The food you bring should have a high calorie/weight ratio. Things like canned beans, canned pasta, while calorie dense, are contain a lot of water, which adds to the weight.
Flash-frozen or dehydrated foods are the meal of choice for most campers, but are often much more expensive. These meals require boiling water to prepare, and need to rehydrate (sometimes up to 20 minutes) before eating.
Meals Ready To Eat (MRE) are a US Military Ration, designed to be eaten immediately. These are fully hydrated meals, and as such weigh more than other food sources. They are a good choice, if you're willing to make the weight sacrifice. They come with self contained, exothermic heaters, which can eliminate the need for a water boiling system
DIY Trail meals offer much more granular control over what your eating, at the expense of convenience. https://www.reddit.com/r/trailmeals/top/
A lot of this is personal choice, but the basics are the same. You want to bring food that supplies proteins, carbohydrates, simple sugars, and fats. All of these metabolize at different rates, meaning you get a steady amount of energy throughout the day. The glycemic index of a carbohydrate represents how quickly its consumption increases blood sugar levels. Values range from 1 (the slowest) to 100 (the fastest, the index of pure glucose). However, how quickly the level actually increases also depends on what other foods are ingested at the same time and other factors. The glycemic index tends to be lower for complex carbohydrates than for simple carbohydrates, but there are exceptions. For example, fructose (the sugar in fruits) has little effect on blood sugar.
The following also influence a food’s glycemic index:
Processed, refined, or finely ground foods tend to have a higher glycemic index. ##Type of starch Different types of starch are absorbed differently. For example, potato starch is digested and absorbed into the bloodstream relatively quickly. Barley is digested and absorbed much more slowly.
The more fiber a food has, the harder it is to digest. As a result, sugar is absorbed more slowly into the bloodstream.
The riper the fruit, the more sugar it contains, and the higher its glycemic index.
The more fat or acid a food contains, the more slowly it is digested and the more slowly its sugars are absorbed into the bloodstream.
How a food is prepared can influence how quickly it is absorbed into the bloodstream. Generally, cooking or grinding a food increases its glycemic index because these processes make food easier to digest and absorb.
The way the body processes food varies from person to person, affecting how quickly carbohydrates are converted to sugar and absorbed. How well a food is chewed and how quickly it is swallowed also have an effect.
A List of common foods with their glycemic index: https://extension.oregonstate.edu/sites/default/files/documents/1/glycemicindex.pdf
Snacks should be heavier on simple sugars, protein, and carbohydrates. A high fat food can make you feel sluggish or even sick. Snacks are often eaten on the trail
- GORP - Branola, Oatmeal, Raisins, Peanuts
- Pita Bread
- Hard Salami - Find salami that is shelf stable
- jerky - Good protein, but usually has a lot of sodium. Be sure to match your water intake
- Knorr Pasta Sides + Chicken Pouch
- Dehydrated Soup