Mark Bitmann is an author, food journalist, and long time columnist for the New York Times. He wrote the book, VB6 which is about being a vegan all day long until 6pm, then eating what you want.
So while we have some similarities in the fact that we are both part-time vegan plans, we have a key difference.
Bitmann’s plan encourages eating vegan for 2/3 of the day - for breakfast and lunch. With Tiny and Full, it’s only for 1/3 of the day — just breakfast. This is because of the nutrients, especially B12, that you get from animal-based food throughout the day to help maintain your energy levels. If you do not get enough B12 in your diet, you can become B12 deficient which depletes you of energy, causes mood swings, and more. I believe that by still emphasizing plant-based foods all day long but having those animal foods for lunch and dinner, you can get all of the health benefits, maintain energy levels, and eat a well rounded diet.