People who come to eating this way with concerns about their weight, were probably dieting to start with. There is a whole slew of reasons to stop eating sugar, regardless of your weight. You can eat sugar free and still eat more than you need ( although your appetite control should kick in and help with this, it's worth pointing out, you can't cut sugar, eat huge meals, and lose weight ).
I lost 10 kg in the first month and 4 since then ( in two months now ), despite being less than perfect the last 2 weeks or so. But, I had a VERY high sugar diet beforehand. I would say the best advice is, eat no sugar because it's good for you, and try to make good choices above that if you want to lose weight, but also accept that regardless of what you weigh, you will be healthier without sugar.