Gujarathi food and low calorie cannot and should not be mentioned in the same sentence together. Gujarathi food is mainly of the vegetarian type and there are so many different snack options that are available to you. But I doubt that any of them will be low in calories. Snacks such as samoas and kachoris are a favourite. They are available extensively and since they are fried in oil, the calorie count is high. I suppose bhel puris and paani puris are the lowest calorie snacks that you can find. But if you are on a diet then don't go anywhere near them.