You do not have to completely avoid all high Glycemic index foods, but consume it in moderation. Low GI foods maintains your energy levels by preventing blood
sugar spikes. Include Olive oil, Coconut oil, walnuts , green leafy Vegetables, pear, apples etc.
Studies have shown that cutting down sugar and dairy products improves insulin sensitivity and balances hormone levels.
As far as gluten is considered it depends if you are having any intolerance to it. If it is not giving you any bloating or any other gastric problems whole grains should not be a problem