Perhaps for some folks the most challenging part is the first 3 days or so until your body goes into ketosis. That part never bothered me at all. I think maybe way back in in the very, very beginning when I had never tried ketosis before it did feel a little weird because I was used to stuffing myself everyday. Fried chicken, hamburgers, milkshakes, pizza (all you can eat at Shakeys!) snacks galore, string cheese, gummi bears, sour worms, tacos, burritos(BIG BURRITOS) hostess cupcakes, pepsi, more pizza, microwave popcorn, big submarine sandwiches, pies, pastry. I was like a food vacuum! To go cold turkey from that to ketosis could be quite a leap. I'm used to it now and it's simple to start and those first 3 days never give me any trouble. Just tons of water to fill you up instead of pizza and 3 days later you enter ketosis. Like I said before, speaking only for myself, once in ketosis I have ZERO desire for any food.