hi Gussie Tomatoes are on the list of low glycemic vegetables but V8 juice is more carbs than you would get eating a fresh tomatoe. I guess it depends how much you drink and whether you get the low salt. V8 causes me to spike , in fact it is one of the things I reach for if I am going too low, So drink it and measure yourself and see what it does to your sugar level. Big can is 15 carbs that is more carbs than I have in a meal. This is all pretty intuitive after you get the hang of it. you have to watch what each food and each portion size does for you. each day is a whole new experience based on the amount of exercise you get and your strss level . if you are wanting something to crunch on in the car how about nuts or raw vegetables with ice water on the side. I venture to say none of us are drinking enough water.