Will the debate about the relative virtues of low-carbohydrate vs. low-fat diets for weight loss never end? All the chatter is doubly annoying since, until now, all the talk is backed up by little data comparing the two diets.
A recent review of multiple scientific studies (a "meta-analysis") examined the findings of five controlled clinical trials involving 222 people on low-carbohydrate diets and 225 on low-fat diets. On the low-carb diet, carbohydrates were limited to 60 grams a day; on the low-fat diet, total fat was less than 30 percent of calories.
The results? At the six-month mark, those on the low-carbohydrate diet had lost more weight but, by the end of one year, followers of both diets had lost comparable amounts.
The results from this meta-analysis also showed that people on the low-carbohydrate diet had small but statistically significant increases in both total and harmful LDL cholesterol; on the plus side, their protective HDL cholesterol rose significantly while their triglycerides fell. (One major concern about following a low-carb diet for an extended time: their high protein and fat content can potentially cause a rise in cholesterol levels.)
These results will not end the debate because it's still unclear which variable will have the greater impact on coronary heart disease among low-carbohydrate dieters: the higher LDL cholesterol (harmful) or the increased HDL cholesterol (helpful). Indeed, neither of these changes may have any long-term impact, since most people discontinue low-carbohydrate-and other-diets after a relatively short time.
Perhaps the most important finding is that following either type of diet led to comparable amounts of weight loss.
