1.4: Nutrition

Learning Objectives

1. Describe the 3 (or 4) macronutrients.
2. Understand what each macronutrient’s role in the body is.
3. Understand Basal Metabolic Rate.

Steak and potatoes? Salmon and kale? Popcorn and soda? Our bodies run on what we ingest, and these choices make a massive difference in our health. As a kinesiologist in any field, questions about diet and nutrition are common because there is so much misinformation, fear, and fad diets circulating through social media that many people do not know what to believe.

Nutrition is the study of everything we eat and drink. Food and drink fuel the body for temperature regulation, physical activity, repair of tissues, and even thinking. The brain uses about 20% of ingested calories. People’s choices about what they consume make massive differences in their health and their body’s ability to grow and repair from exercise. In terms of all-cause mortality (everything that kills us) from cancer to heart disease to getting hit by a bus, most diseases have risk factors that we cannot change like our genetics, gender, or ethnicity but there are also lifestyle factors that we can change like nutrition and exercise. Broadly speaking, eating better, healthier food will reduce risk factors for many diseases. This is why it is so important to learn and understand the basics, because healthy eating is basic and it's important for all of us, since we all eat. Proper nutrition is also critical for building and fueling an athletic body, and the food intake will vary based on the athletic goals.

Food is often discussed in terms of its calories, and calories are units of energy. 1 kcal (1000 calories) is the amount of energy required to increase the temperature of 1kg (2.2lbs) of water from 0 Celsius to 1 Celsius. The Food and Drug Administration (FDA) set the average adult daily requirement for calories at 2000, and this number is commonly used as a starting point for most individuals, although true needs can vary greatly based on body composition, age, gender, and activity level.

Basal metabolic rate (BMR) is how many calories your body uses at rest. BMR is used in combination with your activity level to calculate how many calories are needed to maintain currency body composition at current activity levels. The largest use of calories is to keep the human body warm and alive. Calculate an estimate of how many calories you need here. Protein and carbohydrates have 4 calories per gram and fat has 9 calories per gram. (Alcohol has 7 calories per gram).

There are many diets advertised to consumers but usually the best intake of food for health and fitness is consuming the correct number of calories through fresh minimally processed foods of a wide variety.

Some of the more common diets are discussed below:

1. The DASH diet: focuses on reducing sodium intake to reduce high blood pressure, and promotes the consumption of whole grains, fruits, vegetables, low-fat dairy products, lean meats, and heart-healthy fish.
2. The gluten-free diet: recommended for people with celiac disease and gluten intolerance, this diet excludes foods containing gluten such as wheat, barley, and rye. It emphasizes fresh fruits, vegetables, and other foods without gluten.
3. Low-carb diets/Keto: focus on limiting carbohydrates, including grains, fruit, and starchy vegetables, to promote weight loss. This diet emphasizes whole, unprocessed foods and a de-emphasis of refined carbohydrates.
4. The macrobiotic diet: a health and wellness regimen based on Eastern philosophy, it combines certain tenets of Zen Buddhism with a vegetarian diet and supports a balance of yin and yang’s oppositional forces. The diet emphasizes whole grains, raw and cooked vegetables, small amounts of fish and seafood, and prohibits certain foods such as chocolate, tropical fruits, and animal products.
5. The Mediterranean diet: emphasizes small portions of nutritionally-sound food from plant sources, including vegetables, fruits, whole grains, beans, nuts, seeds, and emphasizes the use of healthy fats like olive oil. This diet also limits the consumption of red meat and processed foods.
6. Fad Diets: Unfortunately, there are a lot of people giving unhealthy advice to uneducated people that believe it. Most diets do not work because they are not sustainable for long periods of time. The goal of any solid nutrition advice is that a person should be happy to continue following those guidelines for the rest of their life. Setbacks are normal.

Anorexia, also known as anorexia nervosa, is a psychiatric illness that involves excessive preoccupation with one's weight and food intake. This condition leads to severe malnourishment and eventually organ failure. Although relatively rare, affecting only 0.9% of females and 0.3% of males in their lifetime according to the National Institute of Mental Health (NIMH), it exemplifies how an imbalanced diet can severely impact one's health.

In contrast, bulimia involves consuming large amounts of food followed by purging through methods such as vomiting, taking laxatives or diuretics. Unlike anorexia, individuals with bulimia typically maintain a normal weight, making the disorder harder to identify and diagnose. The signs of bulimia resemble those of anorexia, including fear of gaining weight, extreme dieting, and excessive exercise routines.

Having a basic understanding of eating disorders and other psychological illnesses is important in all fields of kinesiology because someone you work with may be using exercise and diet to an unhealthy obsession.

Nutrients are divided into two categories: Macro and Micronutrients.

Macronutrients

These are the three nutrients that we need daily and in large portions: protein, carbohydrates, and fat. Water is sometimes listed as a fourth macronutrient (and will be in this book). Protein, carbohydrates, and fat provide the energy needed for life and the building blocks to grow and repair a body.

Protein:

Function: Protein generally is used for muscle and bone growth and repair. Protein can be used for energy in starvation situations.

Proteins are made up of amino acids. There are 20 amino acids, 9 of them are “essential” meaning the human body cannot create them, so they must be ingested and derived from food sources. The other 11 amino acids are “nonessential” meaning the human body can repurpose other amino acids to create them if needed. Understandably confusing due to their naming, nonessential amino acids are still essential to human health. Protein can come from eating animal products like fish and eggs, but it is also possible to meet all of your protein requirements with a vegetarian/vegan diet.

Many people are not ingesting enough protein, current recommendations indicate that a range of at least 1.2 to 1.6 grams of protein per kilogram of bodyweight is the ideal target for health outcomes in adults to eat per day, and spreading this across the day by eating protein in each meal. Consuming enough protein is essential for building and maintaining muscle mass. This is especially important for athletes because strength training causes micro tears in muscles, and gains in strength and size are made as the muscle tissue is repaired. Without adequate protein this process cannot happen.

Ideal protein sources would come from lean meat including chicken and fish, other animal products including eggs and Greek yogurt, and complete protein plant source including quinoa, hempseed and soybeans. Many plants offer incomplete proteins but can be combined to include all the amino acids. Some of these combinations are nuts/seeds and whole grains, beans and rice, peas and pasta.

Carbohydrates

Mostly function as our bodies short term energy source. Carbohydrates are digested and turned into glucose and transported around the body as fuel. Much of this fuel is used to keep us warm, much more than exercise daily. For athletes carbohydrates are critical fuel for training and competition. Refueling the body during and after is imperative for them to be ready to work the following day. Carbs are also important because they spare protein and fat for other uses when energy is needed. If there are no carbs available for energy production the body will turn to breaking down muscle tissue for an energy source.

Many people think of carbs as evil things that cause weight gain, and that carbs only come from bread, pasta, or beer. Both of those statements are false. True, too many carbs can cause weight gain, but that is true of all food types and our bodies store extra consumed calories as adipose tissue around the body for use in the future. Most plant-based food are carbohydrates as well. Kale is a carb. Apples are carbs. Most food contains at least some amount of carbohydrate including animal products like milk.

Carbohydrates are often divided into three groups: Simple sugars, complex carbohydrates, and fiber.

Simple Carbs, sometimes called simple sugars, including glucose, maltose, fructose, and lactose.

Simple Sugar	Example Food source (there are many unlisted examples)
Glucose	Raisins and Honey
Maltose	Wheat and Barley
Fructose	Fruit and Fruit Juice
Lactose	Milk and Cheese

These carbohydrates are quick to be digested. With quick digestion comes quick energy, and our bodies love simple carbohydrates. While simple sugars are a part of daily life and the human body readily uses them for a supply of quick energy, over consumption of simple carbohydrates leads to weight gain and Type 2 Diabetes.

There is an artificial simple carbohydrate called High Fructose Corn Syrup, which is created by converting some of the glucose into fructose in corn syrup. High fructose corn syrup is a common additive in processed foods and sweets. There is some debate on if high fructose corn syrup is unhealthy, increasing the risk of heart disease, metabolic syndrome, and fatty liver disease. Research results are mixed, but it is probably best to limit processed food intake in general.

Complex Carbohydrates: These food groups are still primarily needed for energy but take longer to breakdown during digestion. They are named, as their molecular composition is more complex with long chains of sugar molecules. These foods usually provoke less of a blood sugar spike and can keep someone feeling full for longer. Some examples of complex carbohydrates are whole grains, beans, lentils, and vegetables like broccoli. These energy sources are generally believed to be the healthier option.

Fiber: We as humans can not break down and digest everything we eat, some of the non-digestible “roughage” in carbohydrates is known as fiber. Consuming adequate amounts of high fiber foods including green leafy vegetables and complex carbohydrates is important for gastrointestinal health. Fiber inherently has 0 calories so it can be used to regulate body weight and it keeps people regular with bowel movements.

Fat/Lipids

Fats (aka lipids or adipose tissue) are the most vilified of the macros because fat is seen as bad and unhealthy. The truth is that fat is critical to life. Humans need fat tissue to pad their internal organs, help with thermoregulation, and hormone production. Much more information on healthy body fat levels was covered in Chapter 2.

Nutritional levels fat helps with the feeling of satiety or feeling full after eating. It is also used as long-term energy storage on the body.

Saturated and unsaturated fats differ in their chemical structure and have different effects on health. Most oils contain higher amounts of unsaturated fats, which can help reduce the risk of heart disease and stroke. Monounsaturated fats can also help regulate blood cholesterol levels and promote normal cell development and healthy skin.

Monounsaturated fats are mainly found in plant oils, such as extra virgin olive oil, avocado, nuts (such as almonds, cashews, pecans, peanuts, and walnuts), sesame oil, high oleic safflower oil, sunflower oil, and canola oil.
Polyunsaturated fats are mainly found in plant-based foods, oils, and fish, such as nuts (like walnuts, hazelnuts, pecans, almonds, and peanuts), soybean oil, corn oil, safflower oil, flaxseed oil, canola oil, and fatty fish (such as trout, herring, and salmon). On the other hand, saturated fat is found in animal products, dairy products, palm and coconut oils, and cocoa butter. It is recommended to limit the consumption of saturated fat to less than 10 percent of your overall dietary fat intake. High levels of saturated fat in the diet are associated with increased cholesterol levels, which can lead to an increased risk of heart disease and other health issues. It is important to avoid or at least limit the consumption of saturated fat.

Omega-3 fatty acids, a type of polyunsaturated fats also called alpha-linolenic acid, are crucial for cell growth and overall health. These fatty acids have additional benefits for heart health, with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) being the two most common types found in fatty fish like salmon, sardines, and herring. Other sources of omega-3s include flaxseeds, walnuts, soybean oil, and chia seeds. It's recommended that an individual's diet should include 0.6 – 1.2% of total calories from omega-3 fatty acids each day. Studies show that consuming at least two servings of EPA and DHA per week can help reduce the risk of cardiovascular disease.

Cholesterol, an essential component of the cell membrane, is primarily synthesized by the body for various functions, such as Vitamin D synthesis, bile salts, and reproductive hormones. Although minimal cholesterol intake occurs through certain foods like animal sources, cheese, or egg yolks, unhealthy eating habits, lack of physical activity, and smoking can increase cholesterol build-up, leading to various coronary artery disease complications. High levels of cholesterol contribute to the build-up of plaque, which can further result in artery blockages.
The liver produces lipoproteins, including low-density lipoprotein (LDL) and high-density lipoprotein (HDL), that assist in transporting fat and cholesterol throughout the bloodstream. While LDL, also known as "bad" cholesterol, contributes to arterial plaque build-up, HDL, also known as "good" cholesterol, aids in removing cholesterol and returning it to the liver.

Water

The unofficial fourth macronutrient, water, is vital to all life on earth. Our bodies are about 60% water, and most of the chemical reactions keeping you alive are done in an aqueous environment. Water also helps eliminate waste products through urine and bowel movements. It even helps keep our joints lubricated for movement.

As a kinesiologist one of the most important functions of water for us to focus on is the thermoregulation sweating provides humans during activity and exercise. As we move and exercise our core body temperature rises and we naturally sweat to help remove excess heat. The loss of water through sweat can lead to dehydration, muscle cramping and heat exhaustion. Water and electrolytes need to be replaced during and after exercise to fully recover. Electrolytes are minerals in your body that are important for muscular contraction. Dehydration and lack of electrolytes can lead to muscle cramping during long or strenuous exercise.

The amount of water a person needs to drink each day depends on body size and activity level but between 0.5-1.0 ounces of water per pound body weight, increasing that amount with physical activity.

Critical Thinking

What does your daily food intake look like? How could it be improved? Compare this to Tour de France Cyclists. What is similar? What is the difference? Why?

Micronutrients

Micronutrients may get less of a spotlight in diet and nutrition, or lumped all together in one category, but they are also critical for optimal health and recovery. As the name suggests micronutrients are needed in much smaller amounts compared to macro nutrients. Micronutrients can be broken down into vitamins (including antioxidants) and minerals.

Vitamins can be subclassified into water soluble or fat-soluble vitamins. There are nine water soluble vitamins which are not stored in the body and eleven fat soluble vitamins which are stored in the body.

Minerals are inorganic substances like calcium and iron that humans use for a wide variety of crucial functions to life. Minerals are needed in small amounts, and only available from food intake.

Most healthy adults can ingest adequate amounts of micronutrients from eating a wide variety of fresh foods in a range of different colors.

Reading and understanding food labels is very important for knowing what calories, macros, and micro nutrients are in the food. Here is an interactive link to learn more.

The Nutrition Labeling and Education Act has made it mandatory for food items sold in the United States to feature a Nutrition Facts panel. This panel provides accurate information about the nutrients present in the food. It includes details such as the number of servings per container, calories per serving, and important micronutrients such as Vitamin D, Calcium, Iron, and potassium. This labeling is crucial as it helps individuals to compare different products and make informed choices about their food consumption. The Nutrition Facts panel contains information on both macronutrients and micronutrients, making it an essential tool for evaluating a food item's nutritional value. By analyzing the serving size and the nutrient content, one can make better decisions about what to consume. For example, a seemingly healthy snack like a bag of mixed nuts may contain multiple servings, and it is important to check the label for the total calorie, fat, protein, carbohydrate, vitamin, and sodium content.
The percent DV (daily value) listed on the label helps individuals determine if a food item is a good or poor source of nutrients. It reflects the nutrient's percentage in the food concerning its recommended daily intake. Therefore, it is essential to understand how to read the label to make informed decisions about one's diet.

The order of ingredients in a product's list is based on weight, with the heaviest ingredient being listed first. In the United States, manufacturers are required by law to indicate any potential allergens in the ingredient list, either in parentheses or after the list. Foods that have a lot of unfamiliar ingredients are often highly processed and contain preservatives and additives. These are added to extend the food's shelf life and improve its texture, color, or other properties. Highly processed foods tend to have fewer nutrients, so it's recommended to choose foods with recognizable ingredients whenever possible.

Dietary supplements are readily available in the United States, and are defined as products intended to supplement the diet and contain one or more dietary ingredients, such as vitamins, minerals, herbs, amino acids, or other substances. The Dietary Supplement Health and Education Act (DSHEA) of 1994 regulates the marketing and sale of supplements, but under different regulations than those governing conventional foods and drugs. Supplements come in various forms, including tablets, capsules, powders, and liquids. The FDA is only responsible for ensuring the safety of supplements that contain new ingredients, not their effectiveness, which is the responsibility of the manufacturer to test. It is important to be aware of the potential risks and benefits of using supplements, and to consult with a healthcare provider before taking any new supplements.

If a person is eating a healthy, well varied diet, they likely do not need to take supplements.

As a kinesiologist of any field, you will be asked many questions about nutrition. Many people are misinformed about what healthy eating is like or have never been taught. Altering their eating habits is one of the easiest and most effective ways people can improve their health. Here are a few topics that often come up in conversations.

Nutrient timing refers to the specific timing and distribution of macronutrients (carbohydrates, protein, and fat) in relation to exercise. Proper nutrient timing after working out might be beneficial for optimal recovery and muscle growth, but not as important as many people stress if overall proper nutrition is consistent.

Carbohydrates are the primary fuel source for high-intensity exercise, and consuming carbohydrates after working out can help replenish glycogen stores that were depleted during exercise. Protein is also important for muscle repair and growth. Consuming protein after working out can help promote muscle protein synthesis and aid in muscle recovery.
Some experts recommend consuming carbohydrates and protein within 30 minutes to an hour after exercise to maximize recovery and muscle growth. However, the specific timing and distribution of macronutrients may vary depending on individual goals and needs. It is also important to consider overall daily nutrient intake and to choose nutrient-dense, whole foods to support overall health and wellness.

Fasted Cardio is cardiovascular exercise that is performed on an empty stomach, typically in the morning before eating. The theory behind fasted cardio is that by exercising in a fasted state, the body will use stored fat as the primary source of energy, which can lead to greater fat loss.
However, the evidence on the effectiveness of fasted cardio for fat loss is mixed.

Macro percentages: there are many thoughts about how much protein, carbohydrates and fat people should be eaten each day to reach their goals. These are discussed as macronutrient percentages, or “macros''. There is no one size fits all solution to this problem. Each person’s starting body composition and activity level is different, with different goals, different genetics, and different foods they like. Individual experimentation is really the only way to find what works for each person.

A good place to start is to hit protein goals of at least 1.2 to 1.6 grams of protein per kilogram of bodyweight. Then eat enough carbohydrates that a person feels energized for their day-to-day activities and workout program, and finish with a bit of fat for satiety and flavor.

Dietary Guidelines for Americans 2020-2025 suggest the following ranges for macronutrient intake based on a person's calorie needs:

• Carbohydrates: 45-65% of daily calories
• Protein: 10-35% of daily calories
• Fat: 20-35% of daily calories

The best nutrition guide is to eat a wide variety of minimally processed fresh foods in a wide range of colors.

If you are interested in furthering your nutritional education leading to a career as a registered dietitian, you should start by looking for a Nutritional Science/Dietitian bachelor’s program.

Without being a registered dietitian, you cannot prescribe a precise diet. Do not overstep your role.

In Chapter 5 we will explore human anatomy.