Fuel for Thin Air: Eating and Drinking Well at Altitude

At altitude, food and water stop being background comforts and become part of how well you feel. The short version: drink considerably more water than you think you need, lean your meals toward carbohydrates, eat little and often even when appetite fades, and be cautious with alcohol in the first days. Those four habits quietly carry a great deal of an Andean or Himalayan journey.

The reasons behind them are worth knowing, because once the logic is clear the habits stop feeling like rules and start feeling obvious. Here is what the thin, dry air does to appetite, thirst and digestion — and how to eat and drink your way through it.

Why hydration matters more up high

You lose water faster at altitude through two quiet channels. The air is very dry, so every breath carries moisture away, and you breathe faster and deeper than at sea level — so the loss compounds. The cold also blunts the sensation of thirst, meaning you can be meaningfully dehydrated without feeling it.

This matters because dehydration shares its early symptoms with mild altitude sickness — headache, fatigue, light-headedness — and can both mimic it and make it worse. Drink steadily through the day rather than in occasional gulps. A practical sign you are getting it roughly right is pale, plentiful urine; dark urine at altitude is a prompt to drink more.

How much, and what, to drink

There is no single magic number, and you can overdo it — forcing litres far beyond thirst is unnecessary and occasionally harmful. As a working guide, many travellers aim for somewhere around three to four litres of fluid across a high-altitude day, more on an active one, adjusting to the pale-urine test rather than a stopwatch.

Plain water is the foundation, but warm drinks earn their place at altitude: they hydrate, they comfort, and they help against the cold. Andean travellers lean on coca tea and herbal infusions; soups and broths count too, and they replace some of the salt lost through harder breathing. Sugary fizzy drinks and a great deal of strong coffee are poorer choices — caffeine in moderation is fine, but it is mildly dehydrating in quantity.

Why your body wants carbohydrates

There is real physiology behind the Andean plate of potatoes, rice, quinoa and bread. Carbohydrate is the fuel the body burns most oxygen-efficiently — it yields more energy per unit of oxygen than fat does — which is precisely the trade you want when oxygen is the scarce resource. Studies of high-altitude diet have long pointed travellers and climbers toward carbohydrate-rich eating.

So favour starchy, carbohydrate-leaning meals at altitude, and keep easy snacks close: dried fruit, biscuits, cereal bars, nuts. You need not abandon protein or fat, simply tilt the balance. The traditional cooking of the high Andes, built on tubers and grains, happens to be very well suited to the altitude it is eaten at.

The vanishing appetite, and how to handle it

One of altitude’s reliable surprises is that hunger fades. Many travellers find their appetite noticeably suppressed in the first days high, and meals can feel like a chore — yet this is exactly when the body needs steady fuel to power acclimatisation.

The answer is to eat little and often rather than confront large plates. Graze on snacks through the day, choose foods you genuinely find easy and appealing, and do not be discouraged if you eat less than usual at first — appetite generally returns within a few days as you adjust. Mild nausea is common too; gentle, bland, carbohydrate-based food usually sits best. Persistent vomiting, by contrast, is a symptom to mention to your guide.

Coca, alcohol and the Andean table

Coca leaf — brewed as tea or chewed — is woven into Andean highland life and is offered everywhere from Cusco to the altiplano. It is a gentle, traditional comfort that many travellers find genuinely settling for a mild headache or queasy stomach; it is not a treatment for altitude sickness and not a substitute for acclimatising, but as a warm, mild infusion it is part of the pleasure of the high Andes. (One practical note: it can produce a positive result on some drug tests for a period afterwards.)

Alcohol asks for more restraint. In the first days at altitude it is best avoided or kept very modest: it dehydrates, it disturbs the breathing drive you rely on during sleep, and its effects are felt more strongly in thin air. Once you are well acclimatised, a glass of Argentine Malbec or Peruvian wine with dinner is a fair reward — the timing is what matters. Treat the first high days as the patient ones, and let the celebration follow the acclimatisation.