Absolutely. I also don't know the exact physical figures but I know digesting food alone warms a person up.

Before my last physical exam the doctor made me fast for the entire day before. My last food was Sat. evening & by mid afternoon on Sunday I felt chilled. Without the calories coming in it had a an effect on me & I was sitting in my house watching football. How much worse would it have been if I had been hanging out in a snow cave?

Shelter/Water/Signaling come first for sure, but hunting & foraging should be part of our plan.