If you want nutrition, go with Ensure. If you have a source of water, you can get the dry mix. Seven servings pers cannister (about $1.25 per serving). 250 calories. It is low-cholesterol and low-sodium, has 24 essential vitamins. Gluten- and lactose-free.

You can also use it as part of recipes http://ensure.com/recipes/index.aspx

It's not high-calorie, and it's low in fat and fiber, not necessarily great in a survival situation, but that's not why it was created. Ensure and granola bars, a complete diet?

Sue