> You're assuming a meat-based diet is automatically healthy

I'm asserting that it's harder to be nutrient deficient given a meat/fish-based diet. The only "work" in this diet is not eating too much.

> western diet is strongly linked to all of our most deadly diseases

Mostly due to overconsumption, not due to the composition of the diet. Controlling for caloric intake eliminates most differences in health outcomes between the various diets, assuming no nutrient deficiencies are present.