As part of my recent nutrition course (Nutrition for Health Promotion and Disease Prevention) we did a module on Diabetes and we were introduced to the Exchange List system where foods are grouped according to a category eg Proteins, Starches, Nonstarchy vegetables, Fats etc. Similar foods in each group have the same amount of carbohydrates, protein, fat and calories. Each food item is listed with its quantity.

I am not a diabetic but I do find these lists easy to follow and a quick reference guide and it makes meal planning much easier

The website I use is the Mayo Clinic

http://www.mayoclinic.com/health/diabetes-diet/DA00077

Hope this may be useful to you