I am a flatlander from tx and EVERY time I get above 10,000 feet I get a splitting headache for the first 24 hours sometimes so bad they initiate vomiting and then after that 24 hrs I am acclimated and I am good to go. However, caloric intake is a hard thing to answer. I dont have much of an appetite up there so I literally have to force feed myself, especially in the morning and during the day. Its great for weight loss though, just returned from a scouting trip and lost 5% of my body weight in 5 days. So for me, I eat as much as I can, which isnt much and nowhere close to the caloric intake I take in while at home. I echo the others - water is the key.