I've eaten Heater Meals for years. They're a good thing to have around when you can't cook a meal for whatever reasons. I'm 61, and I find the portions too small when I'm active (camping, for example).

I've got a list of meals that require little or no cooking at
http://www.cieux.com/bm/quickMeals.html

My issue with many of them (including military MREs) is that each portion includes just about a whole day's worth of sodium, fat, and calories - and Heater Meals do not. A day's worth is fine for active young people, but I just don't want that much since I eat three meals a day.

The companies I list offer a wide range of foods, including kosher, gluten-free, vegan, and so on.