This is the first I heard of this.
Did he start that drinking habit at the same time as the McDonald's thing? If it was already an old habit by the time he started, wouldn't his health be in the gutter from the start of the burger diet?
No, he was a long-term alcoholic and that is why his final health report was so bad. Add in the additional calories he was drinking each day plus any DTs from a hard-core drinker trying to go straight for a few days while filming a movie and the results are pretty much exactly what we would have expected to see.
I think they did report his medical readings in the actual movie, might be worth going back to visit if they made an actual baseline reading and see what glimpse that gives for his initial health.
The doctor in the documentary tells him that his liver is damaged like an alcoholic's. He just let people assume it was from the food.