Backpacking food by calorie density: kcal per 100 g and per ounce

The yardstick: kcal per 100 g, or per ounce

Calorie density is the energy in a fixed weight of food: kcal per 100 g on most of the world’s labels, calories per ounce on American gear lists. REI, the US outdoor co-op, draws the line like this on its ultralight planning page: “at least 100 calories per ounce—125 calories or more per ounce is even better”.¹

Per 100 g: REI’s floor of 100 calories per ounce¹

353kcal

Per 100 g: REI’s better line of 125 per ounce¹

441kcal

How much of it you need depends on the day. REI puts a backpacking day at about 2,500 to 4,500 calories a person, which it reckons as about 0.7 to 1.1 kg (1½ to 2½ lb) of food;² its ultralight page aims for 0.7 to 0.9 kg (1½ to 2 lb) for the same calories.¹ REI’s own example of the spread: 16 km (10 miles) of hard walking with 1,200 m (4,000 ft) of climbing burns far more than a few flat miles.² France’s mountaineering federation puts a summer day in the hills at 4,000 kcal, for a walker of 65–70 kg carrying 5–8 kg.³

Thirty foods, densest first

Every figure in these tables comes from one database, USDA FoodData Central, and the ounce column is the same figure divided by 3.527. Keep to one database when you build your own list: the national tables can disagree by a quarter on the same food. Dried dates come out at 282 kcal per 100 g in the USDA’s figures and 356 in Germany’s.⁴⁵

Every one of them clears REI’s better line with room to spare, and none needs water or a stove. Oil is the extreme: a spoonful over dinner adds more energy for its weight than anything else on these pages.

Dry noodles sit exactly on the 125 line. Oats, couscous, instant rice and potato flakes land at 100–108 kcal per ounce: over REI’s floor, under its better line, and every one of them needs water before you can eat it.

Only the fried banana chips clear the line. REI’s own list of dense trail foods includes dried mango and apples;¹ on the USDA’s figures both fall short of its floor, at 90 and 98 kcal per ounce: the mango because it still holds 17 g of water in 100 g, the apple because fruit has almost no fat to lift the figure. That low-moisture apple, with 3 g of water in 100 g, is the nearest the USDA tables come to freeze-dried fruit.

Hard cheese, salami and jerky sit together at about 400. Fish in oil drops to half that, because 60% of it is water, and the figures are for the drained fish: the oil in the tin or pouch adds energy and weight on top.

Grams a day: the sum

Divide the day’s kcal by what 100 g of your food carries, and multiply by 100. Packaging comes on top of every figure here.

A worked day from the tables: 100 g of oats for breakfast, 125 g of couscous and a 100 g block of noodles for the two hot meals, 100 g each of peanut butter, cheddar, dark chocolate and dried mango, and 75 g of salami. That is 800 g (1.8 lb) and about 3,510 kcal, or 439 kcal per 100 g: just under REI’s better line.⁴ Five days of it come to 4 kg (8.8 lb) before packaging. Swap the mango for macadamias and the day crosses the line, at 489; swap the noodles for a tortilla and it falls to 421.

What density leaves out: water, a stove, heat

The number is a weight figure and nothing more. It says what a gram carries, not whether a week of it is a menu you’ll want to eat, and it says nothing about protein, salt or fibre; what drying does to those is in what freeze-drying does to nutrients.

Water. Every starch in the second table and the milk powder need water on top of their own weight, and a litre of water weighs a kilo. Count that water as part of the load, unless there’s a stream on the way that you can treat.

A stove, or time. Noodles and couscous soften in cold water; pasta takes hours. The times, and whose they are, are in cold soaking.

Heat. Both chocolates melt, and so does the trail mix that carries chips. In summer the last table is the one to rethink.

For a full trip plan with water stops and resupplies, food for a multi-day hike takes the same sum over three, five and seven days.

Our meals, by the same measure

A cooked meal with the water taken out carries about what the dry starches carry, and it needs its water back. Per 100 g as sold, Chicken & Rice carries 417 kcal, Porridge & Fruit 379 kcal, and a bag of Cherimoya 364 kcal, eaten dry as it comes.

Three of ours, on the same measure as the tables

Pouch	Energy per 100 g	Net weight	Energy	Water
Chicken & RiceLarge	417 kcal	200 g	834 kcal	370 ml
Porridge & Fruit	379 kcal	90 g	341 kcal	250 ml
Cherimoya	364 kcal	40 g	145 kcal	Eaten dry

Three of ours, on the same measure as the tables

• Chicken & RiceLarge

  Energy per 100 g

  417 kcal

  Net weight

  200 g

  Energy

  834 kcal

  Water

  370 ml

• Porridge & Fruit

  Energy per 100 g

  379 kcal

  Net weight

  90 g

  Energy

  341 kcal

  Water

  250 ml

• Cherimoya

  Energy per 100 g

  364 kcal

  Net weight

  40 g

  Energy

  145 kcal

  Water

  Eaten dry

What a pouch buys you is a whole cooked dish in one weight, not a higher number. On a day built from the tables above, a main and a breakfast take the place of the couscous, oats and noodles, and the nuts, cheese and chocolate stay in the snack bag where they lift the average. If you’d rather assemble the day yourself from shop food, a 24-hour ration from the supermarket does it with a shopping list.

From our range

One-Day Ration

A walking day in one box: 570 g dry, 2,321 kcal.

€42.90Hear from us before the shop opensSee the box