It doesn't take that much to come up with an educated argument about which diet to follow to be honest. All it takes is balance. Best diet you can follow is the Mediterranean diet which consists of vegetables, grilled meat or fish and (important) a portion of carbs because you need energy. In other words, your plate has to have half of it containing vegetables and then a quarter of proteins and carbs. Just remember that extremism doesn't get you anywhere.
The problem today is that we have processed and fast food that is disrupting the diets. Even the Mediterranean folks don't follow a Mediterranean diet anymore because of these fast food producing chains. And sedentary habits have a lot of impact on it too.
But Bla Bla Bla Bla it's a topic of another thread.
Só about groshens abs...