I found a meter essential.
I ws diagnosed diabetic, and used my meter to decide what foods spiked me, and which ones didn't. I didn't go HF, I just cut out all the carbs that spiked me, and found I was ok with others.
So I settled on lowGI/GL, portion controlled, lost over 4 stones, and got my BG back into the normal range.
Exercise also made a lot of difference to me.
I'm also just trying the Newcastle diet, to finish off the last stone, and see what happens to my BG.