I'm taking risperidol and can't control my hunger/eating, is this a normal side effect?

Possible. Can have wt gain with resperdal but this is not s common side effect--watch carbs look 4 other possible causes.
Dispersal & Wt gain. I have had many patients gain excessive weight on risperdal. I try and switch the person to geodon, (ziprasidone) if possible, when that happens. I also use the medication metformin, which is indicated for diabetes. I find metformin helps with the weight gain which can help prevent diabetes. Other helpful medications are Naltrexone and topiramate. All need careful monitoring.
Yes. All second generation anti psychotics may cause this effect to a greater or lesser degree. Zonisamide was shown is a few small studies to block this effect but it may reduce efficacy of the treatment as well. Topamax (topiramate) and Naltrexone may also help.