Diet was broadcast on Thursday January 22nd at 2100 GMT on BBC Two.