I would say between 4-8mmol. I zap the sensor (I use a Libre freestyle) when I first start to eat and then set the reader to remind me 1 hr and 2 hrs after noshing. I use MyFitnessPal to keep a food, water and notes diary of everything, and also handy to track exercise. That way you can build up a picture of what causes your BG to rise, what effect eating other foods/changing your diet has and eventually you will get a feel for it.