There are two camps about runner foods. The Keto crowd, they tend to eat nuts. The rest, eat high carbs foods, think bananas, oats, gummies. Both of them nee

There are two camps about runner foods. The Keto crowd, they tend to eat nuts. The rest, eat high carbs foods, think bananas, oats, gummies. Both of them need a huge amount of fuel. A marathon burns about 2,500 calories from exercise alone, for the average person their TDEE is about 2000. So 4,500 calories a day to break even, without taking into account the heat. At 4.5K calories, that's 94.5K calories for 3 weeks. The average granola bar is 132 calories, let's pretend he chose a nutrient dense one for 150. That's 630 granola bars. It's not impossible, but not ideal. You also need to deal with mineral deficiencies for 3 weeks worth of travel. Sodium and Potassium are both needed for intense exercise, which two marathons a day definitely counts. Like I said, he has as crazy idea, but he is not in touch with reality. Dehydrated meat would probably be good....now I wonder how he goes to the bathroom.