Failed OGTT.

I recently went for my OGTT, found out the result was very high and been told to have a healthy balance diet. I'm really clueless as to what I'm suppose to look out for, Yes the obvious is sugar intake but honesty, I've cut down alot on my sugar way before pregnancy so I still find it impossible that the result were high. Anyone can help enlighten me? Like What to eat for breakfast, lunch dinner? Oh not to forget, I don't take any supplements. Folic acid makes me nausea.