Low-Carb Diets

Though it seems like the Atkins craze is dying down, there is still a great deal of misinformation with regards to low-carbohydrate diets.  The first issue is weight loss.  Low-carb diets often produce rapid initial weight loss compared to ther diets.  But does this weight loss last over the long-term?

The short answer is no.  There are a number of studies on this, but here is one and here is another.  Almost all diets, whether they are low-carb, low-fat, or other types, usually fail to show any significant long-term weight loss because they focus on energy intake and not energy expenditure.  Exercise is needed for any real long-term weight loss.

What about low-carb diets and cholesterol?  Here is nice meta-analysis on the subject.  Low-carb diets lead to lower triglycerides and higher HDL (good) cholesterol, but more LDL (bad) cholesterol than low-fat diets.  And if you look deeper, you'll find that "Mediterranean" diets outperform both the low-fat and low-carb approaches in terms of cholesterol imrpovements.

Another topic is whether low-carb diets offer any special benefits as far as preventing (or treating) diabetes.  If someone has diabetes, then by definition they have trouble processing carbohydrates.  An obvious solution would be to just limit the amount of total carbohydrate that's consumed.

But this is too simplistic in my view.  As discussed in an earlier post, the problem is not the total amount of carbohydrate but the type.  Moving a person from a high-glycemic diet to a low-carbohydrate diet would certainly improve their diabetes status, but is that the optimal treatment?  In my opinion, no - they are better off having a normal amount of "good" carbohydrates in their diet instead.

For example, in this study increasing the amount of carbohydrate from 40% of total calories to 55% led to improvements in insulin sensitivity.  You can also look at long-term eating patterns and see this, as for example this study showing vegetarians have higher insulin sensitivity than omnivores.

In summary, there is no reason in terms of health to follow a low-carb diet: 1) it doesn't lead to significant weight loss, 2) it doesn't lead to optimal cholesterol levels, and 3) it isn't the best treatment for diabetes.  A Paleo or Mediterranean diet (with moderate fat and quality slow-release carbs) is a much better dietary model and fits with our genetic heritage.