For awhile it was a battle without good research on either side: proponents of low-carbohydrate diets claimed they achieved better weight loss than with any other plan, while many health experts kept insisting that calories – not carbs – matter for weight loss. Now we have some good studies on the effectiveness of low-carb diets. The results: Both sides were right. For short-term results, low-carb diets do seem to offer some advantages. However, in the long run, it’s calories that count.
Three well-controlled studies now show that after following a low-carb diet for six months, people generally have lost more weight than those on more traditional low-fat diets. In fact, average weight loss of those on low-carb diets is two to three times as much after six months. These diets also offered the advantages of producing greater drops in blood triglyceride levels. They improved blood sugar and insulin function in people who originally showed abnormalities. The increased blood cholesterol that experts expected generally did not show up. Fewer people dropped out of the low-carb diet groups at six months, too, maybe partly because of the encouragement they received from rapid early results.
However, two studies have now addressed the more crucial question of long-term results. Both studies show that one year from starting, there is no significant difference in the weight loss achieved by people on low-carb diets and those on conventional low-fat, low calorie diets. These reports suggest that once the six-month mark has passed, many people on low-carb diets begin to regain weight they have lost. Also, the improvements in insulin function that were strongest with low-carb diets at six months were equal for both diet groups after one year, and were strongly related to how much weight was lost.
Looking at the average weight loss, which was higher for the low-carb dieters, can be misleading. Although their average weight loss may have been greater at six months, not everyone on low-carb diets lost successfully. In fact, there was more difference in weight loss within each of the two diet groups than there was between them. In other words, what works for some people is different than what works for others.
Make your own individual plan
The real challenge is to find how you as an individual can best reach and maintain a healthy weight, while also achieving good health. Some people may do best in the short-term with a highly structured diet. Clear rules eliminating certain foods actually makes it easier for some people, because it avoids the tendency for eating “just a little bit” to slip into overeating. Other people find such structure intolerable.
Research suggests, however, that even people who like the black-and-white rules at first eventually find that they cause feelings of deprivation and a tendency to binge. Eventually, we each need to find the degree of structure and flexibility that works best for us.
Low-carb diets can also promote early success because their higher level of protein tends to keep people’s appetite satisfied for longer periods of time. This can be especially helpful for people who previously omitted protein at meals and snacked on carbohydrates every couple of hours. For long-term weight control and good health, people need to satisfy their hunger by eating meals that have moderate amounts of lean protein and adequate (but not excessive) portions of whole grains, plus plenty of vegetables and fruits. This kind of balanced eating provides the fiber and nutrients we need for lower risk of chronic diseases like cancer and better overall health.