A report published in the prestigious Archives of Internal Medicine (Feb 13, 2006) adds more evidence to the accumulating research showing that low-carb diets get weight off. The report- which analyzed the findings of five major studies comparing low-fat and low-carb diets– found that low-carb diets do indeed help people shed pounds more quickly than low-fat regimines.
Researchers in the United States and Switzerland analyzed five large studies comparing a total of 447 middle-aged Americans- 222 followed a low-carb diet and 245 followed a low-fat one. After six months, those following the low-carbohydrate diet lost more weight than people on a low-fat diet. While the analysis did show that weight loss for both groups tended to equalize after a year, the evidence was clear that low-carb is a viable alternative for many people, and produces weight loss at least as successfully- if not more so- than low-fat regimines. And it seems to do it quicker, at least in the short term. The study comes on the heels of a new survey from Opinion Dynamics showing that fully 11 percent of the adult population in America is happily following the low-carb lifestyle.
At least as interesting as the weight loss in the study were the measurements on blood lipids. According to the study, neither blood pressure nor blood sugar changed in either the low-fat or the low-carb group, showing once more that a controlled carbohydrate diet performs just as well as a low-fat diet on these important measures. What’s more, on two critical measures it performs better. Both triglycerides and “good” HDL cholesterol were improved significantly more in the low-carb group. Some research has shown that the ratio of triglycerides to HDL cholesterol is even more predictive of coronary heart disease than traditional measures of cholesterol alone. By lowering triglycerides and raising HDL cholesterol, the low-carb diet improved that ratio and seriously outperformed the low-fat regimen.
It’s true that the low carb group had a slightly greater rise in “bad” LDL cholesterol than the low-fat group, “but healthy triglyceride and HDL levels may outweigh the negative effects of LDL cholesterol, which in the low-carb group represented just minor increases”, said William Yancy, MD, an author on the study and a professor of medicine at the Department of Veterans Affairs and Duke University.
One fact that seemed to get lost in the news reporting on this study was that the low-carb groups did not restrict their calories. “Low-carbohydrate, non-energy-restricted diets appear to be at least as effective as low-fat, energy-restricted diets in inducing weight loss”, said the study summary. We at Atkins still believe that calories can’t be ignored, and too many calories are undeniably the culprit in weight regain. Nonetheless, the current study does seem to show that it’s easier to lose weight on a low-carb regimen than on a calorie-restricted low-fat one.
Part of the reason just might be protein. In a related study also out this month, Dutch researchers reported that consuming nearly one third of your daily calories as lean protein revs up a person’s metabolism during sleep, as well as boosting the burning of calories and fat during the day. Moreover, when the study’s participants- all women of healthy weight- ate more protein, they said they felt fuller, more satisfied and less hungry than when they consumed a diet with the typical amount of protein, (usually only 10% of calories). Adding more lean protein to your daily fare “enables you to reach the same level of (fullness) that you are used to with about 80% of your (usual calories)”, said Dr. Margriet Westerterp-Plantenga, the study’s lead author.