Wow, you're really carrying a lot more calories than I do! Do you have data from previous trips on how much food you actually ate? I just came back from a trip where I packed 2000 calories/day, and I packed out quite a bit of my food. It's true that the JMT will be a big calorie-burning hike. I'm doing it solo, whereas my data from past hikes are mostly from hiking with my daughter, who is not a fast hiker. OTOH, I'm planning on feasting at the resupply points on food that I don't have to carry. Because of the uncertainty in comparing past hikes to this one, I'm thinking of taking maybe 2500-2800 cal/day.
To try to put this on an apples-to-apples basis:
What I usually actually eat on a trip is 2100 cal/day, which, divided by my body weight, is 15 cal/day/lb.
If I take 2650 cal/day on thr JMT, that's 19 cal/day/lb.
If you take 4300 cal/day, that's 27 cal/day/lb.
"For instance, we have cheese and salami for lunch some days, which isn't as calorie dense, but hummus and olive oil other days."
How many cal/g is hummus? My usual high-energy-density staples are nuts and cookies, which are about 5.5-6 cal/g. Yeah, love the cheese and salami!
The less energy dense foods I usually take are jerky, dried fruit, granola, and packaged seafood. On this trip, I'll probably only use the seafood as a resupply-day treat. The fruit and granola are probably helping me to avoid constipation, which I've had problems with in the past while backpacking. I hear a lot of through-hikers bring psyllium (e.g., Metamucil). I've never tried the stuff myself, but it seems like possibly an interesting option if one wants to avoid depending so heavily on fruit and granola for fiber.
BTW, that's a great photo with the frisbee! Do you play ultimate?