hello
yes, you can and I have had hypos whilst on metformin. If you don't eat enough for the exercise you are doing or in this case having the sourappletwostseps you will pass any nutrition out before it can be converted into energy. Your body needs help to fight illness, so eat lots, this is an exception to the normal good diet, when your well get back on it.
Please stay hydrated, get some salts/minerals in to help heal your gut and let those good bacteria get back to work.
my view.
I when ill just make sure I have enough food to fight the illness, I choose not to be perfect that day/days (not going back to a double helping of Singapore noodles!) but supplying the body with what it needs.