Is it proven thru large scale studies that vegetarians, who lead a healthy lifestyle, are any less likely to have heart attacks, strokes or cancer?

The lack of hormones: and antibiotics found in meat can help w/overall health. Vegetarianism itself is not the only factor in prevention. Lifestyle is a huge factor. Diet and exercise essential. Attitude and good self-talk impact hormone levels. I'm a vegetarian. Peace and good health. Please get your B12 level checked. It can be low in vegetarians. Lots of studies to support all of the above.

They aren't: The last few really big studies showed no differences at all between vegetarians and omnivores with respect to disability or death from any of the major categories of disease. Becoming a vegetarian is a moral choice rather than one that promotes health, and I honor these people for this reason. They may also have other healthy habits; control for these and the benefits vanish. Your choice.