Nutrition Basics

What are the basics of nutrition? What should nutrition look like for health? How can you avoid poor nutrition?

Learn to be more mindful about your eating after reading this extensive guide. Grab a cup of coffee, might take a sec.

Nutrition Basics

Nutrition is a complex science.

Health, mood, body composition, and performance are all influenced by what you eat and drink regularly.

The food choices you make daily have both long and short term impacts on your health.

There are no good or bad foods. A better question might be good for what?

  • "Good habits" are actions that support your current goals and values.
  • A "bad habit" does not align with your current goals and values.

While there are no good and bad foods, food choice does matter.

By reading this guide you should learn a lot about how to eat a diet filled with a wide variety of nutritious foods. This article is meant to be a hub that I will build concepts and ideas out from. Let me know if anything seems confusing or could be improved.

Sliced white mushrooms, carrots and radishes in a silver, metal pot

Summary of Nutrition Basics (TLDR)

  • If you have particular nutritional needs, contact a Registered Dietitian - While most of us meet our needs with general advice, Registered Dietitians like the team at Bamboo Nutrition are the doctors of food.
  • "Good Nutrition" isn't common sense - Nutrition studies the science of food and its interactions within the body. Also taken into consideration are the social, cultural, economic, and psychological effects of food.
  • Nutrition is important because it affects our short and long-term health - In most meals, you need to include a wide variety of foods to meet your needs. No, there aren't "bad foods".
  • There are six classes of nutrients - Carbohydrates, fats, protein, water, vitamins, and minerals. Carbs, fats, and proteins provide energy.
  • Poor nutrition is caused by chronic deficiencies and a lack of variety - While you don't need every nutrient at each meal, your daily choices add up.
  • Signs of poor nutrition vary - Night blindness, hair loss, and skin rashes can all stem from a lack of different nutrients.
  • We can improve nutrition by following the six diet planning principles - The Dietary Guidelines for Americans turn numbers and recommendations into foods.

This article will answer the following questions and more:

  • What is Nutrition?
  • Why is nutrition important?
  • What are the basics of nutrition?
  • What are different types of nutrients?
  • What foods are the highest in protein?
  • What is the most important nutrient?
  • What are the energy giving foods?
  • What defines good nutrition?
  • How can we improve nutrition?
  • What causes poor nutrition?
  • What is a sign of poor nutrition?

What is Nutrition?

Nutrition is a science that studies behavior, food, and how the human body processes it. Not only is the study of nutrition about what we eat, it considers why we eat what we do.

Food choices are influenced by¹;

  • Preferences - What tastes do you prefer? Sweet? Spicy?
  • Habit - Do you eat the same thing every morning for breakfast?
  • Ethnic Heritage and Regional Cuisines - What regional and ethnic foods did you grow up eating?
  • Social Interactions - What do you go out to eat with friends and family?
  • Availability, Convenience, and Economy - What can you afford? What's accessible? Quick?
  • Positive and Negative Associations - Do you relate foods with feelings?
  • Emotions - What is your mood like when you eat? Are you looking for comfort?
  • Values - Do you make food choices with religious, political, or economical concerns?
  • Bodyweight and Image - Do you select foods based on how you believe they'll impact your appearance? Performance?
  • Nutrition and Health Benefits - Do you eat foods because you believe they'll improve your health?

We all have different motivations for our choices. What I grew up eating in Chicago is different from what you'll find in Columbia, Missouri. Ketchup doesn't go on hotdogs.

If food choice is limited in your neighborhood, it makes it difficult to vary your diet.

Now that we know more about why we eat the way we do, let's talk more about how our choices impact us long-term.

Why is Nutrition Important?

Nutrition is important because what we eat and drink has an impact on our long-term health and mood.

Our bodies are made of compounds that are very similar to those we find in foods. Foods provide nutrients. Nutrients support our growth, recovery from exercise, and immune system function.

Some nutrients contain energy. Other nutrients provide structural materials and regulating agents that aid in maintaining life.

Some of these nutrients are essential. Essential means that it’s needed and that it has to come from outside the body.

Note: Foods do contain other compounds such as phytochemicals, additives, and alcohols. For this article, we will not be discussing those.

Personal Trainers may provide general nutrition information. As a Precision Nutrition certified professional, I cannot practice dietetics, medical nutrition therapy, or provide any medical advice.

If you have more intense nutritional needs, contact a Registered Dietitian. A dietitian with a background in sports nutrition would be nice to have.

For a more detailed look at nutrition basics, read on.

Let's talk about the basics of nutrition.

What are the Basics of Nutrition?

The basics of nutrition combine your favorite foods with a nutritionally balanced diet.

Not to be confused with weight loss, diet refers to the foods that we eat and drink regularly.

The type of diet you're on depends on the variety, amount, and even the timing of the foods you eat². There are numerous diets out there.

For example:

  • Food elimination diets
  • Heart healthy diets
  • High protein diets
  • Intermittent Fasting
  • Low carbohydrate diets
  • Low energy diets (800-1200 calories per day)
  • Low fat diets
  • Mediterranean diet
  • Vegetarian diets
  • Vegan diets
  • Paleo
  • Weight loss diets

By no means is the above an exhaustive list. Good nutrition supports good health and supplies you with all the nutrients you need.

What are Different Types of Nutrients?

Foods contain six different types or classes of nutrients¹:

  1. Minerals
  2. Water
  3. Carbohydrate
  4. Fat
  5. Protein
  6. Vitamins

Macronutrients are nutrients needed in large amounts daily.

Micronutrients are nutrients needed in small amounts daily.

Carbohydrates, protein, and, fat are macronutrients. Vitamins and minerals are micronutrients. Water is essential in all life processes.

Protein, carbohydrate, fat, and vitamins are organic nutrients, meaning they contain carbon. Water and minerals are inorganic nutrients. Besides vitamins, organic nutrients contain energy. Vitamins help us use the energy in our food and take part in other actions in the body.


Minerals are the simplest elements contained in your body. Minerals are made up of one element such as iron, sodium, or potassium. Although they do not contain energy, minerals are an important part of a balanced diet.

Minerals are essential for many functions in the body including:

  • Bone growth
  • Regulating hydration
  • DNA maintenance and replication
  • Metabolism

Minerals sort into two equally important groups by the amount needed, major and trace;

  • Major Minerals or macrominerals are required in larger amounts (>100 milligrams per day).
  • Trace Minerals or microminerals are required in smaller amounts (<100 milligrams per day).

Remember the concept of essential from above?

The 16 Essential Minerals for Health include¹:

  1. Calcium
  2. Potassium
  3. Sodium
  4. Phosphorus
  5. Chloride
  6. Magnesium
  7. Sulfate
  8. Iron
  9. Iodide
  10. Zinc
  11. Chromium
  12. Selenium
  13. Fluoride
  14. Molybdenum
  15. Copper
  16. Manganese

(1-7 are major minerals, 8-16 are the minor minerals.)

Minerals not on this list can become conditionally essential. A conditionally essential nutrient becomes essential because the body cannot make enough of it under certain conditions.

Mineral recommendations can vary based on sex, activity level, and life stage.


You can't live without water. Water is the most abundant and second simplest element found in the body. Up to 60% of the adult body is made up of water¹.

Water plays a role in all life processes including:

  • Body temperature regulation - excess heat is lost through sweat evaporation.
  • Joint lubrication and cushioning.
  • Transportation of nutrients and waste throughout the body.
  • Serving as a solvent for minerals, vitamins, and other compounds making them accessible to the body.

Our bodies attempt to keep us in water-balance.

  • We lose water by sweating, breathing, peeing, and pooping. If water loss exceeds balance, you feel hunger and thirst.
  • When water intake exceeds balance, your stomach expands. Stretch receptors tell us to stop drinking.

Foods and drinks contain varying amounts of water:

Water Content Range for Selected Foods³:

Food Item Percentage
Water 100%
Fat-free milk, watermelon, spinach 90–99%
Fruit juice, yogurt, carrots 80–89%
Bananas, avocados, shrimp 70–79%
Pasta, ice cream, chicken breast 60–69%
Ground beef, hot dogs, feta cheese 50–59%
Pizza 40–49%
Cheddar cheese, bagels, bread 30–39%
Pepperoni sausage, cake, biscuits 20–29%
Butter, margarine, raisins 10–19%
Walnuts, cereals, peanut butter 1–9%
Oils, sugars 0%

(Popkin, D'anci, & Rosenberg, 2010)

The amount of water that you need is influenced by;

  • Diet
  • Activity
  • Environmental temperature
  • Humidity
  • Sweat rate

Because water needs vary so much, recommendations for intake are difficult to establish.


Dietary carbohydrates or carbs include sugars, starches, and fibers.

Carbohydrates are made of oxygen, carbon, and hydrogen. They're divided into three groups of sugars based on complexity:

  • Monosaccharides or single sugars - Glucose, fructose, and, galactose.
  • Disaccharides or pairs of single sugars - Maltose, sucrose and, lactose.
  • Polysaccharides large chains of single sugars - Starches, fiber and, glycogen.

Digested in the mouth, stomach, and intestines, your brain uses carbohydrates to think. Muscles prefer to use carbohydrates as a fuel source during high-intensity exercise.

Carbohydrate is present in your body in two forms:

  1. Glucose - Carbohydrate intended for immediate use.
  2. Glycogen - Carbohydrate intended for storage.

While glucose and glycogen exist in your body, carbohydrate comes from foods like:

  • Whole Grains - Whole wheat flour, brown rice, and oatmeal.
  • Fruits - Apples, bananas, pears, watermelon, and grapes.
  • Vegetables - Broccoli, bok choy, spinach, collard greens, and chili peppers.
  • Beans and other Legumes - Kidney beans, soybeans, chickpeas, and navy beans.
  • Dairy - Milk, ice cream, cheese, and .yogurt.
  • Other Concentrated Sources - Candy, cookies, cake, soda (or pop/sodie pop).

Consuming enough carbohydrates is important for protein-sparing or avoiding using protein for energy¹. Eating fiber regularly helps keep you well, regular.


Fat or lipids consist of fatty acids, triglycerides, phospholipids, and sterols.

Like carbohydrates, fat is made of hydrogen, oxygen, and carbon. The arrangement of these atoms determines the fat type.

Relative to carbs, fat has a higher ratio of hydrogen and carbon to oxygen. Because of that, it provides much more energy.

Fat is the most abundant source of energy in the body.

In the body, fat:

  • Insulates us from the cold.
  • Protects our organs.
  • Forms our cell membranes.
  • Keeps our hormones functioning.
  • Acts as a shock absorber to protect our joints.

A well-balanced diet needs fat to store and absorb important fat-soluble vitamins, A, D, E, and K.

Fat is present in your blood and brain and stored in fat cells. Fats are digested in the mouth, stomach, and small intestines. Your body prefers to use fat as its primary fuel in low-intensity or long-duration activities. Think marathons.

The simplest units of fat are fatty acids. They're comparable to the monosaccharide in carbs.

There are two types of fatty acids:

  1. Saturated Fatty Acids - mostly animal fats.
  2. Unsaturated Fatty Acids

The more hydrogens a fatty acid contains, the more "saturated" it is.

Unsaturated Fatty Acids can be further divided into two more categories you may be familiar with:

  1. Monounsaturated fatty acids - olive oil, avocado, peanuts, and almonds.
  2. Polyunsaturated fatty acids - walnuts, soybean, sunflower, and canola oils.

Polyunsaturated, omega-6 fatty acids, and polyunsaturated, omega-3 fatty acids are considered essential to your diet. Trans-fatty acids behave like saturated fatty acids in the body.

If you join three fatty acids together, the result is a triglyceride.

The most common fats in your diet are fatty acids and triglycerides (fats and oils). Phospholipids and Sterols make up only 5% of the lipids in the diet¹.

Phospholipids are used as emulsifiers by the food industry. Emulsifiers allow the mixing of oils and fats in watery solutions like mayonnaise.

Sterols are vitally important in the body. Sterols include sex hormones, adrenal hormones, bile (digestive aid), vitamin D, and cholesterol.

Common fat sources include:

  • Avocado
  • Butter
  • Olive oil
  • Peanut oil
  • Fish oil
  • Whole Milk
  • Nuts

Saturated fats, trans fats, and cholesterol have been connected to chronic disease,. Monounsaturated and polyunsaturated fats seem to offer health benefits¹.


Protein is an important part of every cell in your body.

Protein has many roles in your body including¹:

  • Providing structure - Skin, hair, muscle, tendons, ligaments, bone, and blood are all made up of proteins.
  • Aiding chemical reactions - Proteins act as enzymes. Enzymes aid chemical reactions including breakdown, transformation, and creation of new substances in the body.
  • Regulating fluid balance - Proteins maintain fluid volume within cells and blood plasma.
  • Supplying transportation - Some proteins like hemoglobin transport nutrients and other molecules.
  • Acting as a messenger - Hormones and receptors act as a chemical messaging system. Some hormones, like insulin and growth hormone are proteins.
  • Regulating our acid-base balance - Proteins accept and release hydrogen ions. This buffers the body's pH levels.
  • Acting in our defense system - Proteins act as antibodies. Antibodies defend the body from infection, and disease, future, and present.
  • Yielding energy - If needed, your body can convert protein into glucose to supply the brain and nervous system with energy.

To form a blood clot, we need protein. To see, our eyes rely on a protein found in the retina, Opsin.

We need to go a step further when we talk about this macronutrient. Protein by itself doesn't give us the entire story. You see, proteins are chains made up of amino acids.

Carbon, hydrogen, oxygen, and nitrogen atoms form amino acids.

You don't have a protein need, more an amino acid need.

This is why you hear people talking about eating "complete sources of protein". Complete proteins contain enough of the essential amino acids to meet your needs.

(It's just easier to talk about protein than amino acids)

Each of the amino acids has the same basic structure but differ in side groups or side chains. This makes proteins much more complicated than carbohydrates or fats.

To be exact, there are about 21 common amino acids, each containing a unique side chain.

Like above, we separate amino acids into groups. The ones that your body can make on its own are "Nonessential Amino Acids". "Essential Amino Acids" must be present in your diet. Your body can't create them.

The Essential Amino Acids:

  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

The Nonessential Amino Acids:

  • Alanine
  • Arginine
  • Asparagine
  • Aspartic Acid
  • Cysteine
  • Glutamic Acid
  • Glutamine
  • Glycine
  • Proline
  • Selenocysteine
  • Serine
  • Tyrosine

(Note: Some amino acids may become conditionally essential.)

A conditionally essential amino acid is one that becomes essential under specific conditions. For example, if your diet is short in phenylalanine, tyrosine becomes essential.

No protein supplements are needed. If you eat enough high-quality protein, you should meet your needs.

What foods are the highest in protein? Amino acid scoring helps us determine if foods offer the complete profile of amino acids needed. Foods are often compared to a reference protein, a whole egg, which scores highly.

The Protein Digestibility-Corrected Amino Acid Score is the current method that we use to get an amino acid score. The PDCAAS ranges from a minimum score of 0 to a maximum of 1.0

Here are the PDCAAS of Selected Food Proteins:

  • Soy Protein Isolate - 1.0
  • Whey Protein Isolate - 1.0
  • Egg White - 1.0
  • Pea Protein - 0.89
  • Peanuts - 0.52
  • Wheat Gluten - 0.25

The higher the number, the more amino acids available for your body in a food.

Sidenote on PDCAAS scoring

There are limitations to measuring protein quality using the PDCAAS. This score relies on measuring amino acids left in the feces. A new protein quality measure (digestible indispensable amino acid score; DIAAS) has been recommended to replace PDCAAS⁴.

For more on protein, read Everything You Want to Know About Protein and More.


Vitamins are essential nutrients needed in small amounts to support health and prevent deficiency. While vitamins themselves don't provide energy, they do support thousands of actions in the body.

There are 13 vitamins in all, each with their own role.

We sort vitamins into two classes based on how they dissolve:

  1. Water Soluble Vitamins
  2. Fat Soluble Vitamins

Water Soluble Vitamins

Water-soluble vitamins are found in watery parts of foods and travel freely throughout the body. Your body does not store water-soluble vitamins very long. They must be consumed regularly.

Water-Soluble Vitamins include:

  • Vitamin C
  • The B vitamins
    • Thiamin
    • Riboflavin
    • Niacin
    • Biotin
    • Pantothenic Acid
    • Folate
    • Vitamin B6
    • Vitamin B12

The B vitamins help our bodies use the energy from carbs, fats, and proteins as fuel. Folate plays an important role in synthesizing DNA for new cell growth. Vitamin C helps to form collagen.

B12 deficiency symptoms include anemia, nerve damage, and paralysis. A biotin deficiency can cause hair loss, skin rashes, and neurological disturbances.

Fat Soluble Vitamins

Fat-soluble vitamins are found in fats and oils of food and may rely on transport proteins. The body stores fat-soluble vitamins. They can be eaten in larger amounts less frequently than water-soluble vitamins.

The Fat-Soluble are:

  • Vitamin A
  • Vitamin D
  • Vitamin E
  • Vitamin K

Vitamin A helps you see. Vitamin D is needed for bone growth. Vitamin E may help prevent heart disease.

Vitamin A deficiencies result in night blindness, total blindness (xerophthalmia), and increased risk of contracting an infectious disease. Low consumption of vitamin D can lead to rickets, osteomalacia, and osteoporosis. A lack of vitamin K can reduce your blood's ability to clot.

More on Vitamins:

  • Bioavailability is an estimate of the number of vitamins available in a food that can be absorbed by your body. Bioavailability is influenced by several factors. Processing foods can dramatically change their bioavailability. The way you store and prepare your meals can impact vitamin absorption.
  • The function of each vitamin depends on the presence of another. Vitamin deficiency does not occur in isolation. For example, vitamin E deficiency can undermine your body's ability to store and absorb vitamin A.
  • Excessive intake of vitamins can be toxic. A vitamin can be both essential and toxic in large doses. Even water-soluble vitamins can be consumed in excess.
  • The solubility of vitamins affects how our body deals with their excess. Water soluble vitamins are more easily excreted by our kidneys. Excess fat soluble vitamins tend to remain in fat storage sites and are not as easily discarded.

Different foods within food groups contain different vitamins. Variety influences your ability to meet your body's requirements.

Talk to your doctor or health care professional before seeking out vitamin supplements.

A balanced diet usually meets your vitamin needs. Healthy people can support overall health by following the Dietary Guidelines for Americans.

What is the Most Important Nutrient?

The most important nutrient in the body is water. Water is the most abundant chemical substance in the body. You can make it weeks without some nutrients but, you can only survive a few days without water.

For more information on water, see the section above.

What are the Energy Giving Foods?

Foods that include carbohydrates, fats, and proteins contain energy. When we eat them, foods release that energy for use in our bodies.

Kilocalories, or calories, are the units that scientists use to express the energy each food supplies;

  • Carbohydrates contain 4 calories per gram.
  • Protein contains 4 calories per gram.
  • Fat contains 9 calories per gram.

While alcohol is included at 7 calories per gram, we don't consider it a nutrient. It interferes with the body's development, maintenance, and restoration¹.

What Defines Good Nutrition?

Good nutrition considers your tastes, preferences, and essential needs to provide a balanced diet.

In truth, "good nutrition" is a moving target that depends on your age, sex, and lifestyle. Nutrition changes during infancy, late childhood, and adulthood.

Age-related decline and illness may impair your body's ability to process nutrients. Pregnancy comes with its unique challenges for women. These are cases where a good Registered Dietitian can help.

What we know about food is constantly evolving.

Some foods are known as "functional foods". Functional foods provide health benefits beyond their nutritional content.

Examples of functional foods include⁵:

  • Conventional foods - Grains, fruits, vegetables, and nuts.
  • Modified foods - Yogurt, cereals, and orange juice.
  • Cold-Water Fish - Sardines and Salmon.
  • Beans - Without salt added if canned.

Thousands of research studies have boiled down what we need for good nutrition into recommendations called Dietary Reference Intakes (DRI).

Dietary Reference Intakes establish the boundaries for nutrient recommendations for healthy people.

How Can We Improve Nutrition?

You can improve your nutrition by following the six diet planning principles¹:

  1. Adequacy
  2. Balance
  3. Calorie Control
  4. Nutrient Density
  5. Moderation
  6. Variety

Adequacy is providing you with all the fiber, nutrients, and energy needed for health.

Balance is finding room for foods rich in some nutrients without compromising foods that are rich in others. For example, rice protein is limited by the essential amino acid, lysine⁶. If you want to meet your need for lysine, you'll have to leave room for a food high in it, beans.

(Eat your vegetables)

Calorie control involves balancing intake with the amount of energy your body needs. Offsetting balance, in this case, leads to weight gain or weight loss.

Considering nutrient density entails selecting foods that provide the most nutrients for the least calories per serving. You're considering adequacy and energy balance at the same time.

If a food provides fewer nutrients per calorie, it is said to be energy-dense. Energy-dense foods with few nutrients are called "empty calorie" foods.

Moderation factors for enjoyment. Fatty and sugary foods often provide bliss but, few nutrients. Moderation involves eating highly palatable foods, occasionally. Improved nutrient density is a side effect of moderation.

Variety is about selecting different foods from each of the food groups. Each food group is different. Each food within a food group has its own nutrient profile. Variety can help you avoid boredom while meeting nutritional adequacy.

Each of the six diet principles is interrelated. Balanced meals incorporate a variety of wholesome foods and supply a variety of nutrients.

What Causes Poor Nutrition? What is a Sign of Poor Nutrition?

Depending on the deficiency, poor nutrition can show up with a wide variety of symptoms.

Here are some examples of symptoms associated with nutrient deficiencies in major minerals¹:

  • Sodium - Muscle cramps, mental apathy, loss of appetite.
  • Potassium - Irregular heartbeat, muscular weakness, glucose intolerance.
  • Calcium - Stunted growth in children and bone loss (osteoporosis) in adults.
  • Phosphorus - Muscular weakness and bone pain.

Poor nutrition can be caused by many factors including skipping one of the six diet planning principles.

For a full breakdown of individual foods, checkout Food Data Central⁷.


  1. Whitney, E., Pinna, K., & Rolfes, S. R. (2015). An Overview of Nutrition. In Understanding Normal and Clinical Nutrition (10th ed., pp. 3-33, 129-190, 367-396). Stamford Place, CT: Cengage Learning.
  2. Aragon, A. A., Schoenfeld, B. J., Wildman, R., Kleiner, S., Vandusseldorp, T., Taylor, L., . . . Antonio, J. (2017). International society of sports nutrition position stand: Diets and body composition. Journal of the International Society of Sports Nutrition, 14(1). doi:10.1186/s12970-017-0174-y
  3. Popkin, B. M., D'anci, K. E., & Rosenberg, I. H. (2010). Water, hydration, and health. Nutrition Reviews, 68(8), 439-458. doi:10.1111/j.1753-4887.2010.00304.x Table 1
  4. Leser, S. (2013). The 2013 FAO report on dietary protein quality evaluation in human nutrition: Recommendations and implications. Nutrition Bulletin, 38(4), 421-428. doi:10.1111/nbu.12063
  5. Klemm, R. (2019, July 15). Functional Foods. Retrieved July 15, 2020, from
  6. Phillips, S.M. The impact of protein quality on the promotion of resistance exercise-induced changes in muscle mass. Nutr Metab (Lond) 13, 64 (2016).
  7. U.S. Department of Agriculture, Agricultural Research Service. FoodData Central, 2019.

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Steven Mack is founder and a Certified Strength and Conditioning Specialist at the private training studio, Simple Solutions Fitness. He consults for Stronger by Science, a leader in fitness research dissemination, and is a former Mizzou football walk-on. Steven dedicates his professional life to helping people through his writing, speaking, and role as a personal trainer.