In the last 2 weeks i have had problems like this and its not 3 or 4 hrs after eating, its more like an hour or two. I go all weak, irritable and have to eat something. I havnt eaten sugar for well over a year and i use stevia. I make my own biscuits and cakes with stevia. The strange thing is, i never got this with amalgam in my mouth, i have had mine removed now for nearly 5 mths.