1 is 2 Fat Weight Loss Guide
Atkins diet works faster initially than low-fat diet, and may improve blood fat levels, say studies
OBESITY rates are rising, but science has barely weighed in on the best way for people to shed fat. That state of affairs is starting to change, and doctors are getting a surprise or two.
THE Atkins diet promotes protein-rich foods such as meat, eggs and cheese over traditional diet basics like pasta, bread and vegetables.
The popular carbohydrate-slashing Atkins diet received a dollop of endorsement from two studies after years of being pooh-poohed by health specialists.
The studies, published in the Annals of Internal Medicine, showed that the meat- and fat-rich regimen caused faster weight loss in the short term than a conventional low-fat diet.
More importantly - because many had feared that the diet, even if slimming, might unfavourably affect cholesterol levels and be bad for the heart - the low-carbohydrate regimen also seemed to improve the dieters' blood fat profiles.
But Atkins, like every other diet, is no miraculous fat-melter.
The longer of the two studies suggested that a low-carb regimen might be harder to maintain beyond six months, compared with a low-fat approach. By the end of the year, the low-fat dieters had caught up and lost the same - very modest - amount of heft.
In addition, although on average people on low-carb diets did not experience increases in their so-called 'bad' (or LDL) cholesterol levels, about 30 per cent of them did.
Even with these caveats, 'we can no longer dismiss very-low-carbohydrate diets', said Dr Walter Willett, a nutritional epidemiologist at the Harvard School of Public Health, in a written editorial accompanying the papers.
To maximise the diets' healthfulness, he added, people should avoid going wild on fatty bacon and red meat, and should opt instead to eat healthy oils (monounsaturated and polyunsaturated fats) and get protein from fish, beans, nuts and chicken.
The weight-loss regimen popularised by the late Dr Robert Atkins - rich in meat, eggs and cheese but almost bereft of grains, potatoes and fruit - is highly popular but had not been tested in a scientifically rigorous way until earlier this century, when two studies reported that very obese and moderately obese people lost more weight initially on the Atkins diet than on a conventional diet.
The studies published bolster and extend these findings.
Conducted at the Philadelphia Veterans Affairs Medical Centre, the first study enrolled 132 severely obese adults with an average weight of 130kg. Many of those in the study had diabetes or other risk factors for coronary artery disease.
Roughly half of them were put on a low-fat diet and told to eat 500 fewer calories a day.
The others followed a regimen in which they were to limit their carbohydrate intake to less than 30g daily, but were not told to count calories or fat.
The scientists reported last year that at six months, the low-carb group had lost an average of 5.8kg, compared with 1.8kg for the low-fat group.
Last month, the scientists reported that after one year, individuals on the Atkins-style diet largely kept the weight off but did not continue to lose more weight.
The low-fat group continued to lose weight slowly over the course of the year.
Total weight loss for both groups over the year was slight: 4.9kg to 8.6kg for the low-carb group, and 3.1kg to 8.6kg for the low-fat group.
The study also found that diabetic patients improved control over their blood sugar levels using the low-carb approach.
The second investigation was funded by the Robert C. Atkins Foundation, although the foundation did not take part in the study or its analysis.
Conducted at Duke University Medical Centre in Durham, North Carolina, it enrolled 120 moderately obese adults who had high-blood cholesterol levels.
At six months, participants who followed a low-carb approach had lost an average of 11.7kg, compared with 6.3kg for the low-fat group.
Weight loss was not the only effect of these diets. Both studies found that levels of triglycerides - blood fats that are risk factors for heart disease - fell further in the low-carb group than in the low-fat group. Levels of HDL, or 'good', cholesterol also seemed to improve more in the low-carb group.
Still, experts said more studies were needed to ensure that the HDL lipid change was favourable and that the higher amounts of fat consumed on an Atkins-style diet would not increase a dieter's risk of heart disease.
The American Heart Association issued a statement expressing concern about the safety of the diet given its richness in saturated fats.
To be safe, people on an Atkins-style diet should have their blood lipids monitored regularly in case their 'bad' cholesterol goes up, said Dr William Yancy, assistant professor of medicine at Duke and lead author of the study there.