So I found this website that lists specific heat capacities for various foods, and while it doesn’t list “snacks”, dry foods values seem to range from 0.3 to 1 cal•g-1•K-1 = 0.0003 to 0.001 Cal•g-1•K-1. Assuming no phase change (i.e., melting) and otherwise temperature-invariant heat capacity, the energy required for heating a 100 g snack from freezer temps (-18 °C) to body temp (37 °C) is 1.65 to 5.5 Cal. More realistically, we can compare to eating an ambient-temp (20 °C) snack; that difference is only 1.1 to 3.8 Cal… in either case, the difference is negligible, generally < 1% of the calorie count of the snack itself.
So I found this website that lists specific heat capacities for various foods, and while it doesn’t list “snacks”, dry foods values seem to range from 0.3 to 1 cal•g-1•K-1 = 0.0003 to 0.001 Cal•g-1•K-1. Assuming no phase change (i.e., melting) and otherwise temperature-invariant heat capacity, the energy required for heating a 100 g snack from freezer temps (-18 °C) to body temp (37 °C) is 1.65 to 5.5 Cal. More realistically, we can compare to eating an ambient-temp (20 °C) snack; that difference is only 1.1 to 3.8 Cal… in either case, the difference is negligible, generally < 1% of the calorie count of the snack itself.