Estimate food needed for a hiking trip.
Hiking energy expenditure is calculated from the metabolic equivalent of the activity, and the mass that matters is you plus the pack — a 12 kg pack is a 17 percent increase in the load being lifted up every step. Terrain sets the MET value, from 5.3 on flat trail to 9.5 on steep alpine ground, so identical hours on different terrain can differ by 80 percent in energy cost. Resting metabolism continues on top of that and is not negligible over a full day. Converting to pack weight uses about 450 kcal per 100 grams, which requires deliberately fat-dense food choices — general groceries average well under 300.
Hiking energy
kcal = MET x (body kg + pack kg) x hours
Food weight
Grams per day = (hiking kcal + body kg x 22) / 4.5
A planning estimate based on population-average metabolic equivalents, not nutritional or medical advice. Individual energy needs vary substantially with fitness, altitude, temperature, metabolism and health conditions. Consult a qualified professional for dietary advice, particularly if you have a medical condition or are planning extended or high-altitude trips.
Because you lift it with every step and up every metre of ascent. The MET formula scales with total mass moved, so a 12 kg pack on a 72 kg hiker raises energy expenditure by roughly 17 percent. On a multi-day trip that is several hundred calories a day of extra food to carry — which itself adds weight.
Because pack weight is the binding constraint. Fat delivers 9 kcal per gram against 4 for carbohydrate and protein, so nuts, nut butters, oils, cheese and cured meat carry far more energy per gram than anything fresh. Ordinary groceries average under 300 kcal per 100 g, which means a third more weight for the same energy.