Right out of the gate we have the "Attack Phase", where you are only eating proteins and 1.5 tbsp of oat bran. No other carbs allowed! From what I have found, this phase lasts no longer than 7-10 days. In the second phase ("Weight Loss") your palate becomes a little less snobby and can take vegetables, but no fruit. You are also allowed to bump that 1.5 tbsp of oat bran up into a party-starting 2 tbsp! This phase doesn't seem to have a defined timeframe; rather, you will allegedly lose weight until you hit your goal weight. Once you have reached your desired weight, you enter the third phase, labelled "Stabilization". Things get more familiar here, where you are allowed things like fruit, cheeses, carbs, and even red wine (only fitting, since a Frenchie developed this diet!) Again, time seems to have a very subjective sense of government here. You are advised to stay in this phase "5 days for every pound of weight that you lost during Phase 2."
Here's where things get interesting; in the last phase of the diet you get to "Cruise". What does this mean for you? 6 days of eating whatever you want, followed by one day of going back to the "Attack" diet of only protein and oat bran. This last phase allegedly will be sufficient for life. The idea is that once you have gone through the phases, you can combine this diet with 20-minute walks daily, and maintain an active lifestyle.
This diet might look very similar to Atkins; that's probably because it is very similar to it. With the elimination of carbohydrates, fruits, vegetables, alcohol, and desserts, I have no doubt that you would lose weight, and pretty quickly for that matter. Unfortunately, I have the same concerns with this diet as I do with so many other fad diets out there: It is unhealthy to cut a macro group entirely out of your diet, plain and simple. Asking your body to function like this carries with it severe health risks, and a host of unpleasant side effects. Like this. And this. And this. There are others, but I don't want to go into link over-kill here...Point being, I can reasonably see cycling your intakes of certain maconutrients, but I can't support just getting rid of them and expecting everything to be fine. A better idea would be to eat balanced meals that include all food groups throughout the day, and moderate your levels of each depending on your goals. Low-cal for weight loss, cycle carb/protein for fat loss, hi-cal for weight gain.
It should probably be added that there is a huge asterisk stuck onto the part in the 4th phase where you eat "whatever you want". The creator of this diet wasn't being an idiot, just French. So yes, he probably intended for you to have the occasional dessert, and glass of wine, some crepes, that stuff. He probably didn't mean, "Eat your fucking face off in the Cheesecake Factory." More along the lines of, "Be reasonable, there's no reason we can't eat in moderation." But he did it with his big baguette-loving accent.
On a side note, I LOVE their ending comments; combine this diet with a healthy lifestyle...no shit, really? Take a look at any of the ads you read, or diets you research, it's such a cop out and I love it. It's a completely valid point and I 100% support it, but it's always funny to me how you can "Take this NEW PILL that will TRANSFORM YOUR LIFE when combined with a healthy diet and regular exercise." Gets me every time :-)
Anyways, I hope this was helpful for you, and if you have any questions regarding your nutrition, or diets you have heard of and are considering trying, leave a comment on this post or use the link on the side and I will help out as best as I can!