I have no special dietary needs... Just a sweet tooth and a love for jerky. I'm a big guy (I'll be dropping 60+ pounds to get to Philmont-allowed weight), but even down in the 225 pound range, I need to pull about 5000 calories a day for strenuous hiking. Philfood is good for 3500 or so, from what I hear. I could probably stand to run a calorie deficit for ten days, but I'd rather not if I don't have to.
I don't mind carrying the extra weight of some snacks. Right now I'm used to carrying 340+ "ground up" pounds ("skin out" + "skin in"). Between what I've learned on these forums, some wise gear purchases, and the diet, I'm looking to be at 250 pounds from the ground up. The more I lose from the me-weight and the base-weight, the more wiggle/luxury/snack room I have.
I will give the Philmont folks a shout to see if they have any particular restrictions.