Why would you want low fat while you're backpacking? Fat got a bad reputation at some point, but it's essential, and public opinion is slowly starting to catch up with the science. Fat is not evil, especially consumed in healthy natural forms (nuts, seeds, coconut, avocados, ...). Plus, it's already a huge challenge to pack enough calories into a very small volume and low overall weight, and packing foods high in healthy fats helps with this.