Humans have always eaten meat. your body requires it. It has all the proteins and vitamins you need to stay healthy, when combined properly with a balanced diet of at least 2 vegetables, something from fruit or a fruit itself, and a staple food, like rice, pasta, or bread. The idea is NOT to make yourself deficient on one thing or another, and eat them in a balanced daily intake sort of way. You should also do regular exercise. OF COURSE you should spend some time in the sun. Anyone with an open mind knows that vitamin D comes from the sun. If you keep anything out of the sun for too long, it will get sick, unless it is a mushroom. When I was a kid, back in the 70's, we were taught about "Canada's food rules", which were all about keeping a balanced diet. New fads have always arisen, with silly diet or health gurus trying to sell their idiotic ideas, at the expense of the gullible. Trust in balances. Too much or too little of anything can be detrimental to your health.