As in most documentaries, the filmmaker follows a few individuals to demonstrate the power of this diet in terms of weight loss and improved health. I remember one family man because with the help of a progressive-minded physician, he was able to come off and stay off his medications for diabetes and conditions tied to heart disease (e.g., hypertension and high cholesterol), which is pretty incredible.
The most famous person on the diet advocated by Drs. Essylstyn, Jr. and Campbell isn't in the movie, but you can see him speak briefly on why he adopted a plant-based diet and how he lost weight on that diet. Amazingly, he claims he's been on the diet for many months - which underscores that a plant-based diet isn't about crash dieting but rather part of one's lifestyle.