My daughter had these almost nightly from when she very young til about 4 and my son occassionally had them @ 2 yrs. old. I learned from a friend that she stopped her kids from having ANY sugar after 4/5 pm and they stopped completely for her kids. I tried it and was amazed that it worked for my kids too. I suggested to another friend whose kids had ice cream every night after dinner. She stopped and they lessened greatly in her situation. My daughter will still occassionally have them and there was no sugar involved...most recently she woke up every 1/2 - 1 from 9:30pm til 4 am...that was the worst. I took her to the dr. the next day thinking she was coming down with something...nothing...so maybe she was overtired then? She is 7 now.
I hope the no sugar at night is the answer for you too!