http://www.newscientist.com/news/news.jsp?id=ns99995003 Longest scientific study yet backs Atkins diet 12:21 18 May 04 NewScientist.com news service The claimed benefits of the controversial low-carbohydrate Atkins diet have been reaffirmed in two new studies, one of which is the longest study to date. "I think it's good news for Atkins dieters," says Linda Stern, who led the first study of 132 obese patients at the Veterans Affairs Medical Center in Philadelphia, US. The diet was devised by the late US doctor Robert Atkins. To lose weight, devotees avoid carbohydrates and consume more protein and fat instead. Both new studies found that subjects on the Atkins diet shed significant amounts of weight without harmful effects on blood fats and sugars. But the studies have failed to silence critics of the diet, who want the US government to investigate alleged adverse effects. Stern's year-long study (Annals of Internal Medicine, vol 140, p778) was twice the length of any previous study. Half the patients followed the Atkins regime, limiting daily carbohydrate intake to just 30 grams. The rest tried losing weight through a conventional low-fat diet much richer in carbohydrates. By the end, both groups had lost about the same amount of weight, between five and eight kilograms for the Atkins group and three and eight kilos for the low fat group. But the Atkins dieters lost almost all their weight in the first six months, then remained at a steady weight. Stern says that this pattern of rapid weight loss matches that seen in an earlier but shorter study of Atkins dieters, by Gary Foster's team at the University of Pennsylvania in May 2003. "I'm impressed that they didn't gain it all back," says Stern. Compared with the low-fat group, Atkins dieters also had lower levels of triglycerides, potentially harmful blood sugars which can trigger heart disease. Concentrations of beneficial high density cholesterols (HDLs) also held up better in the Atkins group. And these favourable changes remained till the end of the study, suggesting that there might be lasting benefits. "But what we really need is a study showing whether people on the low-carbohydrate diet for years have different odds of heart attacks, strokes and diabetes," she says. A second, six-month study on 120 overweight patients at Duke University Medical Center in Durham, North Carolina, echoes the first, with low-carbohydrate dieters shedding an average of 12 kilos, twice that lost by those on a low-fat regime (Annals of Internal Medicine, vol 140, p769). And the pattern of blood fats and sugars mirrored that in Stern's study. "Over six months, the diet appears to be relatively safe, but we need to study the safety for longer durations," says Will Yancy, head of the Duke team. But critics highlight some negative findings from the Duke study. "This new evidence confirms that levels of 'bad' cholesterol worsen in a substantial number of low- carbohydrate dieters," said Neal Barnard of the Physicians Committee for Responsible Medicine, a vegan lobby group in Washington DC. "And the supposedly dramatic benefits of the diet do not hold up over the long term," said Barnard, referring to the end of weight loss after six months in the Stern study. Although broadly supportive of the Atkins regime, Yancy warns that the diet could pose risks including the higher "bad" cholesterol, bone loss and kidney stones. Because of this, he discourages first-time dieters from using the regime. Andy Coghlan **************************************** http://news.bbc.co.uk/1/hi/health/3722221.stm Scientists endorse Atkins diet Following a low-carbohydrate, high-protein diet is a more effective way to lose weight than following a low fat diet, say US researchers. Two studies published in the journal Annals of Internal Medicine found weight loss was greatest when people followed an Atkins-style diet. Cholesterol levels also seemed to improve more on a low-carb diet compared to a low-fat diet. However, the research was funded by the Robert C Atkins Foundation. And critics say there are still serious doubts about the long- term effect on health of adopting such diets. In the first study, researchers at Duke University Medical Center in Durham, North Carolina, assigned 120 obese volunteers to either a low-carbohydrate, high-protein diet or a low-fat, low-cholesterol, low-calorie diet. After six months, the people on the Atkins-style diet had lost an average of 26 pounds, compared to an average of 14 pounds in the conventional low-fat diet group. The low-carbohydrate, high-protein diet also had a good effect on fat levels. The Atkins dieters lost more body fat, lowered their triglyceride levels and raised their "good" HDL cholesterol levels more than the low-fat dieters. In the second study, researchers at the Veterans Affairs Medical Center in Philadelphia followed 132 obese adults who were randomised to either low-carbohydrate or low-fat diet groups. Again, after six months the people following the low- carbohydrate diet lost the most weight and had improved fat levels. However, at 12 months both groups had lost similar amounts of weight. The low fat group had continued to lose weight from six to 12 months while the average weight in the low-carbohydrate group had remained steady after six months. Lead author of the Philadelphia study Dr Linda Stern said: "I think a low-carbohydrate diet is a good choice because much of our overeating has to do with consumption of too many carbohydrates." But she said more research was needed to see if a low- carbohydrate diet remained safe and effective over the longer term. In an accompanying editorial, Dr Walter Willett, from the Harvard School of Public Health in the US, said: "We can no longer dismiss very-low-carbohydrate diets." But he added that such diets should include healthy sources of protein and fat and incorporate regular exercise. "Patients should focus on finding ways to eat that they can maintain indefinitely rather than seeking diets that promote rapid weight loss," he said. Dr David Haslam, chairman of the National Obesity Forum, said: "There is no doubt that if low-carbohydrate, high- protein diets are followed properly you will lose weight. "What's always been questioned is the long term efficacy of such diets and in the short term, with weight loss, there are certain risks in certain patients - like patients with renal problems." "There's still no long term data about the efficacy and you can't stick on that type of diet for long because it's unpalatable," he said. Dr Haslam called for more research spanning five to six years rather than months. He said the best diet was still a healthy, balanced diet cutting out excessive fat. "One thing the Atkins isn't is balanced. It's not what the body expects and that's why we don't know the long term changes," he said. Dietzmina Govindji, of the British Dietetic Association, also warned people against thinking Atkins, or other similar diets, were the best way to lose weight. She said: "Do not be sucked in by the cabbage soup diet and other fad diets. "The thing to remember about all these quick-fix diets is they do help you lose weight very, very quickly but often you will put it back on very, very quickly and they often miss out on whole food groups, so you are not getting the full range of vitamins and minerals you need."