Backpacking is energy intensive. It is essential enough food is taken to maintain both energy and health. As with gear, weight is critical. Consequently, items with high food energy, long shelf life, and low mass and volume deliver the most utility. Satisfaction is another consideration, of greater or lesser importance to all hikers. Only they can decide whether it's worth the effort (and trade-off against other gear) to carry fresh, heavy, or luxury food items. The shorter the trip and easier the conditions the more feasible such treats become.
In all cases, both kit and fuel necessary to prepare and serve foodstuffs selected is part of the equation. Small liquid and gas fueled campstoves and ultralight cooking pots are the norm. Increasingly campfires are prohibited.
While most backpackers consume at least some specially prepared foods, many mainly rely on ordinary low moisture household items, such as cold cereal, oatmeal, powdered milk, cheese, crackers, sausage, salami, dried fruit, peanut butter, pasta, rice, and commercially packaged dinner entrees. Popular snacks include trail mix, easily prepared at home; nuts, energy bars, chocolate, and other forms of candy for quick energy and satisfaction. Jerky and pemmican are high-energy and lightweight. Coffee, tea, and cocoa are common beverages.
Domestic items are typically repackaged in zippered plastic bags. Canned or jarred food, except for meats or small delicacies, is avoided: their containers and moist contents are usually heavy, and the metal or glass must be packed out. Food dehydrators are popular for drying fruit, jerky, and pre-cooked meals.
Many hikers use freeze-dried precooked entrees for hot meals, quickly reconstituted by adding boiling water.
An alternative is Ultra High Temperature (UHT) processed food, which has its moisture retained and merely needs heating with a special, water-activated chemical reaction.
These have roots in the U.S. military's MRE, and eliminate the need for a stove, fuel, and water. Against this, they are heavy, the water is already in the food, and they require their own fuel. Still, they have some attractions.
Do not need to be rehydrated or heated, useful where flames are prohibited and water is scarce.
Are very durably packaged
Contain a full meal complete with snack and dessert in every package
Offer a great deal of variety in each meal, including condiments
Individually package their components, allowing some to be stored accessibly and eaten on the move
MREs can be difficult to find in retail stores, though a good selection is often available in a (U.S.) military surplus store.
Specialized cookbooks are available on trailside food and the challenges inherent in making it. Some focus on planning meals and preparing ingredients for short trips. Others on the challenges of organizing and preparing meals revolving around the bulk rationing prevalent in extended trail hikes, particularly those with pre-planned food drops.