I'm doing it right now. It works really well. I lost 30 pounds on it a couple of years ago and kept most of it off until late last year.
I think the food is healthy and the plan is sound. My only issue is it's very hard to cook flavorful food with all the restrictions (no salt, no sugar, no fat, no dairy...). You really have to be a creative cook. It also requires a lot of planning because you are eating measured portions 5 - 6 times per day.
I've lost 10 pounds in the past 4 weeks and a friend that is doing it with me (male) lost 15 pounds.
I do like that there is no counting calories and no guessing what you should be eating at different times during the day. I also like that you are eating every 2-3 hours.
Here is an average day for me:
Breakfast: 1/2 grapefruit and egg whites equivalent to two eggs
Mid morning meal: 1/2 grapefruit and egg whites equivalent to two eggs
Lunch: 2 oz of chicken breast, 1 cup of vegetables and 1/2 a cup of rice
Mid afternoon meal: 2 oz of chicken breast and 1/2 cup of rice
Dinner: 2 oz of chicken breast, 1 cup of vegetables and 1/2 a cup of rice
Optional meal: 1/2 a grapefruit
As you can see, the food can get boring fast unless you plan way ahead and make several dishes to give yourself variety through the day.
I highly recommend this program because you will see results whether you are exercising or not.
When I first did it, I was 162 pounds and lost 25 pounds in the first 11 weeks. After that, I started exercising and doing the program 5 days per week and lost 13 more pounds slowly. I went from a size 12 to a size 4.
I'm back at 140 now and want to get down to 130 to fit in my clothes. It was too hard to stay at 125. I don't think it was a happy weight for my body.
Good luck!
Silke