On my diet (life style), one MRE contains most of the calories I am allowed in one day. I have noticed that the quality of the MREs have improved over the years. the convenience of being able to heat a meal without a fire is a real plus, if you have room enough to carry a few MREs. Sometimes I break down the MREs so they take up less space in my backpack.

Admittedly, I have not tried the heater pack in below freezing weather. It takes very little water to activate them, so I'll just have to try it or recheck the specs on them.