Basic Thru-Hiker Nutrition Part 1: Macros and Micros
Nutrition is an essential part of life and a topic of constant conversation among thru-hikers. While the general concept is simple – you get hungry, you eat, you walk- there is a lot going on behind the scenes that can impact your mood, bodyweight, and energy levels throughout your journey. In this three-part series, I’ll give a crash-course in nutrition for thru-hikers whereby you’ll gain a basic understanding of nutritional concepts, find out how to calculate your required food intake, and learn to pick the best trail food for staying healthy on your hike.
In this first part I’ll ‘set the table’, so to speak, with the basic concepts and definitions of nutrition and the elements you should pay attention to when choosing your food. Bare with me while I attempt to explain the idea of calories, macronutrients, and micronutrients in a way that new thru-hikers can understand.
Calories are a unit of energy, pure and simple. The term “calorie” is a bit of a misnomer, as it actually refers to a “kilocalorie”, aka “kcal” (1,000 calories = 1kcal), which is the amount of energy required to raise one gram of water by one degree Celsius (Source). Whenever a nutrition label refers to a calorie, it is actually calculating the number of kcals. (Fun fact: to test the number of calories in a food item, scientists use a “bomb calorimeter” to zap it with energy until it combusts. The amount of energy it takes to break down the food is how many “calories” the item’s package will be stamped with).
Your body uses calories to fuel all its functions including digestion, sleep, and, yes, hiking. They are essential for human life and health, and all foods have calories of varying amounts. A calorie is comprised of both macronutrients and micronutrients.
Macronutrients are the major providers of energy (calories) in food. Macronutrients include Carbohydrates, Protein, and Fat.
Carbohydrates provide fuel for your body. After you finish a meal, the carbohydrates you consumed are broken down into smaller units of sugar, called glucose, which are absorbed out of your digestive tract and into your bloodstream. The glucose is transported through your bloodstream to supply energy to your muscles and other tissue, and most importantly to the brain and central nervous system. Additionally, as carbohydrates are burned as the body’s main source of fuel, they prevent the breakdown of proteins for energy which in turn assists with muscle retention during prolonged exercise. As a matter of general health, it is recommended that you consume carbohydrates which have a limited amount of added sugars and are minimally processed – instead focusing on whole grains. Many people get confused about carbohydrates (Good? Bad? High? Low?), but the important thing to remember is that the quality is more important than the quantity. 1 gram of carbohydrate = 4 calories.
Sources of Carbohydrates:
- Whole Grains
Protein is one of the body’s main building blocks. Every cell contains protein and it is used to help your body repair and create tissue structures that form your organs, muscles, hair, skin, bones, and more. It makes up the enzymes that fuel chemical reactions in your body which carry oxygen to your blood and help regulate metabolism. Protein is comprised of a string of amino acids, some of which are created in the body and others which must come from food. Animal sources of protein (e.g. meat) offer a complete protein because it all the necessary amino acids are present. Other sources of protein such as fruits, vegetables, and nuts, lack one or more of the essential amino acids and must be consumed with others in order to provide the necessary amino acids (source). Because of this, vegetarians must be conscientious about consuming multiple types of non-animal protein in order to receive all the amino acids necessary to create the protein structure. 1 gram of protein = 4 calories.
Sources of Protein
- Animal sources (meat/poultry or meat alternatives)
- Dairy (Eggs/Milk/Yogurt)
- Legumes (beans) and Lentils
- Soy products
- Nuts and seeds
Fat is often demonized as “unhealthy”, but in fact it plays a crucial role in our health. Again, what matters most here is the quality of the fats you are consuming rather than the quantity (eating fat doesn’t make you fat, eating too much does!). Fats provide not only an energy source, but also the essential function of assisting in the absorption of vitamins and nutrients from your food. There are many kinds of of fats, but a good rule of thumb is to focus on consuming unsaturated fats (oils, fish, nuts) and avoid saturated fats (trans fats, hydrogenated oils, lard) when possible. Cholesterol, a fat-like substance found in animal products such as meat, eggs, and butter, should be consumed in moderation. Fat is the most calorically dense macronutrient, where 1 gram of fat = 9 calories.
Sources of “Good” (unsaturated) Fats:
- Oils (coconut, olive)
- Nuts (cashews, almonds, walnuts)
Micronutrients consist of the vitamins and minerals that help support overall bodily health as well as metabolism and neurological functions. Micronutrients do not provide fuel (e.g. calories) to the body the way that macronutrients do, but they play an essential role in growth and health nevertheless. For example, Vitamins A and C aid in bone formation, immune system support, and eye and skin health. Minerals such as calcium and iron support nerve and muscle function as well as oxygen delivery and wound healing. Without these minerals, many of which the body cannot produce on its own, you are subject to a number of debilitating diseases. An example of this is when British sailors, centuries ago, would live for months on end without fresh fruits or vegetables (the main sources of Vitamin C) and then suffered from scurvy, which was often fatal. Without getting too detailed, the the most common vitamins and minerals that assist in keeping us healthy are Vitamin B6, Vitamin C, Vitamin E, Magnesium, Calcium, and Iron (Source). Luckily, if we’re eating a balanced diet then we generally get all the micronutrients needed from our food – especially from the ones previously mentioned. Supplementation through multivitamins is one way to ensure you’re getting adequate dosage, but it should not be completely relied upon for your micronutrient intake.
Foods high in micronutrients:
- Chard, collard greens, kale, spinach
- Bell peppers
- Sweet potatoes
- Berries and citrus fruit
- Almonds, cashews, and peanuts
- Chicken, turkey, lamb, and beef
- Salmon, halibut, shrimp, and tuna
- Eggs and yogurt
Putting It Together
Understanding what calories, macronutrients, and micronutrients do is the baseline of nutritional knowledge for all active individuals, especially thru-hikers. We’ve established that humans burn calories as fuel and that this energy comes from macronutrients in the the food we eat. Also of importance are the micronutrients (vitamins and minerals) in our food which our bodies need in order prevent disease and support our immune systems. As thru-hikers, we need to ensure that we are taking in an adequate amount of calories to fuel our adventure while feeling healthy and strong along the way.
In Part 2, we’ll discuss how to figure out how many calories you need per day and why this matters.
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