The answer to this is not straightforward:-)
We have adjusted to puberty by making meal times more flexible. We don’t eat a regular meal unless he is below 100, going down, with plenty of insulin.
Dinner is an easy adjustment because we aim for 6 or 6:30, and wait the peak out, sometimes till 9 if we need to. Breakfast is harder but he rarely has a peak right when waking up. But if he does we’ll replace his breakfast with something that has no carbs such as the turkey omelet sandwich I showed. For lunch, typically at school, if he has a peak he picks a sandwich at the cafeteria and takes it with him. He eats when he is down: it is part of his 504 plan that he may eat his lunch in class.
However, it does happen that he hits a really hard peak that we can’t get down fast enough for him. If he is really starving, we’ll have a meal with proteins, vegetables and nothing else: total carbs will be between 3 and 6 roughly. Vegetables typically have low GI, so we don’t see this type of meal show up on his BG track. It is easy for us to do because we have lots of veggies at every meal. It takes 7 minutes to steam broccoli in the microwave, for instance, then we add a bit of salt and olive oil, make a tomato and cucumber salad, a big chunk of protein (roast chicken is one of his faves), and we are done. A meal like this would likely be 5 carbs and 450 calories (we don’t skimp on the olive oil).
Then, once he is in range, we might add some carbs later, or not. When he misses a “real” meal, we typically give him a treat for desert later such as ice cream to make it up.
However, we never have a carb meal over 100. It is an understanding so we don’t need any enforcement – just the way we do things.