Low-Carb Diets Work, but Safety Still an Issue
Not Enough Research to Declare Low-Carb Safe in the Long Term
Sept. 2, 2004 -- The Atkins diet and other low-carb diets help people lose weight -- at least in the short term. But the long-term safety of low carb diets is still an issue, Danish nutrition experts argue.
Nutrition expert Arne Astrup, MD, PhD, heads the Institute of Human Nutrition at the Centre of Advanced Food Research of the Royal Veterinary and Agricultural University in Copenhagen, Denmark. Astrup and colleagues ask in the Sept. 4 issue of The Lancet, "Atkins and other low-carb diets: hoax or an effective tool for weight loss?"
After reviewing the scientific literature, the Danish experts say the Atkins diet is no hoax. They say Atkins and other low-carb diets work better than low-fat diets -- for up to a year -- in helping people lose weight and lower their risk of heart disease and diabetes. And the diets seem safe, too. What's the catch?
"Our paper seems to be kind of an endorsement of the Atkins diet -- but not really," Astrup tells WebMD. "I say it is apparently safe."
Low-Carb Diets: Safety Issues?
Eventually, Astrup says, low-carb diets have the same problem as other diets: They're too restrictive for people to stay on for the rest of their lives.
"After six months, from six months to one year, the efficacy of low-carbohydrate diets seems to go away," he says. "After one year it is still better than low-fat, high-carbohydrate diets -- but people are regaining weight. They do this on all diets, so there is no reason to blame Atkins. This is probably due to lack of adherence."
What worries Astrup is that low-carb diets don't, in his opinion, have enough fruits, vegetables, and whole grains for long-term health.
"What we are more concerned about is that people on low-carbohydrate diets begin to complain about side effects: headache, muscle weakness, and cramps and diarrhea. This is consistent with carbohydrate deficiency," he says. "On Atkins, you are far below the minimum requirements -- 150 grams a day -- of carbohydrate. So the organism and the brain are probably suffering from the lack of glucose to burn, and that is disturbing the normal function of the tissues."
Or maybe the real problem is that Astrup doesn't understand the Atkins diet, suggests Mary Vernon, MD. Vernon is co-author of Atkins Diabetes Revolution, a member of the Atkins Physicians Council, and vice president of the American Society of Bariatric Physicians. She notes that the Atkins diet severely restricts carb intake only during the first two weeks.
"Many of the things he discusses apply only to the two-week induction period," Vernon tells WebMD. "For me, the great thing about Atkins is it allows people to find their own level of carb tolerance. You go down to 20 grams of carbs at first, then you go back up until you find your own level. People with diabetes have to go slower. But in both cases, you don't stay at 20 grams of carbs for the rest of your life. An Atkins maintenance plan would have whole grains like barley and vegetables like baked squash at various levels according to your personal metabolic needs."