The research, published in the peer-reviewed medical journal Annals of Internal Medicine, revealed that cardiovascular risk factors, such as blood pressure and lipid (cholesterol) levels responded much better with the low-carb diet. Both diets produce near identical weight loss when combined with comprehensive behavior treatment

Basically – it would appear that both diets are equally good for reducing your weight, but the low-carb diet helps to protect you from potential cardiovascular diseases far more effectively.

The findings may come as a big surprise to many people who would instinctively link a low-carb diet with worsening cardiovascular risk factors.

Three hundred and seven patients were randomly assigned to either a low-carbohydrate (n=153) or low-fat (n=154) diet together with a behavior treatment program. The patients weight after two years was the primary outcome, but other effects were also measured throughout the study period.

At 3, 6 and 1 year, the patients were evaluated for:

• Weight
• Serum lipid concentrations
• Blood pressure
• Urinary ketones
• Bone mineral density
• Body composition

Amongst the participants in the two diet groups, the researchers found:

• Weight – no significant differences at any point during the study. About a 7% weight loss after two years in both groups.
• Body composition – no real differences at any point during the study
• Bone mineral density – no material differences at any point during the study
• Good cholesterol levels – double the increase among the low-carb diet group as compared to the low-fat group after two years. 23% and 11% respectively.

Gary Foster, PhD, director of the Center for Obesity Research and Education at Temple University, Philadelphia, said:

I think an important outcome from a study like this is to think about which diets fit best for which people. This study would suggest that perhaps for those with low HDL-cholesterol levels to begin with, that a low-carbohydrate approach to weigh loss may have some dvantages.

Foster added:

At the end of the day, behavior interventions are key. Dieters should be less concerned about what diet they follow, and more concerned with employing effective behavioral strategies, such as recording what they eat, logging their exercise, and limiting the triggers for overeating, like watching TV or eating in the car.

“Weight and Metabolic Outcomes After 2 Years on a Low-Carbohydrate Versus Low-Fat Diet – A Randomized Trial”
Gary D. Foster, PhD, Holly R. Wyatt, MD, James O. Hill, PhD, Angela P. Makris, PhD, RD, Diane L. Rosenbaum, BA, Carrie Brill, BS, Richard I. Stein, PhD, B. Selma Mohammed, MD, PhD, Bernard Miller, MD, Daniel J. Rader, MD, Babette Zemel, PhD, Thomas A. Wadden, PhD, Thomas Tenhave, PhD, Craig W. Newcomb, MS, Samuel Klein, MD
Annals of Internal Medicine August 3, 2010 vol. 153 no. 3 147-157

The drug, alli, is a lower dose version of the same medication which doctors prescribe to obese people, but can be purchased over the counter after a brief consultation with a pharmacist.

alli increases the weight lost achieved through a low calorie diet by 50 per cent, so those who would lose two pounds in a week following a low-fat diet would lose three pounds if they took Alli three times a day.

Alli capsules, a new clinically proven over-the-counter weight loss aid produced by GlaxoSmithKline

Experts have said the drug will be useful in giving people a kick start to their weight loss but it is not a magic pill, has some unpleasant side effects and should not be seen as a quick fix.

Tam Fry, chairman of the Child Growth Foundation and board member of the National Obesity Forum, warned that there is ‘huge potential’ for the drug to be misused and said under no circumstances should it be given to children.

He said: “Adults could get alli by going through the consultation themselves and give it to their children and that is totally wrong, there is huge potential for that to happen.”

The drug prevents the absorption of around 25 per cent of fat in food and carries it from the body, so there is concern that if children took it they would lose vital vitamin D which is needed for healthy bones.

alli, made by GlaxoSmithKline, is licensed for adults with a body mass index (divide weight by height squared) of 28 or more. It contains 60mg of orlistat, which is the name of the higher dose prescription-only version.

Glenys Jones, who holds a degree and masters in nutrition and works at the Medical Research Council’s Human Nutrition Research centre at Cambridge University, said: “It is not a magic pill, if you don’t make the changes it won’t do it for you. You must follow a low-fat diet with it and by doing that some people will become more aware of what they are eating and make the changes needed to sustain the weight loss. We need to make sure that pharmacists are properly trained to make sure people have the right BMI and receive the advice about healthy eating and exercise as well as the side effects.”

She said it should be used for at least three months which made it quite expensive.

A spokesman for the National Pharmacy Association said pharmacists have been through ‘robust’ training from GlaxoSmithKline.

John Turk, NPA Chief Executive said: “Our members report that many people seek advice from pharmacists on how best they can lose weight. By making orlistat a pharmacy medicine, pharmacists now have a new way of encouraging safe, steady and sustained weight loss in the general public.”

James Hallatt, General Manager GlaxoSmithKline Consumer Healthcare UK, said: “Obesity and overweight are a major concern of our society and people need help. alli offers a clinically proven way to help people lose weight. alli is not a magic bullet – users must be committed to weight loss; alli, when added to a reduced calorie, lower-fat diet, can help people lose 50% more weight than dieting alone. alli launched in the US in June 2007 and has been well received by millions of people, we are very excited about the opportunity to help overweight people in the UK achieve their weight loss goals.”

by Rebecca Smith, Medical Editor
Telegraph.co.uk