After experiencing so many years of ridicule (now effectively past history) with the Zone diet, I never thought I would possibly criticize another new diet unless it was either dangerous or just plain foolish. The newest diet from France is both.
Called the Dukan diet, this program is a strange combination of the Atkins diet with a French twist. As usual, there are number of diet phases that have to be followed. The first one is downright dangerous as it recommends unlimited amounts of lean protein, 1½ tablespoons of oat bran and lots of water. The reason this phase is dangerous is because there are virtually no carbohydrates or fats to counterbalance the protein. My best estimate is in this first phase more than 90 percent of the total calories are coming from protein. This will overwhelm the liver's capacity to metabolize the excess protein leading to a condition known as “rabbit starvation” (1). This was a condition experienced by early Arctic explorers who only subsisted on lean protein. They quickly became dehydrated as the body desperately tried to excrete excess ammonia (the first breakdown product of protein) through the urine that could not be converted to urea by the liver. This leads to dehydration, diarrhea, nausea, low blood pressure and fatigue. At least on the Atkins diet there was a lot of fat coupled with the protein to help the liver metabolize the ammonia from the protein into urea that could be easily removed in the urine.
The dehydration from such a severely ketogenic diet explains the need for lots of water. As far as the oat bran, it contains virtually no carbohydrate, but lots of soluble fiber to help expand the stomach. Yes you will lose weight (primarily water) and insulin levels in the blood will drop dramatically, but you will reduce the elasticity of the blood vessels (2) and increase insulin resistance in the liver (3). The decrease in the elasticity of blood vessels increases the likelihood of a heart attack, (4) and the growing insulin resistance sets the stage for liver dysfunction that always promotes weight regain. This first phase is called the Attack Phase, I assume because it attacks your liver and your metabolism.
Phase 2 of this diet is just as wacky. Now you increase the oat bran to 2 tablespoons per day and have some vegetables every other day. This phase remains a highly ketogenic diet, meaning the liver and blood vessels are still in a metabolic mess. This is called the Cruise Phase. I guess this means you are cruising for a hard landing even though you are still losing weight.
If you last through the first two phases (about two months), you enter into the Consolidation Phase that is just as wacky as the Cruise Phase, but in the other direction. Now you can add non-starchy vegetables every day and a piece of fruit (I applaud these additions). But then why does this diet let the person start eating bread every day and rice and pasta twice a week plus two Porky Pig meals including dessert and wine (that's the French twist). It's like an insidious plot to demonstrate how quickly you will regain the lost weight, but now as newly synthesized fat. Of course, by following this Consolidation Phase, it is virtually guaranteed you will consolidate the lost weight into new stored fat.
Finally, there is the Stabilization Phase where you can eat anything you want (mac and cheese, fried chicken, etc.) as long as you eat only lean protein one day each week. Fat chance you will ever get there.
You probably won't die on the Dukan diet, but you will mess up your liver metabolism making it much more difficult to lose the resulting regain of fat mass on the Consolidation Phase.
I am frankly getting a cold sweat as I write this blog since I am sounding a lot like Dean Ornish yelling at Bob Atkins in the old days. But even Bob would say the Dukan diet is just plain stupid.
- Silsborough S and Mann N. “A review of issues of dietary protein intake in humans.” Int J Sports Nutr Exerc Metab 16: 129-152 (2006).
- Buscemi S, Verga S, Tranchina MR, Cottone S, and Cerasola G. “Effects of hypocaloric very-low-carbohydrate diet vs. Mediterranean diet on endothelial function in obese women.” Eur J Clin Invest 39: 339-347 (2009).
- Jornayvaz FR, Jurczak MJ, Lee HY, Birkenfeld AL, Frederick DW, Zhang D; Zhang XM, Samuel VT, and Shulman GI. “A high-fat, ketogenic diet causes hepatic insulin resistance in mice, despite increasing energy expenditure and preventing weight gain.” Am J Physiol Endocrinol Metab 299: E808-815 (2010).
- Yeboah J, Crouse JR, Hsu FC, Burke GL, and Herrington DM. “Brachial flow-mediated dilation predicts incident cardiovascular events in older adults.” J Am Coll Cardio 51: 997-1002 (2008).