We have always struggled for lunch choices while backpacking but have found that the Jif To Go cups work well since it's a dense source of calories, protein and fat. I usually have two of the 1.5 oz cups which I just eat with a spork or dip out with piece of dark chocolate. Of course you need to have plenty of water handy. This year we are opting for YumButters. These are healthier with natural peanut butter, plus chia and hemp seeds and some coconut palm sugar. These are 7 ounce containers which will sometimes last us for 2 days but will be fully consumed on bigger mileage days.
Heff