The Mayo Clinic Diet blog

Low-fat vs. low-carb

By Donald Hensrud, M.D. September 24, 2010

Over time, many different types of diets have been popular, including low-fat and low-carb diets. Some years ago, low-fat was the mantra. More recently low-carb has been the rage, promising effortless weight loss while eating all the high-fat foods you want.

Low-fat usually means high-carb but doesn't always mean low-calorie if someone eats too many carbs, particularly processed carbs that are more concentrated in calories. Conversely, low-carb usually means high-fat. Many people who have tried this type of diet know it can be difficult to continue for a long time because a lot of good tasting fruits and other carbohydrates are off limits and high-fat goodies do get a little old after a while.

The most important factor related to weight loss is not low-fat or low-carb — it is calories. Either type of diet could lead to weight loss if total calorie intake is low.

There have been a number of studies comparing weight loss with these two types of diets. In general, low-carb diets may result in a little more weight loss in the first 3 to 6 months. However, after 1 to 2 years there isn't much difference. What's interesting is that the amount of weight loss varies widely among people following either diet. So which type of diet you choose may matter less than whether you stick to it.

Another important factor is the healthfulness of the diet — and both of these types of diets could be healthy or unhealthy, depending on the types of fats and carbohydrates that are consumed. Other things that may influence how long a diet is followed include taste, satisfaction, satiety and practicality.

The Mayo Clinic Diet emphasizes healthy carbs (fruit, and whole-grain products) and fats (olive oil, nuts and vegetable oils). By consuming lower amounts of less healthy carbs (sugar, white flour, and other processed carbs) and less healthy fats (saturated and trans fats), total calorie intake is lower. Because the emphasize is also on good tasting foods, unlimited vegetables and fruits to achieve satiety, and making lifestyle changes and not a short-term "diet," the Mayo Clinic Diet can be easier to follow long-term.

What have been your experiences with low-fat or low-carb diets?

Sept. 24, 2010