Life expectancy statistics for nutrionists, life style gurus and medical doctors?

Depends on what they advocate. I don't see those advocating hydrolized Spirulina or sun and air as a prime source of nutrition with no requirement of further food intake live very long. But Germany's Dr Max Otto Bruker who advocated a diet of "live" wholefoods and no animal proteins has lived to the ripe old age of 92 even though he only discovered the facts that became his dogma in his fifties (mind you, over-weight, cigar-smoking, roast-devouring Winston Churchill managed 93...).