How Food Provides Energy

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Food is a mixture of nutrients that produce energy for the body, stimulate growth, and maintain life. The 6 classes of nutrients:

  1. Carbohydrates
  2. Protein
  3. Fats
  4. Vitamins
  5. Minerals
  6. Water

Of these six nutrients, only the first 3 provide calories in the form of energy for the body: carbohydrates, protein and fat:

  • 1 gram of carbohydrate = 4 calories
  • 1 gram of protein = 4 calories
  • 1 gram of fat = 9 calories

Now that you know how many calories each of these 3 macronutrients provide, what ratios should you consume them in?

  • 18% Protein, 29% Fat, 53% Carbohydrates – Example nutrient ratio (USDA)
  • 10% Protein, 25% Fat, 65% Carbohydrates – Example nutrient ratio (Outdoor Herbivore)

This answer varies depending on the source, but most sources agree that carbohydrates should make up the bulk of your calories, followed by fat and protein.

Long distance thru hiking can burn 4,000 – 5,000 calories per day, so calorie density is key to sustaining energy needs. If fat makes up more than the combined calories of a protein and carbohydrate, why not just focus on a ratio that is highest in fat? Read on!

Why are carbohydrate calories so important?

Carbohydrates are the most important macronutrient to over-consume when it comes to backpacking (or any form of endurance activity) because the primary purpose of carbohydrates is to provide energy. Carbs break down into glucose for immediate energy needs and the surplus is stored as glycogen for future energy needs.  Once glycogen stores are filled, the remaining calories are converted into fat.

The type of carbohydrates consumed is important. There are 2 types of carbohydrates – complex and simple.

  • Simple carbs (sugar) provide a quick burst of energy. Examples: candy bars, energy bars, packaged baked goods, candy, soft drinks.
  • Complex carbs (starches) provide sustained energy. Examples – whole grain pasta / bread, barley, millet, brown rice, oats, quinoa, buckwheat, vegetables, beans, lentils.

Backpackers should focus primarily on complex carbohydrates. Complex carbohydrates are the body’s best source of energy. They are broken down into glucose more slowly than simple carbohydrates and thus, provide a sustained caloric release that makes it possible to perform intense exercise for an extended duration.

Why are carbs maligned by dieters if they are so essential for energy? Because less simple carbs is the key, not less complex carbs. Confusion arose when the word “simple” was dropped, making it seem all carbohydrates (including complex) were bad.

Why are fat calories so important?

The body depends on burning calories from fat (lipids) once it burns through calories from carbohydrates. Fat serves as the storage substance for the body’s extra calories. We seem to have an unlimited storage capacity for fat, making it our largest reserve of energy. Yet, fat is slow to digest and does not convert into quick energy. That is because the primary purpose of fat is to provide cell structure, a process that requires breaking down the fat and transporting it to cells. This process can take several hours. This is why it is important to have a reserve of fat cells available much before an activity rather than relying on them as a quick source of energy. Fat is also important for cushioning vital organs in the body, insulating the body so it can keep warm.

  • There are two types of fat – saturated and unsaturated. Saturated fats are from animal origins and unsaturated from plant sources.

Hiking long distances in mountainous terrain can burn up to 5,000 calories per day. Since fat provides 9 calories per gram, hikers do need to consume a greater amount of fat to make up for lost calories. We suggest adding an extra amount of fat gradually to the diet and to focus predominately on non-animal (unsaturated) sources to prevent arterial clogging and strain on the heart. Reliable and healthy high fat sources include nuts, seeds, coconut, and olive oil.  See list of vegetarian fats.

What about protein?

Recall, the calories per weight is the same for protein as for a carbohydrate (1 gram equates to 4 calories). However, this is somewhat misleading as only some (or none) of the amino acids from protein are usable for fuel. Protein does not serve as an energy source. In fact, protein will only be used as a fuel when carbohydrates and fat storage is inadequate. The primary role of protein is for construction of DNA cells. Protein is an essential nutrient for maintaining muscles, bone, skin, hair, and other tissues. Failing to take in adequate carbohydrates will require the body to use protein as an energy source, which can limit your ability to maintain muscle and tissue. 

There is a common misconception out there that we need a lot of protein – in fact only 1 in 10 calories should come from protein.* The problem is that most people get too much protein. Any excess protein not needed for cell maintenance is excreted from the bowels. A diet relying on animal products is not necessary especially when eaten in high amounts, as it is directly wasted. This also applies for high protein plant-based sources as well – such as soybeans. The protein fixation – even for vegans – is unwarranted. If you eat a diet that incorporates a large basis of grains/legumes and a fair amount of nuts/seeds, you will get an adequate amount of protein. Protein is in almost every food with the exception of sugar, alcohol, and fats. Relying on protein as a fuel is a bad idea. More information on the protein myth by Physicians Committee for Responsible Medicine (PCRM). Read more from wikipedia about how protein works as a nutrient.

Vitamins & Minerals

With the exception of sugar, almost all foods consumed contain essential minerals. Minerals help the body produce chemical reactions. Minerals include iron, calcium, phosphorus, sodium, potassium, iodine, magnesium, zinc, and copper.

Fat-soluble vitamins

The 4 fat-soluble vitamins include: A, D, E, and K. They require body fat (lipids) in order to be absorbed into the body and can be stored in body tissue for long periods. Taking too much of these 4 vitamins can result in having too much of these vitamins present in the body, leading to hypervitaminosis.

Each vitamin has a specific role.

  • Vitamin A is needed for strong bones, good vision, and healthy skin. It is found in dark green and yellow fruits and vegetables.
  • Vitamin D helps calcium and phosphorus for strong bones, including teeth. Vitamin D is obtained from sunlight.
  • Vitamin E helps to protect vitamin A and red blood cells. It is found in a wide variety of foods.
  • Vitamin K is made within the body by bacteria from the intestinal tract. It is also found in spinach, kale, and cabbage.

Water-soluble vitamins

Water soluble vitamins require water in order to be dissolved and are excreted quickly from the body through urine. These 9 water-soluble vitamins include: 8 B vitamins and Vitamin C. It is important to consume these vitamins daily. B vitamins help to convert carbohydrates into energy, and break down fats and proteins to maintain the nervous system. Vitamin C helps keep the immune system strong. The importance of water soluble vitamins are numerous -

  • Thiamine (B1) helps convert food into energy and maintain the nervous system.  Found in oysters, green peas,  lima beans and enriched products.
  • Riboflavin (B2) helps convert food into energy and generate glutathione, an enzyme that rids the body of free radicals.  Found in green leafy vegetables, dairy, enriched products.
  • Niacin (B3) helps convert food into energy.  Found in peanuts, eggs, mushrooms, enriched products.
  • Pantothenic acid (B5) helps convert food into energy and control stress by releasing hormones from the adrenal gland. Found in almost all foods.
  • Pyridoxine (B6) helps convert food into energy and cures hundreds of health conditions.  Many Americans are deficient. Found in whole grains, beans, and some fruits.
  • Cyanocobalamin (B12) helps convert carbs into energy, form red blood cells and maintain the nervous system. Found in dairy, meat, vegetarian support nutritional yeast.
  • Folic acid helps convert carbs into energy and helps form the genetic material DNA and RNA to support cell growth. Found in all vegetables and enriched products.
  • Biotin maintain metabolism and helps strengthen fingernails.  Found naturally in most foods.
  • Vitamin C or ascorbic acid builds the connective tissue for cells and keeps blood vessels, gums and teeth healthy. It also helps the body to absorb iron. Found in fruits and vegetables.

Getting Vitamins & Minerals on the Trail

Like minerals, chemical reactions in the body require vitamins, and a lack or excess of any one can interfere with the function of another.  A deficiency impacts your performance and weakens immunity. We know that eating a wide variety of foods ensures we’ll get the appropriate ratio of macronutrients, but this does not guarantee we’ll get recommended daily allowance of vitamins and minerals. It is not easy getting a diet of fresh foods on the trail. Hikers predominately rely on cooked and packaged foods, thus getting adequate levels of vitamins is often an issue. We fully recommend taking a multivitamin for daily life and especially on the trail. And eat as much fresh, raw foods when you get into town. Try sprouting on the trail, as well.

Water

Every cell in the body is dependent on water to survive. Water is essential to assimilate nutrients, eliminate waste, and regulate body temperature. Drink plenty of it!

Conclusion

The key is to get a variety of food, mainly in the form of complex carbohydrates. Don’t worry about calculating the caloric percentages you need – just incorporate a variety of whole grains, dried fruits & vegetables, nuts, seeds, and non-hydrogenated oils into your diet. Make sure you are indeed getting a varied diet. In particular to the U.S. there is a “deception of variety” when purchasing package foods. With all those brand choices, it may seem that you are purchasing a wide variety, but close scrutiny of the ingredients reveals otherwise Corn Fed America.

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