Field nutrition for aid workers and humanitarian field teams

Written by James Frost, founder of Flaming Phoenix and the maker of Phoenix Bars. Updated November 2026.

Quick answer: Carry a personal reserve of sealed, no-cook, calorie-dense food that keeps without a fridge, sized to cover one to three days on its own. At 2,500 calories a day, a three-day reserve of dense food such as nuts and high-calorie bars weighs about 1.7kg.

NGO and humanitarian field teams working in remote or disrupted places need food for themselves that keeps without refrigeration, is light to carry, dense in calories, and easy to eat when there is no time or facility to cook. This guide covers food for the staff themselves on long days in difficult conditions, not food for affected populations, which is a separate and highly specialised field with its own regulated products and supply chains.

Why field-team nutrition is its own problem

Field and response teams often deploy at short notice into places where the ordinary food supply has been disrupted, where there is no kitchen, no fridge, and no certainty about the next reliable meal. Days are long, the work is physical, meals are irregular, and staff still have to stay sharp and make good decisions. In that environment, the food a worker carries for themselves has to travel well, keep without refrigeration, and be edible with no preparation. Much of what a team eats will be sourced locally or come from standard rations, but a personal reserve of calorie-dense food covers the gaps when nothing else is available. The same readiness logic underpins all emergency food preparedness.

What field-team food needs to do

Food carried by a deployed worker has to do several things at once: keep safely without refrigeration, last a long time unopened so it can be pre-positioned in field kits, pack a lot of energy into little weight and space, be edible with no cooking, and suit a mixed international team with varied diets. Anything that spoils quickly, needs preparation, or only works for some team members fails one of those tests. Expedition teams apply much the same tests when choosing the best energy bars for expeditions.

Shelf life matters more here than people expect, because field kits and deployment bags are often packed in advance and held ready. A food with a long shelf life can sit in a go-bag or a pre-positioned store for many months and still be good when it is needed. As a reference point, sealed high calorie bars commonly carry best-before dates many months ahead and some keep for up to two years, long enough to pre-position rather than restock every few weeks.

The energy demand of field deployment

Field work is demanding: long hours on foot, manual tasks, broken sleep, stress, and often heat or cold on top. The practical aim is steady, reliable energy across an unpredictable day rather than depending on sit-down meals that may not happen. Food that delivers a lot of energy per gram makes that possible without adding weight to a pack already carrying equipment, which is the principle behind these calorie-dense foods. Where deployments run into the night or across shifting shift patterns, the same logic as night shift nutrition applies, keeping energy steady through the hours when it is hardest to maintain.

How much food should a personal reserve hold?

Enough to get you through one to three days if nothing else turns up. UK reference intakes are 2,000 calories a day for women and 2,500 for men, and long physical days in heat or cold push that higher. The weights below assume dense, dry food at about 4.5 calories per gram, such as nuts and high-calorie bars, and are rounded and approximate; they leave out water and packaging.

Water is the heavier problem: allow for it separately, because 2 to 3 litres a day weighs 2 to 3kg, several times a day's food. If your organisation issues a go-bag list, use it as the baseline and treat the table as a check on whether the food part is realistic.

Heat, cold and difficult conditions

Field deployments span climates, and food that holds up in one can fail in another. Many bars and snacks soften or melt in heat and harden or freeze in the cold, so test your reserve food in the conditions you expect before you rely on it. Chocolate and coated bars are poor choices for hot postings, while nuts, oatcakes and dense, fat-based bars cope better at both ends. At the end of a long day, a high-calorie porridge mixed with water is a filling, low-effort meal.

Mixed teams and dietary needs

International field teams bring a wide range of dietary needs, and field conditions make catering for all of them difficult. A reserve food that is vegan, gluten-free and fully allergen-labelled is the simplest way to cover most of a team with one product, but always check the label against each person's needs.

Where Phoenix Bars fit

I make Phoenix Bars, so weigh this section with that in mind. Alongside local sourcing and established field rations, they work as the personal reserve in a field kit: up to 557 calories in a compact, 120g bar, up to two years sealed (12 months for Cherry Bakewell) so they hold in pre-positioned kits, no cooking required, and vegan and gluten-free in every flavour, with full allergen information on each label. Customers have used them at both ends of the climate range: one found them easy to eat at -45°C on a South Pole expedition, and a Marathon des Sables runner said they kept their shape even in desert temperatures. Mixed with water, a bar becomes a porridge, using the method in how to make a Phoenix Bar into porridge. The Starter bundle (12 bars) is a straightforward way to assess them, and the Essential bundle (18 bars) suits stocking field kits or a deployment bag.

For NGOs and field-team logistics

If you are equipping field teams rather than yourself, the priorities are shelf life, dietary coverage across a mixed group, predictable energy that needs no preparation, and food that survives the climates your staff deploy into. Our high-calorie nutrition bars come in bundles suited to stocking deployment kits, and we can arrange bulk supply for organisations equipping their own field and response staff. Get in touch through the contact page to discuss it. This is supply for your deployed teams and field staff, not for population-level feeding programmes, which sit with specialist humanitarian food suppliers.

Frequently asked questions

What food do aid workers take on deployment?
Food that keeps without refrigeration, needs no cooking, packs a lot of calories into little weight, and lasts a long time unopened. In practice that means sealed high-calorie bars, nuts and dried staples, carried as a reliable personal reserve alongside whatever is sourced locally or supplied as standard rations.

How much food should be in a deployment go-bag?
Enough to cover one to three days on its own. At 2,500 calories a day that is 2,500 to 7,500 calories, or roughly 560g to 1.7kg of dense, dry food, with water planned separately.

What food keeps without refrigeration in the field?
Sealed, shelf-stable foods with a long shelf life, such as foil-packed nuts, oatcakes and sealed bars. Dried and concentrated foods keep safely without a fridge too, and can be carried or pre-positioned in field kits well in advance of a deployment.

How do you keep field food light?
Avoid anything wet or tinned that you do not need to carry, and choose energy-dense foods that provide more calories per gram. This keeps a worker's personal food reserve light enough not to add meaningful weight to a pack already carrying operational equipment.

Is the same food suitable for hot and cold climates?
Only if it is formulated to be. Many foods soften or melt in heat and harden or freeze in cold. Foods with a fat base that resists both extremes stay edible in whatever climate a team deploys into, even when one kit goes to a hot posting and then a cold one.

Can field food be pre-positioned in advance?
Yes, provided it has a long shelf life. Food that keeps for a year or more sealed can be packed into deployment bags and pre-positioned stores and stay good for months, so nobody has to keep restocking and the food is ready when a team deploys at short notice.

Written by James Frost, founder of Flaming Phoenix and the maker of Phoenix Bars. This is general guidance for individual staff, not advice from any aid organisation. Read more on the my story page.

Related guides

Fieldwork nutrition · Jungle expedition food · Offshore workers nutrition · Emergency services nutrition

Sources: NHS, Understanding calories; Phoenix Bar values from our own pack labels.