What is Nutrition and Why Does it Matter?

A variety of nutritious foods
A variety of nutritious foods.

JeniFoto/Getty Images

Nutrition plays a role in keeping us healthy throughout our lives. The foods we eat provide nutrients that the body needs each day. Studies show that a poor diet can contribute to an increased risk of heart disease, cancer, cognitive decline, and depression; focusing on a balanced nutrient-dense diet can help individuals prevent health conditions later in their life.

A registered dietitian breaks down proper nutrition and why it's so important to your overall well-being.

What Is Nutrition?

The Collins dictionary defines nutrition as "the process of taking food into the body and absorbing the nutrients in those foods."

Basically, we need nutrients from food to survive and thrive. While food is certainly meant to be enjoyed, it's about more than just taste and pleasure. Food provides the nutrients that our body needs for everything it does, including digestion, breathing, thinking, and providing energy for all movement.

You can think of nutrition as a three-part process:

  1. We consume foods and beverages.
  2. Digestion breaks foods and beverages down into nutrients, including vitamins and minerals.
  3. The nutrients travel through the bloodstream and reach different parts of the body, where they are needed for different processes, such as sustaining muscle, hormone, and bone health.

Understanding the Key Components of Nutrition

The food we eat contains nutrients that the body needs daily. Here's how the key components of food play a role in our overall health.


Macro means "big." Macronutrients are required in large amounts because they provide energy (calories) to the body, and serve many other vital functions:


Starch, sugars, and fiber are types of carbohydrates. Starch and sugar are broken down into glucose, the main source of energy for your body's cells, tissues, and organs. Fiber does not break down to glucose. Instead, fiber helps prevent constipation, provides fullness, and may help lower cholesterol and blood sugar levels.


Fats provide energy and help the body absorb vitamins. Fats also cushion and protect organs, help keep the body warm, and help make hormones. Opt for unsaturated fat instead of saturated or trans fat most often.


Our bodies need protein for every cell, and to maintain bones, muscles, and skin.

You can get enough macronutrients by creating balanced meals. Fill half your plate with vegetables and fruit (carbs and fiber), a quarter of your plate with whole grains (carbs, fiber, and protein), and the remaining quarter with protein-rich foods such as beans, dairy, tofu, chicken, fish, eggs, or meat (protein and fats). Choose food sources with healthy fats such as olive oil, nuts, and seeds, too.

The amount of carbohydrate, protein, and fat you need depends on your age, sex, medical conditions, activity level, and dietary goals. Work with a registered dietitian to focus on your personal nutrition goals.


Micro means small. Micronutrients are the nutrients that we need in smaller amounts, such as vitamins and minerals.


There are 13 essential vitamins that we need to get from food and beverages: vitamins A, C, D, E, K, and the B vitamins (B1, B2, B3, pantothenic acid, biotin, B6, B12, and folate). Here's an example of why we need some of these nutrients:

  • Vitamin A is important for normal vision and the normal functioning of the immune system.
  • Vitamin B2 helps turn food into the energy you need, and is important for the growth and development of body cells.
  • Vitamin D helps maintain strong bones, helps muscles move, and helps nerves carry messages between the brain and body.


Many minerals are essential for health, including calcium, phosphorus, potassium, sodium, chloride, magnesium, iron, zinc, manganese, and selenium. They all play different roles. For example:

  • Calcium helps muscles contract and expand, helps release hormones and enzymes for many body processes, and is required for healthy bones.
  • Iron helps transport oxygen from the lungs to the tissues and muscles.

The amount of vitamins and minerals you require each day depends on your age, sex, and medical conditions. Work with a dietitian to learn more.

By following the Dietary Guidelines for Americans, you will likely get enough vitamins and minerals from foods and beverages. In some cases, when you can't get enough of these vitamins or minerals through foods, a supplement may be required.


Another nutrient we require daily is water. It makes up more than two-thirds of human body weight and is required for all of the body's cells and organs.

The Dietary Reference Intake for water is between 91 and 125 fluid ounces (2.7 to 3.7 liters) per day, but individual needs vary depending on weight, age, activity level, and medical conditions.

Benefits of Proper Nutrition

People who eat a balanced diet and get the nutrients that their body requires tend to live longer and have a lower risk of developing chronic diseases. Proper nutrition can also reduce the risk of mental illness, including depression.

For people with chronic diseases, healthy eating can help manage their conditions and prevent complications.

Studies show that a balanced eating plan, such as MyPlate, the Mediterranean Diet, MIND Diet, or DASH diet, can help reduce the risk of cancer, heart disease, type 2 diabetes, cognitive decline, and mental illness.

Consequences of Poor Nutrition

The World Health Organization says that major diet-related diseases such as type 2 diabetes, heart disease, cancer, obesity, osteoporosis, and dental diseases are partly caused by unhealthy diets.

Many Americans do not follow a balanced diet and get too much sodium, saturated fat, and added sugar, and not enough vegetables. Poor nutrition increases the risk of chronic diseases, but focusing on nutrient-dense ingredients can reverse the risk.

How to Ensure Proper Nutrition in Your Life

Nutrition is a fine balance. It's easy to say "eat well!" but there are many factors to consider, including cost, food access, preferences, medical conditions, food intolerances, culinary skills, and convenience. If you are unsure about nutrition, consider seeing a registered dietitian for personalized advice.

If a private dietitian is not financially viable, you can try to access low-cost or free care through local public health offices. People with children under the age of five can access Women, Infants, and Children (WIC) services, which offers supplemental nutritious foods and nutrition counseling.

A Word From Verywell

Nutrition plays a vital role in an overall healthy lifestyle. A balanced eating plan with sufficient nutrients from vegetables, fruit, whole grains, and protein-rich foods can ward off chronic diseases and may help you live longer. If you're not sure how to plan a nourishing, balanced diet, speak with a dietitian.

Frequently Asked Questions

  • What does a balanced diet look like?

    Fill half your plate with vegetables and fruit, a quarter of your plate with whole grains, and the remaining quarter with protein-rich foods such as beans, dairy, tofu, chicken, fish, eggs, or meat (protein and fats). This will provide the nutrients that your body needs to function optimally.

  • How does good nutrition impact mood?

    Poor nutrition may cause low mood and depression, but improving diet may help protect mental health.

  • Are supplements needed for good nutrition?

    People who follow the Dietary Guidelines for Americans will likely get enough vitamins and minerals from foods and beverages. In some cases, when you can't get enough of these nutrients through foods, a supplement may be required. Check with a doctor or dietitian to know for sure.

24 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Cara Rosenbloom, RD
 Cara Rosenbloom RD is a dietitian, journalist, book author, and the founder of Words to Eat By, a nutrition communications company in Toronto, ON.