Don't remember a whole day's diet, but my son's favorite snack for several years was a huge scoop of peanut butter, about 1/3 of the jar. Grabbed the jar to figure the counts, and it is:
1520Kcal, 56gP, 40gC, 128gF
and that was on top of and eggs and cereal breakfast; full packed lunch- meat sandwich, fruit, cheese, vegetables, and dessert; and meat and two veg dinner.
In other words: a lot!