Hiking Nutrition: Trail Food, Backpacking Calories, Electrolytes and Water Treatment

This article contains affiliate links: if you buy through them we may earn a commission, at no extra cost to you. Learn more.

Day three of a backpacking trip, and food has become the main topic of conversation. Someone is rationing peanut butter M&Ms; someone else dreams aloud about pizza. At the stream, the filter squeaks as a friend squeezes out tomorrow’s water. Food and water are the fuel of every hike, from a family day out to a thru-hike of the Pacific Crest Trail, and they’re also where hikers make the most fixable mistakes: too little food, plain water without salt, and untreated water. This page covers hiking nutrition for day hikes and backpacking, electrolytes, water treatment, and the few supplements worth a look.

General information for healthy adults, not medical or dietary advice. If you have diabetes, a heart or kidney condition, high blood pressure or a special diet, follow your doctor’s or a registered dietitian’s plan. Back to the hiking hub.

How much energy hiking takes

More than most people pack. Grand Canyon rangers tell hikers they need to eat about twice as much as they normally would to meet their energy needs, and compare each hour of canyon hiking to shoveling wet sand. On long trips the gap grows: a case study of a 55-year-old Pacific Crest Trail hiker measured total energy expenditure of about 5,700 kcal a day against an intake of about 4,100 kcal over the 2,340-mile (3,767 km) hike. He lost 9% of his body weight, nearly half his body fat and 8.6% of his spine bone density, signs of the low energy availability that sports medicine calls REDs (Relative Energy Deficiency in Sport). A second case study, of a 62-year-old woman on the same trail, found she ate about 1,300 kcal a day against an estimated 2,300 kcal burned, with losses in body composition and performance. The researchers’ advice: eat more, or shorten daily distances.

Carbs, protein and fat on the trail

The joint position statement on sports nutrition from the American College of Sports Medicine (ACSM), the Academy of Nutrition and Dietetics and Dietitians of Canada gives daily carbohydrate needs that rise with training load: about 5–7 g per kg of body weight on moderate days (about an hour of exercise) and 6–10 g/kg on days of 1–3 hours, up to 8–12 g/kg for 4–5 hours a day of hard exercise. Hiking is usually gentler than the athletes those numbers were written for, but long trail days with a pack sit near the top of that range. Protein: ACSM suggests 1.2–2.0 g/kg a day for athletes, spread over meals. Fat is the backpacker’s friend because it packs more than twice the calories per gram of carbohydrate or protein, which is why nut butters, nuts, cheese and olive oil show up in so many food bags.

What to pack: day hikes and backpacking

Meal	Day hike	Backpacking
Breakfast	Oatmeal, eggs, toast, coffee before you leave	Instant oats with nuts and powdered milk, granola, coffee
Every hour	Trail mix, bars, dried fruit, pretzels, crackers	Same, plus nut butter packets, jerky, cheese, chocolate
Lunch	Sandwich or wrap, fruit, salty chips	Tortillas with tuna or salmon packets, hard cheese, salami
Dinner	A real meal at home	Freeze-dried meals, couscous, instant mashed potatoes, ramen with olive oil

The National Park Service suggests trail mix, nuts and granola bars to keep your energy up; Grand Canyon rangers favor salty snacks such as pretzels, chips and cheese crackers. Store food away from wildlife: in bear country, follow the area’s rules for canisters or hangs, because, as the NPS says, a bear that gets human food becomes a problem for everyone. How much to eat and drink each hour on the trail is on Hike Day.

Electrolytes: salt matters

Sweat carries sodium, and hikers in the heat can lose one to two liters of sweat an hour. Grand Canyon rangers recommend salty snacks plus water or a sports drink on any hike longer than 30 minutes, and warn about hyponatremia: low blood sodium from drinking a lot of plain water while losing salt, with fatigue, nausea, vomiting and confusion that can look like heat exhaustion. The National Athletic Trainers’ Association (NATA) advises drinking to thirst when you don’t know your sweat rate and adding sodium for heavy, salty sweaters. An electrolyte tablet or drink mix is an easy way to carry it; compare options in our electrolyte powder guide and LMNT vs Liquid I.V.

Water treatment: a short but important note

Clear mountain water can still carry germs. The CDC’s guidance for hikers and campers:

• Boiling is the most reliable single method: a rolling boil for 1 minute, or 3 minutes above 6,500 feet.
• Filters with an absolute pore size of 1 micron or smaller remove parasites; 0.3 micron or smaller remove bacteria and parasites, but not viruses.
• Chemical tablets: chlorine and iodine kill bacteria and viruses but don’t work well against parasites; chlorine dioxide works better against Giardia and Cryptosporidium.
• Best combination: filter first, then disinfect with a chemical or UV light.

Hand hygiene matters too. In 2022, a norovirus outbreak sickened at least 27 confirmed hikers on the Pacific Crest Trail in Washington; the CDC found human fecal contamination on surfaces in a cabin and pit toilets, and noted that alcohol hand sanitizer, the hiker’s standard, doesn’t work well against norovirus. Wash with soap and water where you can, and don’t share snack bags. A popular filter is the Sawyer Squeeze, rated at 0.1 micron by the maker, which removes bacteria and protozoa; add a chemical treatment where viruses are a concern.

Supplements: what’s worth considering

Food comes first. The IOC’s consensus statement on dietary supplements says sports foods (drinks, bars, gels, electrolytes, protein) can be a practical way to meet needs, and that only a few supplements have good evidence for performance. For hikers, the useful ones are mostly practical:

Product	Per serving (label)	Third-party testing	About per serving
Nuun Sport	300 mg sodium, 1 g sugar	Informed Choice (maker)	$0.75
Skratch Labs Hydration	400 mg sodium, about 20 g carbs	NSF Certified for Sport (maker; not found in NSF’s database when we checked)	$1.20
Thorne Whey Protein Isolate	21 g protein	NSF Certified for Sport	$2.17
Klean Multivitamin	Includes 1,000 IU vitamin D3	NSF Certified for Sport	$1.53

• Electrolytes: useful in heat and on long days; follow the label.
• Protein powder: a light way to add protein on a long trip or after big training days. Compare in our protein powder guide.
• A multivitamin: some thru-hikers take one when fresh food is scarce for weeks; it doesn’t replace food. See our multivitamin guide.
• Caffeine: one of the few supplements with strong evidence; many hikers just use coffee or caffeinated gels. It isn’t for everyone (sensitivity, heart conditions, pregnancy), and the American Academy of Pediatrics says energy drinks have no place in kids’ diets.

Supplements aren’t approved for safety or effectiveness before sale, and some have been found contaminated with undeclared substances. Choose products tested by a third party such as NSF Certified for Sport or Informed Sport/Informed Choice; those programs lower the risk but don’t prove a product works. Never exceed the label dose, and talk to your doctor or a registered dietitian before adding supplements, especially if you take medicines. Altitude medicines are prescription only and a matter for your doctor (see hiking injuries). For refueling after the hike, see hiking recovery; for team athletes, compare soccer nutrition.

Hiking nutrition: FAQs

How many calories do you burn backpacking?

It varies with body size, pack weight, terrain and distance, so there’s no single number. On the long end, a Pacific Crest Trail case study measured about 5,700 kcal a day; Grand Canyon rangers tell day hikers to eat about twice their normal intake.

What are the best snacks for hiking?

Foods with carbohydrate, some salt and enough calories for their weight: trail mix, nuts and nut butter, bars, dried fruit, pretzels, crackers, cheese and jerky. Eat a little every hour rather than waiting until you’re hungry.

Do I need electrolytes when hiking?

On long or hot hikes, yes, from food or drink. Grand Canyon rangers recommend salty snacks with water or a sports drink on any hike over 30 minutes, which also lowers the risk of hyponatremia from drinking plain water alone.

Is it safe to drink from mountain streams?

Not without treatment. The CDC says boil water (1 minute, 3 above 6,500 feet), or filter it and then disinfect it. A filter alone doesn’t remove viruses, and chlorine or iodine alone doesn’t reliably kill parasites like Cryptosporidium.

Does hand sanitizer stop stomach bugs on the trail?

Not reliably. In the 2022 Pacific Crest Trail norovirus outbreak, the CDC noted that alcohol-based sanitizers aren’t effective against norovirus. Wash with soap and water when you can.