When I first began training, the choices in protein supplements were far more limited compared to today. One common source of protein back then was liver tablets and powders. Liver tablets were a staple of competitive bodybuilders in the 60s and 70s. Three-time Mr.Olympia winner, Frank Zane, would purchase liver tablets in boxes of 10,000 tablets, and ingest up to 50 tablets a day. Bodybuilding guru and elite trainer, Vince Gironda, who trained among others, the first Mr.Olympia winner, Larry Scott, advised those who sought greater muscle mass to ingest two liver tablets every waking hour. Vince's reasoning was that ingesting a small amount of protein would provide a consistent level of amino acids in the blood needed for growth. While food has always been the preferred primary source of protein, the bodybuilding magazines constantly implored the importance of consuming a very high protein diet if your goal was to increase muscular size and strength. The articles in the magazines often suggested that while many good high protein foods were available, such as meat, eggs, chicken, fish, and milk, it would be difficult to obtain enough protein from these sources alone to meet the increased needs for those who wanted to build muscle. That statement wasn't true, but there were some advantages to using a protein supplement. For example, if you were focused on losing excess body fat while maintaining muscle mass, a concentrated protein supplement could easily provide the extra protein needed without the excess calories that would be in food sources. Food sources of protein contain other nutrients besides protein, such as fat, which contains the most concentrated source of calories at 9 per gram, compared to the 4 calories contained in a gram of protein. The magazines back then, as is still true today, often featured current bodybuilding champions in the protein supplement advertisements, which implied that the massive muscles shown by these men resulted from using the advertised product. Those men did use the products, but their results were more likely from the combination of genetics, training, and in many cases, anabolic drug usage.
Besides liver tablets and meat organ-based products, the primary protein products years ago consisted of milk and egg proteins, soy-based products, and some questionable products made from who knows what. The two primary proteins existing in milk are casein (80%) and whey (20%). As processing methods increased in sophistication, it became possible to produce protein supplements based on either or both whey and casein, but in the past, the only thing available was whole milk proteins. The notion of ingesting protein supplements to promote muscle growth and fitness isn't a new concept. At the dawn of bodybuilding, athletes (they weren't called "bodybuilders" back then) favored a beef extract called "Bovril." Another popular protein of the early 20th century was a product called "Plasmon," which was a favorite of the archetypal bodybuilder himself, Eugene . . .