I know there is a separate culinary definition of what a fruit is that I don't really understand. Like under some definitions a tomato is a vegetable. Maybe he is working off that but botanically a pepper is a fruit. His point would probably stood better if he used spinach as an example of a vitamin C rich green.

Either way, these fad diets always scare me. I wouldn't touch anything that draws simple, arbitrary, counter-intuitive lines on what foods you can and can't have. The body is good at knowing what it needs and what it doesn't. Support it with a little bit of knowledge and self-discipline and it will serve you well. I guess a well balanced diet is old fashioned and people just want to try and cheat the system somehow.