Technically pescetarians can do this diet. (I'm one too!) But in my opinion, it is so restrictive that it almost drove my husband and I insane after 1 week of following it. Here is what pescetarians are allowed to have:
Certain types of fish Shellfish Nonfat milk Nonfat plain greek yogurt Boiled eggs Splenda Oat "galettes" which have to be cooked every day Tofu - it's unclear whether unlimited quantites of this is allowed Lemon juice Herbs
To do the diet and not go insane like us, you'd have to be willing to cook every day, and you'd have to be pretty creative since the book doesn't have many recipes in it. I couldn't keep up with the oat galettes, so we started having plain yogurt with oat bran and Splenda in it instead. Reminiscing about this makes me nauseous, but I will say the diet did work - I lost about 7 pounds in 7 days. If I did do this again, I would follow his alternate plan of 2 days of "pure protein" and then 5 days of regular food, repeat (I only wanted to lose 20 pounds). I have bad memories of hurriedly throwing together a lunch of plain tofu cubes, lemon juice and herbs! You definitely need to be willing to plan meals ahead of time! I think if I wanted to lose weight again, I would go vegan instead or just reduce my portion sizes. Hope this helps!