I've been experimenting on doing a calorie deficit while backpacking.
So far the results are mixed.
I seem to start off strong in the morning and then tend to fade in the afternoon.
It seems that I tend to eat most of my food at the beginning of the day, and then have a 4-7 hour period where I don't eat.
That later period is where I get tired.
There are a couple options here:
1. I just get tired normally (it's a lot of energy expenditure) and there isn't much I can do about it.
2. I am tired because I've depleted muscle glycogen and have low blood sugar.
it also might be a combination of the two (factoring in single cause fallacy).
So what I was thinking of doing was bumping up my calories and consuming something like 200 calories per hour starting from a couple hours after breakfast and a couple hours before dinner.
Say have 800 calories for breakfast. Then another 800 for dinner. and then 7x 200 calorie snacks in between. One issue is that for longer trips this will be a LOT of room in my bag. 7 granola bars is kind of a lot of food.
My theory is that going TOO lean on food could be a false economy. If I cut food TOO low I'm going to be lethargic and slow which counterproductive with the weight savings I have for less food.

