Many people associate a plant based diet with vegetarianism or veganism, and while these diets are essentially plant based, the actual scientific definition does not always indicate a complete restriction of animal products. The type pf diet you are on does not always indicate how healthy you will be. Its the overall food patterns and choices that predict overall health. Studies have shown that the more plants we eat, and the less animal products we eat, the lower our disease risk. Enter the realm of the flexitarian, the not-quite but mostly vegetarian.
There are basically 2 types of plant based diets:
Completely plant based, or vegan diets that exclude all animal protein
A partially plant based diet that includes some form of animal protein (this includes vegetarians, lacto and lacto-ovo vegetarians, pescatarians and omnivores)
In either event, as long as the diet contains mostly plants, we can consider it plant based.
Both of these diets can be labelled healthy or unhealthy depending on the choices. A vegan diet that is low in vegetables but high in processed carbohydrates, fizzy drinks and sugar is not necessarily going to give health benefits, while a well planned Omnivorous diet will offer benefits.
We all need to be eating more vegetables, fruits, wholegrains, plant based proteins and natural oils for health. A plant based diet can still contain a small amount of unprocessed animal products, and still be labelled as such. If you don't choose to be 100% plant based, you can still make more plant based choices and enjoy some flexibility while still labelling yourself as a plant based eater! Thats my 2c worth anyway.