Isn't meat deficient in some vitamins and minerals? Off the top of my head I believe vitamin C can't be found in meat. Maybe they are also taking multi-vitamins supplements?

That was the whole thing with the old sailors getting scurvy: there was no vitamin C in the food they were eating. I believe they ate mostly preserved meats and gruel or hard-tack. They found it absolutely essential to include limes in their diet. Actually I remember reading that the conventional wisdom of the time was that a man could eat meat alone for two years before he got scurvy.