How Many Calories of Trail Food Do You Need for Hiking? Deciding the Amount and Number of Snacks
The sudden loss of strength on a hike that Japanese hikers call “shari-bate”, known in English as bonking or hitting the wall, is caused by running out of energy. Yet it is surprisingly hard to know how many calories of trail food, or how many pieces, to take. This article explains how to decide how much to eat while walking from your energy expenditure, guidelines for each share of that energy, example combinations of rice balls, yokan (sweet bean jelly bars), nuts and other snacks, how to split the amount across breaks, and how to eat so you do not bonk, all with concrete numbers.
Decide the amount of trail food by “what share of the energy you use to eat”
To decide how much trail food to take, you first need to know how much energy the course uses. Hiking energy expenditure can be estimated by multiplying the route constant, which expresses how hard a course is, by “body weight + pack weight” (see the route constant article for the formula). A person weighing 60 kg with a 7 kg pack on a course with a 5-hour course time, 10 km of distance and 1,000 m up and down uses about 1,510 kcal.
You do not, however, need to eat everything you use on the spot. The body has stores of carbohydrate and fat, and you also have the energy from breakfast. So decide “what share of the energy expenditure to eat while walking” and make that your trail food calorie target.
| Share eaten while walking | Target (intermediate course, about 1,510 kcal) | Suitable for |
|---|---|---|
| 30% | About 450 kcal | Shorter courses, days when you ate a big breakfast |
| 50% | About 760 kcal | The standard guideline for a day hike |
| 70% | About 1,060 kcal | Long courses, people who tire easily, cold days |
| 100% | About 1,510 kcal | Long outings where you want to replace as much as possible |
Trail food guidelines and example combinations by course
These are guidelines for a 60 kg person with a 7 kg pack eating 50% of their energy expenditure. The trail food is combined from rice balls (about 180 kcal each), mini yokan bars (about 170 kcal), 30 g bags of mixed nuts (about 180 kcal) and hard candies (about 20 kcal each).
| Course | Energy used | Target to eat (50%) | Example combination |
|---|---|---|---|
| Low-mountain hike (3 h) | About 820 kcal | About 410 kcal | 1 rice ball, 1 bag of nuts, 3 candies (420 kcal) |
| Intermediate day hike (5 h) | About 1,510 kcal | About 760 kcal | 2 rice balls, 1 yokan bar, 1 bag of nuts, 3 candies (770 kcal) |
| Long day hike (8 h) | About 2,420 kcal | About 1,210 kcal | 2 rice balls, 3 yokan bars, 2 bags of nuts, 2 candies (1,270 kcal) |
| Ascent only (ropeway down) | About 1,130 kcal | About 560 kcal | 1 rice ball, 1 yokan bar, 1 bag of nuts, 2 candies (570 kcal) |
On the same intermediate course, changing the share changes the amount like this: at 30% (about 450 kcal) it is 1 rice ball, 1 bag of nuts and 5 candies, and at 70% (about 1,060 kcal) it is 2 rice balls, 2 yokan bars, 2 bags of nuts and 1 candy. Calories vary by product, so recalculate using the labels on the packs you actually take.
Choosing trail food: mix fast-acting and long-lasting foods
| Trail food | Approximate calories | Characteristics |
|---|---|---|
| Rice ball (onigiri) | About 180 kcal each | Filling. Spoils easily in summer, so eat it early |
| Mini yokan (sweet bean jelly bar) | About 170 kcal per bar | Mostly carbohydrate, so it turns into energy quickly. Hard to squash |
| Mixed nuts (30 g) | About 180 kcal per bag | High in fat and calorie-dense. Acts slowly |
| Chocolate (25 g) | About 140 kcal | Convenient, but melts easily in summer |
| Energy gel | About 120 kcal each | Can be taken while walking. Take it with water |
| Nutrition bar | About 100 kcal per bar | Light and compact |
| Banana | About 90 kcal each | Bruises easily, so eat it in the first half of a day hike |
| Hard candy, dextrose tablets | About 20 kcal each | Can be eaten a little at a time. Handy for topping up the total |
- Carbohydrate-based foods such as yokan, gels and candy turn into energy quickly. Eat them when you start to feel tired
- Rice balls, nuts and bread act slowly and keep you full. Eat them at early breaks
- With only sweet things you get sick of them and stop eating. Mix in salty foods too (salted rice crackers, cheese and so on)
- Keep the food you will eat soon in a pocket you can reach without taking off your pack
Splitting the amount across breaks
Eating trail food a little at every break prevents running out of energy better than eating it all at once. Divide the calorie target by the number of breaks and you know how much to eat each time. For the intermediate course (5 hours of walking, an eating target of about 760 kcal and a drinking limit of 1,200 ml), the amounts for each break interval are as follows.
| Break interval | Number of breaks (including the end) | Food per break | Drink per break |
|---|---|---|---|
| Every 30 min | 10 | About 76 kcal | About 120 ml |
| Every 45 min | 7 | About 108 kcal | About 171 ml |
| Every 60 min | 5 | About 151 kcal | About 240 ml |
| Every 90 min | 4 | About 189 kcal | About 300 ml |
If you rest every 60 minutes, eat about one yokan bar or a little less than one rice ball each time; every 30 minutes, a few candies or a handful of nuts. How to decide how much to drink is explained in the water amount article.
FAQ
- How many calories of trail food do I need for a day hike?
- About 50% of your energy expenditure is a guideline. For a 60 kg person with a 7 kg pack on a 5-hour course with 1,000 m up and down, energy use is about 1,510 kcal, so trail food is about 760 kcal. That is roughly 2 rice balls, 1 yokan bar, 1 bag of nuts and 3 candies.
- Should I count lunch separately from trail food?
- Count it together as energy eaten while on the move. If you eat two rice balls on the summit, subtract them from the trail food target and spread the rest across your breaks.
- What is bonking (shari-bate)?
- It is running out of energy during a hike. The body runs short of carbohydrate and you suddenly lose strength, your legs will not move and you get chills. Eating a little at each break, before you get hungry, prevents it.
- Should I take extra trail food?
- Yes. In case you get back late, it is reassuring to carry one or two breaks' worth of light, long-lasting food such as candy or yokan as a reserve, separate from the calorie target.
- What should I watch out for with trail food in summer?
- Chocolate melts easily, and rice balls and bananas spoil easily. In summer, focus on heat-resistant foods such as yokan, nuts and gels, and add salt candies or salty snacks to replace the salt lost in sweat.
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