I'm a sugar addict too. Pastries/cookies in the afternoon with coffee are my downfall!

For the last few years I've done a two week sugar detox just before the summer holidays. It's fabulous and amazing how quickly the weight falls off (I'm talking 3kgs in 2 weeks).

Granted, everything I eat I've prepared myself so I have absolute control over the ingredients. I think it would be difficult otherwise.

A great place to start would be to stop the known refined sugar sources: sweets,chocolate, cakes, breakfast cereals etc.. Also only drink water and or plain tea/coffee (remember this is only for two weeks - you can do it!! ;-)

And how long does it take for it to all go back on again?

Not to be a spoilsport but that's probably water weight - to lose 3kg of fat you'd probably have to wait quite a while longer.
Start eating sugar again and the water weight is back on.

IMO either radically change your eating habits for the long term or just reduce the foods you consider bad. What's the use of depriving yourself of sweets completely if you like them and don't overdo it?
My sweet tooth thankfully returned and when I wanted a Snickers bar a couple days ago I got it, but only after a 2km walk.

Drinking water only has had a wonderful effect though and is easy to keep up.

Not to be a spoilsport but a 2km walk will burn around 60kcal, while the snickers bar would give you back about three to four times that amount

I'm well aware of that, no worries. But it is 60cal less than if I hadn't gone for the walk.
Sweets aren't the devil in my book.

I experienced something very similar, and tried many things including looking at what I was eating. Nothing worked, except I did have some limited success when I followed the principles put forward by Michael Mosley in his "Fast Diet" in that the two fast days, I slept like a log and work up 'bright eyed and bushy tailed'. On the non fast days, I again had problems going to sleep and as a result woke up like a zombie.

BUT I have been able to change that round. And surprisingly, to me at least, it was when I committed to not being exposed to any digital media (no laptop, no tablet, no tv, etc) and hour before going to bed.

Instead of just going to bed and shutting my eyes and hoping to switch off, I have changed my habit in that I now always make sure that last thing I do before switching off the light, is reading a few pages from a good old fashioned book. Some nights I manage a chapter, other nights just a few pages. Important is that it is not business related, and that it is easy reading. Of course thoughts still come and go, but I do not give them unnecessary attention, instead I let them come and go, and make sure that the focus is on reading further, rather than pausing to think about what thought has just come up.

I can recommend smoothies for breakfast. You can add a lot of fruit and even some vegetables with natural yoghurt and milk. Adding something like oat powder will keep you full until lunch.

Lunch is easy IF you're happy to eat salad and make your own dressing. Balsamic vinegar is enough for me usually.

Maybe the biggest habit to break are your drinks. I drink mainly water throughout the day and a black coffee in the morning.

Also, there's a really good post I reference a lot called the anti diet. Here's a good excerpt:

In my opinion it is a good idea to reduce the sugar from your diet. I am trying to do it as well.
Eating less processed foods reduces "hidden" sugars. But I have noticed that there is just less processed food in Switzerland than the UK or US so that is a start. Although the quote above says the sugars in fruit and refined sugar are the same, you get much more from fruit than you get from refined sugar, like vitamins and fiber. So don't cut out fruit. Just be mindful of what you are eating.

Old thread, I know.

Bought some salami today (Citterio, Salami Milano), it doesn't taste right. Sugar??!! Yep, when I checked the ingredients, they mention sugar.
WTF!

I principally don't mind sugar (in my cake ... my ice-cream ...) but this salami is ruined.

I hear you. I too do not understand why savoury foods need sugar.

I ordered food with a rich meat sauce in a restaurant a week ago and it too had some syrup/sugar in the ingredients and I do not understand why.

Adding sugar is a quick cheat for over-salting.

We use pretty much exclusively Naturaplan Bio Fairtrade Rohrohrzucker ( raw cane sugar )