Guide

Trail food is engineered for one metric: calories per gram carried. That's a sensible objective for a through-hiker covering thirty kilometres a day, and it's why the shelf is full of sugar.

For a day hike or a weekend camp, the goal is different. You want steady energy over eight hours, not maximum fuel density, and the standard trail-food aisle is poorly matched to that.

What exercise does to the number

Worth setting up first, because it changes the whole calculation.

Sustained moderate exercise — which is what hiking is — increases glucose uptake into muscle through a mechanism that doesn't need insulin. Blood sugar tends to fall during and after, and the after can last many hours. Overnight lows following a long day of walking are common and catch people out.

Uphill effort and high altitude can push the other way temporarily, via adrenaline. The general direction over a full day is still downward.

If you use insulin or a sulfonylurea, that means two things: carry fast carbohydrate specifically for treating lows, kept separate from your food, and expect that your usual doses may need adjusting for a big day. The dose part is a conversation with your care team before the trip.

The trail-mix problem

Standard trail mix is nuts, raisins and chocolate. The nuts are excellent. The raisins are the highest-load dried fruit going, and the chocolate pieces are confectionery.

Make your own and the whole thing changes: almonds, walnuts, pumpkin seeds, dried edamame, coconut flakes, and a small amount of very dark chocolate. The result is a mix with a glycemic load in low single digits per handful instead of the mid-teens.

The same logic applies to energy bars. Most run GL 20 or higher and are, functionally, a flapjack with a fitness photograph on the wrapper. The ones built on nuts and seeds rather than dates and syrup are a different product; the ingredient list distinguishes them in about three seconds.

What actually packs well

Day-hike food that survives a rucksack and doesn't spike:

• Hard cheese — travels for a full day, zero carbohydrate
• Cured meat, jerky, biltong — check for sugar in the cure; some brands are heavily sweetened
• Boiled eggs — fine for the first day if kept cool
• Tinned or pouched fish — heavier, worth it for a lunch stop
• Nut butter sachets — the most calorie-dense low-GL item available
• Seed crackers and oatcakes — oatcakes are a genuinely moderate-GL biscuit
• Dark chocolate, 85% — around 4 g of carbohydrate per two squares
• Apple or pear — heavy for their calories, and the best morale per gram on this list

Multi-day, where it gets harder

Dehydrated camping meals are built on rice, pasta or potato, and they're mostly high-GL by design. A standard pouch commonly carries 60 to 80 g of carbohydrate.

Three adjustments help. Add fat — a sachet of olive oil or a knob of butter stirred in slows the whole meal and adds calories you'd otherwise carry as more carbohydrate. Add protein, in the form of a foil pouch of chicken, tuna, or a scoop of unflavoured protein powder. And eat half the pouch with something else rather than the whole thing alone.

Lentil and bean-based dehydrated meals exist and are considerably better on both fibre and load. Dried refried beans and instant lentil soup pack down as small as anything else on the shelf.

For breakfast, overnight oats made in a jar with milk powder and seeds beat instant porridge sachets, which are usually sweetened and very fast.

Water, and what goes in it

Hydration matters more than usual, and dehydration alone raises blood glucose by concentrating it.

Plain water for most of it. Electrolyte tablets for long or hot days — check whether yours are the sugar-free kind or the carbohydrate-loaded sports version, because both exist in similar packaging.

Sports drinks have a place here that they don't have at a desk: on a genuinely long, hard day, drinking your carbohydrate is efficient. That's a real use case, and it's specific to sustained effort rather than to a Sunday walk.

Cold weather changes things

Autumn and winter hiking add two complications worth planning for.

Cold suppresses thirst, so dehydration creeps up while you're drinking less than you would in summer — and dehydration raises blood glucose by concentration alone. Hot drinks in a flask solve the palatability problem better than cold water does.

Cold also affects equipment. Insulin shouldn't freeze, and it will if left in an outer pocket overnight below zero. Meters and CGM readers behave unreliably at low temperatures, and phone batteries die fast in the cold, which matters if your CGM readout lives on your phone. The fix for all of it is the same: keep the important things in an inside pocket, close to your body.

Glucose tablets stay usable when frozen. Gels and chocolate become difficult to eat at the exact moment you'd need them quickly.

The kit that isn't food

Fast carbohydrate for lows, in a pocket rather than buried in the pack — glucose tablets are compact, don't melt, and don't get eaten as a snack by accident.

Twice the medication you think you need, split between two bags in case one goes into a river. Insulin kept from freezing overnight and from cooking in a hot tent; a sock in the middle of the pack works for both. Testing kit in an accessible pocket, since a meter at the bottom of a rucksack in the rain doesn't get used.

And someone in the group who knows you have diabetes and what a low looks like. That's the piece of equipment people most often skip.