Re: Which backpack meals to use
Calorie wise, MRE's make sense as they have more food and a flameless heater. As you pointed out the down side is that they also produce far more trash and you use / have to carry more H2O.
If cost isnít an option I would go for First Strike Rations (FSR). They provide a mobile source of a variety of foods that are lightweight, calorically dense, familiar, and are easy to consume intermediate moisture foods. FSR reduces the weight and volume of one dayís subsistence by approximately 50% and provides an average of 2,900 calories per day. I think the majority of my Afghan patrols consisted of first strike rations and Gatorade shakes, well that and rip-its...lol!
Another option would be to supplement your MREís with dehydrated food . You could theoretically make the same amount of food weight last twice as long, your meals would taste better, you would have more options in terms of what you can make (a bag of flour can make you pasta, bread, tortillas etc. where in an MRE or backpacking meal, you get what is in the package.) and trash that you have to pack out is minimized, especially if you re-package your food before setting out on the trail.