Hi Jennylee. My first piece of advice is, everyone is different. So, don't read my experience, or anyone else's and feel like if yours is not exactly the same, then it's 'not working'.
Having said that, my experience was, I read the book, and I stopped eating sugar. That was a huge change for me, I used to eat TONS of the stuff, and I'd crave sweet snacks all day long. Driving past certain shops around here meant stopping for a cake or three ( literally ). I had been wondering why I could not control my desire to eat, working from home, I'd go to the kitchen every couple of hours at least, and if I was walking through, I'd stop in the sweets section.
Within a week, I felt I was full, all the time, and stopped wanting to snack. My portion size for meals dropped and a month on, I have lost 10 kg. I make a sugar free dessert on Sundays as it's the day we eat with my in laws, otherwise I have not felt any desire to eat sweets like I used to. In fact, yesterday we saw Avengers in Gold Class and I had a sip of my son's Sprite by accident and it just tasted odd to me.
So my major sign of progress, was appetite control. As for withdrawal, I'm not sure I had any, although my wife tells me I was grumpier than usual, I did not notice. So that's why I say, everyone is different, not least because of how big a change it is or isn't for you to go from xx amount of sugar to none. I suspect a lot of people who are looking for weight loss as a main attraction, probably were already dieting, so their overall calorie intake has perhaps not changed anywhere near as much as mine did. The thing is, if you lose a lot of weight or not, you are still better off without sugar.