I think the message to this movie is great, and support anyone willing to consume less or better yet no animal products for health, the animals or the environment. Yet I find this somewhat unclear for viewers of what is healthy and even plant based. As it's promoted as healthier for athletes yet promoting gmo meat substitutes and cheeses, and prodomantly showing vegan food yet plant based (foundation or stepping stone) can still consume animal flesh and secretions yet there is no guide to what I can see considered as plant based whether it's one steak a day, one a year or none at all, I think this would be to individuals own perception. Which is the only diet I can see non specific. Planetarian diet is a good example of something that works with guidence whilst cutting down meat. Also although there is hard evidence out there as shown in other documentaries, what the health, forks over knives, fat sick & nearly dead. This movie lacks some, and I think the blood and erection test could have negative results of viewers as only done over 2 days, 4 people which could have eaten meat throughout the day.
However even tho to me it seemed off topic to physical health and athletic performance I really did like the fact they put in consideration for animals and environment towards the end, I guess it's a softer approach without using the word vegan which has a negative stereotype. Great results from viewers but could have been more specific and had some stronger evidence. A diet with guideline I see essential for some heavy meat eaters having not prepared many plant based/vegan meals, and hard evidence is critical for hard to crack carnists.