The foods with a high glycaemic load are often the ones which are most refined and can be identified by colour: very white! Anything with finely ground white flour is not good and if it is mixed with sugar - OH NO, NO, NO!! There are a few cookbooks aimed at this market which are excellent reading as well as having nice recipes and when you understand the concept it makes it easier to understand what sort of foods are best for you. The idea is to aim for food that takes a longer time to digest so you feel fuller for longer. You also need some fat but not too much as that is also bad for diabetes but fat also fills you for longer.
Many of the diet foods have low fat because fat is the most calorie dense part of our diet and that reduces the calorie count - but it isn't all about calories. The diet food with low fat has extra carbs to replace it and when you read the ingredients list it is truly horrifying (well, it is to me!). And it is all in a form that is absorbed at high speed from your stomach, you get a spike of blood sugar, your body shovels out the insulin to combat it and the result is the blood sugar level falls very rapidly and overshoots to a level that is too low. Then that makes you feel shaky and hungry so you grab a bun or a snack to make you feel better but all that does is start this circle going again. Keeping carbs down and using veggies and protein to fill you up is much better for you - and as a side-effect it will also help reduce any muscle wasting due to the pred.
Enjoy finding info and recipes on the internet