6 Essential Nutrients: Functions, Energy, Meal Ideas

Food contains a mixture of macronutrients and micronutrients essential for health throughout all phases of life. Macronutrients (those needed in large amounts) are carbohydrates, fat, protein, and water. Micronutrients (those needed in smaller amounts) include vitamins and minerals.

Every nutrient has unique functions. Deficiencies in a specific vitamin or mineral, for example, increase the risk of different types of conditions and diseases. On the other hand, excessive intake of nutrients over time can also have adverse effects.

The 6 Essential Nutrients and Their Functions

Nutrients are chemicals in food that are needed for energy, growth, and maintenance of organs, cells, skin, blood, and other body functions. An essential nutrient is something the body cannot make on its own. However, sometimes certain nutrients are considered “conditionally essential.”

Conditionally essential nutrients are needed in the diet when the body is unable to make them, such as in times of illness or stress. Nutrients the body can synthesize from other compounds but also can be derived from the diet are considered nonessential.

Carbohydrates

Carbohydrates are molecules that can be broken down into glucose and other simple sugars. They are necessary for energy to support the brain and body. Carbohydrates provide 4 calories per gram.

Carbohydrates are classified as:

• Simple carbohydrates are short-chain molecules and include monosaccharides (glucose, fructose, and galactose) and disaccharides (including sucrose, lactose, and maltose).
• Complex carbohydrates are long-chain molecules and include polysaccharides, starch, and fiber.

Simple carbohydrates include sugars found in fruits, some vegetables, dairy products, and honey, while complex carbohydrates come from starch and fiber in plants (including grains, vegetables, fruits, nuts, seeds, and legumes).

Carbohydrate sources contain varying amounts of fiber, proteins, fats, vitamins, minerals, phytochemicals, prebiotics, and anti-nutritional factors that may impact diet quality and health.

Adults need about:

• 1.5 to 2 cups of fruit daily
• 2 to 3 cups of vegetables daily
• Three to six servings of whole grains daily
• Three servings of low-fat dairy or nondairy equivalent
• One to three servings of legumes per week

Protein

Protein is another essential macronutrient that acts as the building block for muscle, bone, cartilage, and skin. It is made up of long chains of amino acids.

Protein is needed when cells are being repaired, as in wound healing, and is involved in immune functioning and carrying vitamins, minerals, and oxygen around the body. Protein provides 4 calories per gram.

Protein is found in plants, like legumes, whole grains, nuts, seeds, and vegetables. Protein is also found in animal products like eggs, cheese, milk, yogurt, meat, poultry, and fish. You may also find protein in packaged food as well as protein powders.

There are 20 main amino acids, nine are essential, some are nonessential, and others are conditionally essential. The daily Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight (g/kg). This is considered sufficient for nearly all healthy individuals.

For example, a person who weighs 150 pounds (68.2 kilograms) needs to consume 55 grams of protein per day to prevent deficiency.

Yet, some people may need more protein per kilogram. For example, needs increase for people looking to achieve athletic performance, build lean muscle mass, prevent muscle wasting, during times of illness or recovery, and in wound healing.

Fat

Fat, another source of energy, provides 9 calories per gram. Fat is involved in the absorption of fat-soluble vitamins, cell signaling, and insulation of organs and is a structural and functional component of cell membranes. Fat adds taste, texture, and energy to food and can be very satiating.

Polyunsaturated fats, omega-3 fatty acids, and omega-6 fatty acids are considered essential. Other types of fats include saturated fat, trans fat, and monounsaturated fat.

There is a dispute over the best percentage of calories from fat. Recommendations should be individualized based on needs and overall health. The American Heart Association (AHA) recommends consuming no more than 6% of your calories from saturated fat for heart health.

Water

Your body is about two-thirds water. Every cell relies on it to function and repair, and without it in your diet you would only be able to survive a few days.

Water is important for preventing dehydration, lubricating joints, maintaining a normal body temperature, protecting your spinal cord and other tissues, and getting rid of waste through urination, sweat, perspiration, and bowel movements.

Fluid needs vary based on physical activity, the amount lost (for example, in sweat), whether you are sick with a fever, take certain medicines, and more. Estimates for water needs are about 15.5 cups for males and 11.5 cups for females. This includes water from all sources—drinking water, water in other beverages, and food.

Vitamins

Vitamins are organic compounds that are required in the diet in small amounts to maintain body functions (ex: growth, metabolism, cellular integrity). Vitamins are often classified into two categories, water-soluble vitamins and fat-soluble vitamins.

Water-soluble vitamins include:

• Vitamin B1 (thiamine)
• Vitamin B2 (riboflavin)
• Vitamin B3 (niacin)
• Vitamin B5 (pantothenic acid)
• Vitamin B6 (pyridoxine)
• Vitamin B7 (biotin)
• Vitamin B9 (folate)
• Vitamin B12 (cyanocobalamin)
• Vitamin C

Fat-soluble vitamins include:

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

You can meet your nutrient requirements through food, however, some people need to use supplements to bridge the gap.

Minerals

Minerals are inorganic molecules that play key roles in assisting bones, muscles, heart, and brain to work properly. Minerals are also important for making enzymes and hormones. Macrominerals are needed in larger amounts, while trace minerals are required in smaller amounts.

Macrominerals include:

• Calcium
• Chloride
• Magnesium
• Phosphorus
• Potassium
• Sodium
• Sulfur

Trace minerals include:

• Cobalt
• Copper
• Fluoride
• Iodine
• Iron
• Manganese
• Selenium
• Zinc

Eating a wide variety of foods is important for meeting your needs. However, in some instances, supplementation may be needed. People who take certain types of medicines or those who have medical conditions, such as kidney disease, may need to consume less of certain minerals.

Best Essential Nutrient Foods 

Most foods have an abundance of nutrients. For example, beans contain some carbohydrates, fat, and protein, prebiotic fiber, folate, potassium, iron, magnesium, zinc, calcium as well as plant-based polyphenols.

Some foods are more nutrient-dense than others. An ideal way to maximize your nutrition is to eat a variety of whole foods daily, including fruits, vegetables, nuts, seeds, legumes, whole grains, lean proteins, and healthy fats.

No single food contains 100% of your daily needs for every macro and micronutrient. Instead, your overall eating pattern will help you achieve your nutrient requirements. Aim to consume a variety of:

Colorful fruits and vegetables provide ample amounts of vitamins, minerals, fiber, carbohydrates, and antioxidants. Seasonal and frozen fruits and vegetables may contain higher amounts of available nutrients because they require less travel or are frozen at peak freshness. Choose fruits and vegetables with no added sugar, sodium, or fat.

Whole grains are intact grains containing the germ, bran, and endosperm of the grain. As compared to refined grains that have not been fortified, whole grains contain more fiber, vitamins, and minerals. They also contain plant-based protein, B vitamins, vitamin E, magnesium, iron, and fiber. Examples are farro, barley, bulgur, quinoa, amaranth, brown rice, and wild rice.

Low-fat and fat-free dairy milk, kefir, yogurt, and cottage cheese contain calcium, vitamin D, potassium, and protein with less saturated fat than full-fat types. Fermented dairy products like kefir and yogurt contain probiotics (beneficial live microbes). Dairy can contain iodine, an important trace mineral.

Lean protein can be provided by whole grains, fruits, legumes, tofu, soybeans, nuts, seeds, and vegetables. Lean animal protein includes chicken, turkey, fish, eggs, and low-fat cheese. Vitamin B12 is found exclusively in animal protein and nutritional yeast (for those who don’t eat animal foods).

Plants contain nonheme iron, while animal proteins contain heme iron. Many protein foods also contain choline, an important nutrient for your brain and nervous system; you need it to regulate memory, mood, muscle control, and more.

Nuts, seeds, and nut-butter provide energy, fiber, protein, heart-healthy fats, vitamins E and K, selected minerals such as magnesium, copper, potassium, selenium, carotenoids, and phytosterols with potential antioxidant action.

Other healthy fats include extra virgin olive oil, avocados, and olives. Monounsaturated fat has been linked to lower levels of cholesterol and reduced risk of coronary heart disease. Fatty fish and grass-fed meat will contain omega-3 fatty acids, as do walnuts, chia, flaxseed, and foods fortified with omega-3s.

Miscellaneous foods like seaweed and iodized salt contain iodine which is important for thyroid functioning and brain development during pregnancy and infancy. Seaweed is also considered a (nondairy) source of calcium and contains vitamin B12, and omega-3 fatty acids.

How Much of Each Essential Nutrient to Eat Daily 

The RDA for most vitamins and minerals is defined as intakes sufficient to meet the nutrient requirements of nearly all (97% to 98%) healthy individuals; often used to plan nutritionally adequate diets for individuals.

For the nutrients lacking data, there are “adequate intakes,” “estimated average intakes,” and “tolerable upper intake levels” (UL, the maximum daily intake unlikely to cause adverse health effects that are set as safety standards to prevent toxicity).

These amounts can be seen online in the Nutrient Recommendations and Databases site from the National Institutes of Health.

Guidelines provide general guidance, however, there are instances of increased needs of specific nutrients.

For example, an endurance athlete may have higher electrolyte requirements due to loss in sweat and increased carbohydrate and protein needs for performance and recovery. A person who is menstruating will require more iron. A person who is pregnant will have higher calorie requirements, and need more calcium, folate, and other nutrients.

Meal and Snack Inspiration With Every Essential Nutrient

Getting essential nutrients from food requires eating a wide variety of fruits, vegetables, nuts, seeds, starches like whole grains and starchy vegetables, legumes, lean protein, and healthy fats. Your overall dietary pattern is important for meeting your nutritional needs.

Supplementation is required when you cannot achieve a food-first approach to meet your nutrient requirements. For example, it is possible to hit your protein, vitamin, and minerals needs while following a plant-based diet (vegetarian diet), but careful consideration for certain nutrients like vitamin B12, calcium, iron, and zinc is important.

Some meal and snack inspirations include:

Breakfast: Oatmeal with strawberries, chopped walnuts, and fortified unsweetened nondairy milk (almond milk for example) with a slice of whole grain toast or sourdough topped with avocado and microgreens.

Lunch: Large salad filled with colorful fruits and vegetables, such as carrots, beans, scallions, tomatoes, onions, peppers, mushrooms, and grilled salmon with olive oil–based vinaigrette.

Snack: Whole fruit (apple, orange, berries) or unsweetened dates or prunes with a handful of nuts or tablespoon of nut butter, low-fat cheese, or dairy or nondairy yogurt.

Dinner: Possible meals include:

• Whole grain bowl: Quinoa (or another whole grain: brown rice, farro, millet, bulgur) with oven-roasted broccoli, chickpeas, and fermented onions tossed in a sweet chili dressing.
• Butternut squash soup topped with pumpkin seeds served alongside salad with tomatoes, peppers, edamame, cucumber, and sliced avocado.
• Grilled chicken, fish, or lean beef with baked potato and sautéed green beans (or other vegetable of choice). Side salad with vinaigrette.

Snack: Whole grain popcorn seasoned with nutritional yeast, garlic powder, and a pinch of iodized salt, or 1 cup of fruit salad.

Fluids: Aim to drink unsweetened beverages, such as water, coffee, tea, or seltzer. You can flavor them with mint, lemon, lime, or other herbs or fruits.

Remember that your portions will depend on your specific calorie needs to maintain, gain, or lose weight.

Risks of Nutritional Deficiencies

Nutritional deficiencies can occur when you follow restrictive diets for a long period of time, have food insecurity, issues with absorption, food allergies, or if your needs are increased during different phases of life and you are unable to hit your nutritional targets.

For example, having limited sun exposure and a condition that limits fat absorption can increase your risk of vitamin D deficiency. If you are not sure if you are at risk for certain nutrient deficiencies, contact a healthcare provider.

Summary

You need to consume adequate amounts of macronutrients (carbohydrates, protein, fat, water) and micronutrients (vitamins and minerals). Individualized nutrition is recommended as your needs are unique. Consuming a variety of vegetables, fruits, whole grains, legumes, lean proteins, nuts, seeds, and healthy fats can help meet your needs for essential nutrients.

Additionally, cultural considerations, maintaining the pleasure of eating, financial and medical situations, and your access to food can impact food choices and your ability to obtain your nutrient needs. When in doubt, contact a registered dietitian for education and support.