Wife is Pre-diabetic.

Wife is Prediabetic according to our doctor. Her father and her uncle both have type 1 diabetes. The doctor said she has to loose 10 pounds in 3 months to fight getting type 2 diabetes. Shes overweight for sure but not fat by any means shes 5'11 and 170lbs.

Its a good excuse for us to start dieting anyway (I'm 370lbs and a bad influence on her i'm sure)

My questions are what kind of diets work or are there reputable resources for this. I keep getting articles that seem to be hating on everything not just things that spike sugars. Cut out GMOs and stuff like that. Id like something with a little more science backing up the claims in the article then just someones opinion.

Also what kind of exercise is best to help this ?

Thanks all.