We notice that our kids (9 and 6) are impacted by the altitude in very different ways to us. Their appetites are much more suppresssed even for food they normally love, at least for the first 4-5 days. They also become much more sensitive to the cold - to the extent that this year we took chemical hand warmers with us (I.e. Carried them for 9 days despite only really mattering for 2hours).
The success of our trips with our kids (daughter summitted whitney at 6 and son at 7) is heavily dependent on nutrition and figuring out what they will eat. They don't have the same kind of glycogen and fat reserves that we have, and when at altitude and cold, they burn what little stores they have very rapidly. If we get the food right, they will happily hike 5-10 miles a day.
