I've recently switched over to a pesco-lacto-ovo-vegetarian diet. In case you don't understand the multiply-hyphenated word, that means that I eat vegetables, eggs, milk and dairy products, and fish (occasionally). So far, this diet really seems to work for me. I don't miss red meat at all. I was recently offered it (specifically, venison) and ate it only out of friendship. I do miss chicken a bit, but I've eaten it once or twice in the last couple of months and that seems to be all I really need.
How is this paleo? Most people would say it isn't. To become "truly paleo", I would have to drop the milk (have you ever tried to milk an auroch? NOT fun!) and probably most of the eggs. I would also have to stop eating beans as often.
"Diet" is a loaded word. My friend Webster helps here:
Main Entry: di-et
Function: noun
Etymology: Middle English diete, from Anglo-French; from Latin diaeta, from Greek diaita, literally, manner of living, from diaitasthai to lead one's life
Date: 13th century
1a habitual nourishment; the kind and amount of food prescribed for a person or animal for a special reason; a regimen of eating and drinking sparingly so as to reduce one's weight
2 something provided or experienced repeatedly
Look at the etymology of the word, its history. Look at the Greek; it means "manner of living". This doesn't just include food; it could include food as well as exercise, mental stimulation, job, family, and more.
Your diet isn't just "what you eat"; it's "who you are".
Have a good "diet".