A fleeting comment in another forum got me to thinking. When I did the Ornish Diet (super low fat) I was losing hair at the fastest rate I ever encountered. The FDA endorsed low fat-high carbs after a very biased interpretation of the famous Framingham Heart Study. The doctors announced what they wanted to find, ignoring the true results. The FDA presented the famous Food Pyramid demonizing fat, and Americans went on the low fat craze. Obesity make a huge leap, and has not yet returned to normal. I originally dismissed Melvin's question, but now I am thinking that the sham put forth by the FDA may have an effect on hair loss. We are omnivores and they tried to turn us into herbavores. A good study would be Vegans to see their hair loss patterns. As with all do gooders they create their own reality to fit their agenda, sadly this time it adversely effected millions of Americans.
https://www.today.com/style/foods-eat-avoid-healthy-shiny-hair-t5811