> Cut out vegetables from your diet, for example, and you will experience serious intestinal distress when you reintroduce them.

I've actually done that[1], and experienced the complete opposite. I found myself dreaming about eating broccoli, and absolutely craving all kinds of vegetables. When the diet ended I ate lots of vegetables -- and certainly no intestinal distress when eating them.

[1] - "Velocity Diet": the very definition of fad diet, which basically consists of drinking a protein shake 5 times a day for 4 weeks, with 1 solid meal per week. It worked, but I'd never ever do it again, nor recommend anyone ever do it.