The Importance of Diet and Nutrition: Why Nutrition Matters

Reviewed by: HU Medical Review Board | Last reviewed: May 2023

Nutrition plays a fundamental role in our overall health and well-being. The food we eat provides us with essential nutrients, vitamins, and minerals that our bodies need to function well. A healthy diet is crucial for all people, no matter their age or background. It can have a profound impact on physical and mental well-being.1-5

Nutrition basics

Nutrition is the process by which our bodies get the necessary nutrients for growth, maintenance, and repair. Nutrients give our bodies nourishment and support the growth and repair of our tissues. There are 2 main types of nutrients: macronutrients and micronutrients. Together, they help our bodies function properly.1


Macronutrients include carbohydrates, proteins, and fats. These are the main nutrients we get from our food.1

Carbohydrates (carbs) are the main source of energy for our bodies. They are found in foods such as grains (bread, pasta, rice), fruits, and vegetables. Carbs contain 4 calories per gram. It is healthier to choose complex carbs, like whole grains, over simple carbs, like white bread. Complex carbs contain more fiber and help you feel fuller longer.1

Proteins are vital for the growth and repair of muscles, tissues, and organs. They support the immune system and produce enzymes and hormones. Good sources of protein include lean meats, fish, poultry, legumes, and dairy products. Proteins contain 4 calories per gram.1

Fats provide energy, insulation, and protection to the body. They can be found in foods like nuts and seeds, oils, butter, and dairy products. Fats contain 9 calories per gram. But some fats are healthier than others. Healthy fats include nuts, seeds, avocados, and olive oil.1

According to the Dietary Guidelines for Americans, a healthy diet should consist of:1

  • 45 to 65 percent of calories from carbs
  • 20 to 35 percent of calories from fats
  • 10 to 35 percent of calories from proteins


Micronutrients are vitamins and minerals. They help maintain good digestion and brain function, build strong bones and teeth, and boost the immune system. A balanced diet that includes a variety of fruits, vegetables, whole grains, and lean proteins gives you the vitamins you need to be healthy.1

Examples of vitamins and the foods that contain them include:1

  • Thiamine (vitamin B1) – white rice, fortified cereals, black beans
  • Riboflavin (vitamin B2) – oats, milk, fat-free yogurt
  • Niacin (vitamin B3) – chicken, turkey, tuna
  • Biotin (vitamin B7) – eggs, salmon, sweet potatoes
  • Folate (vitamin B9) – spinach, white rice, asparagus
  • Cobalamin (vitamin B12) – fish, meat, dairy
  • Ascorbic acid (vitamin C) – red peppers, citrus fruits, kiwis

Examples of minerals and the foods that contain them include:1

  • Calcium – dairy products, orange juice, yogurt
  • Magnesium – nuts, seeds, spinach
  • Sodium – salty foods
  • Potassium – bananas, prunes, lentils

Why eat a balanced diet?

Eating a nutritious diet can help you manage existing health conditions and improve your overall quality of life. A healthy diet can also help you maintain a healthy weight. And it can greatly reduce your risk of developing health conditions such as:2-5

  • Heart disease
  • Diabetes
  • Obesity
  • Certain types of cancer

A healthy diet also supports growth and development in children and adolescents. Nutrients from a varied diet help with bone development, brain function, and immune system support. A diet lacking in nutrients can stunt physical and mental development.2-5

Beyond physical health, nutrition also plays a crucial role in psychological well-being. Several studies have shown a strong link between diet and mental health.6

Eating a diet high in fruits, vegetables, whole grains, and lean proteins has been linked to a reduced risk of depression, anxiety, and other mental health disorders. On the other hand, a diet high in processed foods, sugar, and unhealthy fats has been linked to an increased risk of mental health problems.6

What does a balanced diet consist of?

A well-balanced diet includes a variety of fruits, vegetables, whole grains, and lean proteins. This ensures that the body gets all the necessary nutrients. Staying hydrated by drinking plenty of water is also essential for good health.3

Strive to eat a nutrient-dense diet. This means that the foods you eat most of the time are packed with lots of vitamins and minerals to give your body the support it needs to function well.5

Examples of nutrient-dense foods are:5

  • High-fiber fruits and vegetables
  • Leafy greens
  • Cruciferous vegetables (broccoli, cauliflower, Brussels sprouts)
  • Starchy vegetables like potatoes, yams, and corn
  • Whole grain bread and pasta
  • Beans, peas, and lentils
  • Lean meats (fish, turkey, chicken)
  • Nuts and seeds
  • Low-fat dairy products

Unfortunately, many people base their diet on highly processed foods, fast foods, and snacks that are high in sugar, salt, and fat. These nutrient-poor foods are often more readily available and cheaper than healthier, nutrient-dense alternatives.4

Busy lifestyles and convenience have also contributed to a shift toward eating high-calorie fast foods and ultra-processed meals. In fact, fewer than 1 in 10 children and adults eat the recommended daily amount of vegetables. As a result, malnutrition and diet-related chronic diseases have become a global health concern. But it is possible to eat well on a budget.4,5

Seek help from a dietitian or nutritionist

Dietitians and nutritionists are experts in food and nutrition. They help people make balanced meal plans that work for their life and budget. If you are interested in meeting with one of these professionals, ask your doctor for a recommendation.

Proper nutrition provides the body with the necessary nutrients to thrive, maintain good health, and prevent chronic diseases. When you eat a balanced diet, it can support your growth and development, enhance your mental well-being, and improve your overall quality of life.

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