As a child in grade school back in the 1940's, I recall receiving accasional health directives from the school nurse, telling me that eating red meats, dairy products, eggs etc., etc., would make me grow up healthy. With todays views on diets. I wonder if the doctors back then were building future business for themselves, or were they ignorant of the facts and spouting out what they thought was reliable knowledge on the topic back then?
I think back then it was well intentioned ignorance. I can't say the same about today's medical industry. I think that the industry will see much more business resulting from today's prescription-for-everything approach to medicine. Most prescription drugs have side effects, some completely unknown, that will make you sick later. My favorite is the TV ad for a medication to treat toenail fungus, which comes with a disclaimer that treating your fungus may cause liver damage or death.
I am guessing you could probably kill the toe fungus by soaking in salt water, but even if you can't your probably better off keeping the fungus and your liver.
I think much of it was ignorance, but at the same time today isn't much different. There's plenty of things far worse than what your doctors were pushing. Hospital food alone is designed to keep the beds full and doctors nowadays talk as if diet and health are unrelated. They have a pill for everything and preach against anything natural
If hospital food is designed to keep people in the hospital they must be really incompetent. Even I could tell them all it takes is a little e.coli in each dish and their patients (who can eat nothing else) will remain there. Nevertheless, people are discharged from hospitals every day as fit to go home.
I think they were telling you what they thought was good for you. I once read a 'health' booklet from the 1850's which only gave this nutritional advice: "A person should eat no more than four pounds of food a day, with only one pound being meat." Things used to be so much simpler.