I just wiki him he was 50 when he died mate.
I found this below very fascinating basically and correct in my view.
Diet has always been as important, if not more, as weight-training for bodybuilders. However, in his book Heavy Duty Nutrition, Mentzer demonstrated that nutrition for athletes did not need to be nearly as extreme as the bodybuilding industry would lead one to believe. His recommended diets were well balanced, and he espoused eating from all four food groups, totaling four servings each of high-quality grains and fruits, and two each of dairy and protein daily, all year-round.
Mentzer believed that carbohydrates should make up the bulk of the caloric intake, 50–60%, rather than protein as others preferred. Mentzer's reasoning was simple: to build 10 pounds of muscle in a year, a total of 6000 extra calories needed to be ingested throughout the year, because one pound of muscle contains 600 calories. That averages 16 extra calories per day, and only four of them needed to be from protein—because muscle is 22% protein, about one quarter.
I always thought myself for the longest time through personal experience "carbs" is what makes muscles grow not just amino acids and protein as much as people wanna believe, my reasoning is that muscles mainly glycogen and water and indirect affects of carbs make you stronger etc.
Always when I eat high carbs my muscles are nice and full and I grow quickly.
Off course the problem is not just about adding muscle but keeping fat away and carbs make me fat easily too especially cos I am carb sentitive so always have to trade size for conditioning or conditioning for size and getting balance right is hard.
Now I am of the opinion that I will just let the drugs to the work, only true way really.
Metformin to counter fat storage, thyroids for fat loss, AA's for size/conditioning...etc.
I don't really want to live beyond 60 and even that is too much for me.
Although Mentzer took some liberties with his reasoning, this idea is generally correct and is something that the majority of people who train for muscle growth don't realise:
Calories are the most important dietary factor in growing new muscle tissue, not protein. The total amount of protein needed to build a pound of new muscle tissue is FAR LESS than people believe. However it takes several thousand SURPLUS calories to fuel the metabolic processes involved in the formation of new skeletal muscle.
What typically happens with most bodybuilders is they dump excess protein into the system (e.g. several hundred grams per day) and eat too few carbs and especially too few fats. The body converts this excess protein into glucose and essentially uses it for energy. The problem with this approach is that this is an extremely inefficient way for the body to create energy. Carbs and fats are much better and more accessible forms of energy.
The most logical and efficient approach is to consume protein carbs AND fat. Unfortunately people are either high fat/zero carb or high carb/zero fat, when really moderate amounts of the two nutrients, along with protein, is the best way for lean muscle growth.