SWAG is a very important Diabetes term of endearment. It means Scientific Wild Ass Guess and it is used when there is no carb info available and you have to make your best guess.
So, when you take your T1 kiddo for some ice cream that was her promised reward for an outstanding swim meet performance, but then you realize that her BG is not optimal for ice cream…
…you take her anyway because a promise is a promise. And then she orders a milk shake, which is OK because a promise is a promise. So you SWAG the carbs at 100 g. (!) And she needs to give herself a shot because it’s a shit load of insulin and there’s not enough in the pump at the moment. Besides, a shot is more effective because she’s high already.
She does the shot without complaining and enjoys the hell out of her shake. But you still second-guess yourself and wonder if you should have given even more insulin.
Then a couple of hours later you ask her to check BG and BAM 💥