Eating and drinking at high altitude: what changes
Appetite fades, you lose more water and everything feels harder. Here is what altitude does to eating and drinking, and how to keep fuelled when the air is thin.
- 3,000 m+Appetite often dips
- 3 to 4 LA rough daily guide
- 6 minRead
Lauren Jones, Peaksted co-founder · Training advice reviewed by Nathan Gee · 14 October 2026At altitude, the hardest part of eating is not what to eat. It is that you simply do not want to. Plan for that, and you are most of the way there.
Appetite often drops at altitude, while dry air and exertion can change fluid needs. Eat small, carbohydrate-rich snacks regularly, carry safe water and drink to thirst. Hot drinks and soup can help you keep eating and drinking without forcing a litre target.
Four things altitude does to eating
Pick one, then flip the card for what to do.
You are not hungry, and you need food more than ever
Many people find their appetite fades at higher altitude, often noticeably above about 3,000 m. Food can start to look unappealing, and it is easy to under-eat for days.
Why it matters: Your energy needs rise as you climb and work harder, while appetite falls. Over several days the gap adds up and leaves you flat.
Dry air and faster breathing dry you out
The air is thinner and drier, and you breathe faster and deeper, so you lose more water from your lungs. You also pass more urine at first as your body adjusts.
Why it matters: You can get dehydrated without feeling especially hot or sweaty, and dehydration can make you feel worse and blur with altitude symptoms.
Carbohydrate is easiest to use
Many guidelines favour carbohydrate-rich food at altitude, because it needs a little less oxygen to turn into energy than fat does, and it is easier to eat when your appetite is low.
Why it matters: At altitude, oxygen is in shorter supply. Carbohydrate-based meals are generally easier on your stomach and your breathing.
Make it easier on yourself
Alcohol feels tempting at camp, but it dehydrates, disrupts sleep and can feel stronger at altitude. Heavy, greasy meals and very spicy food can also sit badly.
Why it matters: Sleep and recovery are already harder at altitude, and anything that makes them worse adds up across several days.
A rough guide by height
Everyone is different, so this is a guide, not a prediction.
| Altitude | What many people notice |
|---|---|
| Below about 2,500 m | Normal appetite for most people. Standard fuelling and fluid advice applies. |
| About 2,500 to 3,500 m | Some people notice a dip in appetite and slightly higher fluid needs. |
| About 3,500 to 5,000 m | Appetite is often noticeably lower. Eating on a schedule matters, and so do hot drinks. |
| Above about 5,000 m | Reduced appetite is common. Small, frequent, easy food and fluid are the priority. |
Food and drink help you feel and perform better, but they do not prevent altitude illness. Gradual acclimatisation and descending when symptoms worsen are what matter.
Heading high?
These guides cover the route, the acclimatisation and the physical side.
- Understanding altitude and acclimatisation
How your body adapts and what that means for pacing.
- Everest Base Camp altitude explained
Sleeping heights, rest days and what to expect.
- Kilimanjaro altitude explained
Why the route and speed matter.
For general advice on altitude illness, see the CDC Yellow Book on high-altitude travel.
Eating and drinking at altitude: FAQ
Why do I lose my appetite at altitude?
It is common, and thought to be linked to how your body responds to lower oxygen levels and the altitude itself. It tends to start above about 3,000 m and gets stronger the higher you go. It is not a sign you are failing.
How much water should I drink at altitude?
There is no universal litre target. Dry air and exertion can increase losses, but drinking too much is also harmful. Plan safe water access, drink to thirst and seek medical advice if you feel unwell rather than assuming symptoms are dehydration.
What should I eat at high altitude?
Carbohydrate-rich, easy-to-eat food in small, regular portions: rice, noodles, bread, potatoes, soup and sweet snacks, with some protein and fat for balance. Eat what you can, often.
Does eating differently prevent altitude sickness?
No. Good nutrition and hydration help you feel and perform better, but they do not prevent altitude illness. Gradual acclimatisation, appropriate pacing and descending when symptoms worsen are what matter.
Is nausea at altitude a food problem?
It can be, but nausea, a headache and loss of appetite are also early signs of acute mountain sickness. If symptoms are getting worse or you are confused or unsteady, rest, do not go higher and descend if needed.
Should I take supplements at altitude?
Most trekkers do not need them. Focus on food, fluid and acclimatisation first. If you are considering iron or other supplements, speak to a doctor before you go.
Altitude makes everything harder, including eating. See how the numbers stack up in Everest Base Camp altitude and Kilimanjaro altitude, then check your readiness.
Check my readinessSources and scope
This is general sports-nutrition information, not personal dietary or medical advice. Altitude advice follows the CDC Yellow Book, which notes that fitness does not change your risk of altitude illness. Fuelling guidance follows the joint position statement Nutrition and Athletic Performance (Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine, 2016), adapted for trekking. Fluid needs at altitude vary; the guide avoids a fixed daily drinking target. Altitude illness guidance follows Luks and colleagues, Wilderness Medical Society Clinical Practice Guidelines for the Prevention, Diagnosis, and Treatment of Acute Altitude Illness: 2024 Update (Wilderness and Environmental Medicine, 2024). Lauren Jones is studying towards the NASM Sports Nutrition qualification. If you have a health condition or are planning a trek above 3,000 m, talk to a doctor or a travel clinic before you go. Training advice reviewed by Nathan Gee, BSc Sports Science.
