The snacks keep me from getting hungry. I am losing weight (today being an exceptionally bad day to pick as an example) eating three snacks. I do understand other plans tell you to let your body's metabolism move up and down in a rhythm. Others tell you to eat two meals a day, others say six small meals.... the big secret is the may all be correct. You have to do what is right for you, with medical guidance if appropriate.
All I can say is this is working for me. But speaking only for myself as a diabetic whose blood sugar gets LOW at times on SBD, I cannot imagine being able to do SBD long with no snacks to manage things.
Why not give SBD a try the way it's drawn up? Make sure you get plenty of exercise -- that will help with the fat burning! And exercise is an undercommented-upon but essential part of SBD.
As for the transition, some folks pick one food for a week, some pick two (a grain and a fruit for instance) and have one one day, the other the next. Then the next week either try something different as a replacement or add something to the rotation. It's a matter of preference. Just watch portions and monitor how your body feels with each thing you try.
"Foolish boy. Your powers are no match for the dark chocolate side of the force." - Darth Cadbury