Fuel for the Summit: How to Eat and Hydrate Above 3000 Metres

High Altitude Nutrition: Fueling Your Body for the Climb

To better understand the importance of nutrition at high altitude, we spoke with two experts with complementary approaches:
Dr. Maurizio Fasano, an endocrinologist and sports nutritionist specialising in Mountain Medicine (Enervit Nutrition Specialist – Mountain Medicine Master UIAGM, ISSN Certified, SINSeB Certified), and
Ioris Turini, an IFMGA mountain guide and high-altitude athlete with years of mountain experience.

Why High Altitude Nutrition Matters

Dr. Fasano, why is nutrition so important when climbing above 3,000 metres?

“A proper diet not only provides the necessary energy but also supports acclimatisation and helps prevent altitude sickness. People often focus solely on physical training, but without the right nutritional support, performance can really suffer.”

Ioris, do you follow Dr. Fasano’s advice? How much does nutrition impact your performance?

“Nutrition is key in everyday life and even more so when preparing for climbs. You need a well-stocked tank of quality fuel. Plus, you have to get used to eating during exertion. Testing food in training helps you discover what works for you—having tried and tested snacks makes your effort more manageable.”

What to Eat Before a High-Altitude Climb

Dr. Fasano, what nutritional strategies do you recommend in the days before a climb?

“Altitude often suppresses appetite, so it’s vital to maintain a regular, balanced diet. The day before, I recommend a load of complex carbohydrates—whole grains, rice, potatoes, and bread—to stock up on precious muscle energy.”

Ioris, have you adapted this in practice?

“I avoid overpacking heavy food, so I prepare well in advance. Hydration and energy storage in the days before a climb are crucial. I’ve learned the body can burn different fuels, but some work better—like dry wood compared to green logs or old tyres. Fruit, vegetables, whole carbs and a balance of protein are your dry wood.”

Hydration and High Altitude Nutrition

And hydration, doctor?

“Being well-hydrated before you even start is crucial. At altitude, it’s harder to stay hydrated, so drink plenty the day before. During the climb, alternate water with isotonic drinks to replenish sugars and minerals lost during exertion.”

Ioris, how do you manage hydration on the mountain?

“We tend to drink less than we should, due to cold, wind and fatigue. That’s why starting off well-hydrated is essential—it’s tough to catch up once you’re up there.”

The Role of Dinner Before the Climb

The dinner before the climb matters too, right Dr. Fasano?

“Absolutely. I recommend a light yet nourishing dinner with complex carbs, lean protein and fresh vegetables. Avoid greasy food—it slows digestion and can disturb sleep, which is already affected by the altitude.”

And you, Ioris?

“I keep it light and cut back on seasoning. Especially in huts above 3,000m, your body is already working hard to adapt—digestible food is a must.”

Best Snacks for High-Altitude Ascent

What snacks do you recommend during the ascent, Dr. Fasano?

“Go for snacks that are easy to digest and quick to absorb: dried fruit, nuts, energy bars or sport-specific gels. Drink little and often, and eat every 30–45 minutes—don’t wait until you’re hungry or thirsty. This keeps your energy levels steady and avoids sudden crashes.”

Ioris, any practical advice on snacks?

“There are loads of options out there, but test them during your mid-altitude training. I always like to carry a sandwich with something savoury.”

Preparing for a Successful Climb

Preparing properly for high altitude nutrition means tackling your climb with energy, focus and awareness. With the right physical and nutritional training, each adventure becomes a rewarding journey.

Our advice? Train mindfully and enjoy the process—each step brings you closer to the confidence and strength for your next big goal.