Research Weighs In
Its not the carbs but the calories that cause folks on diets like Atkins to lose weight: That was the headline generated last spring from a study published in The Journal of the American Medical Association. Many nutritionists rejoiced as their predictions were confirmed by this study that demonstrated people lose weight on low-carb diets because they eat fewer calories. The bottom line for weight loss is that you must burn more calories than you consume, regardless of where those calories come from -- or so we thought.
But then another study was presented at a North American Association for the Study of Obesity meeting. Lead author Penelope Green, of Harvard University, suggested that people who ate a low-carbohydrate diet could actually consume more calories -- 300 more -- than people on a low-fat diet, yet lose the same amount of weight.
Even the study's authors cautioned that these results were preliminary, based on a very small study (of 21 adults), and that more research was needed. It's also noteworthy that this study was not published, and that the Robert Atkins Foundation (the same Atkins of low-carb diet book fame) was its sponsor.
Other studies have had similar results.
- A 2002 Duke University study showed that obese volunteers who followed the high-fat, low-carbohydrate Atkins diet for six months not only lost more weight, but they also improved their cholesterol levels more than volunteers on a low-fat, high-carbohydrate diet.
- Last May, researchers from the University of Pennsylvania reported that study participants following the Atkins diet lost slightly more weight over six months than people on conventional low-fat diets. The low-carb, high-protein diet was associated with greater improvement in some risk factors for heart disease, but there was no difference in weight loss between the two diets at one year. The study included 63 people and was reported in The New England Journal of Medicine.
- Last April, University of Cincinnati investigators reported that women following a low-carbohydrate diet for six months lost more weight than women following a low-fat diet. Writing in the Journal of Clinical Endocrinology, the researchers concluded that the low-carb diet appeared to have no negative effect on cardiovascular risk.
- A small study reported in the Journal of Pediatrics last March showed that teens on a low-carbohydrate diet lost more weight than those on a low-fat diet. The researchers reported that, contrary to their hypothesis, the diet did not appear to harm cholesterol levels over a 12-week period.
At the same time, some dieters who have followed low-carbohydrate regimes have reported health problems ranging from constipation to heart problems, according to the activist group Physicians Committee for Responsible Medicine.