The phrase “you are what you eat” dates back to the 1800s, but it’s taken decades of research since then to determine exactly what to eat to be as healthy as possible.
“Food is our body's fuel,” says Rebecca Solomon, RD, CDN, director of clinical nutrition at Mount Sinai Beth Israel in New York City. “If we don’t use high-grade fuel, we can’t expect high functioning.”
Healthy eating not only helps you live longer by preventing chronic diseases such as heart disease, diabetes, and cancer, but it also boosts energy and mood, increasing overall quality of life, says Natalie Stephens, RDN, LD, a registered dietitian at Ohio State University Medical Center in Columbus and president of the Ohio Academy of Nutrition and Dietetics. And, a smart diet helps you maintain a healthy weight and get a good night’s sleep.
The first step to reaping the benefits of healthy eating: understanding which nutrients your body needs and how to get them every day.
The 5 to Stay Alive
The human body needs a long list of nutrients every day. The essentials, though, are called “macronutrients,” and your body needs them to stay healthy and perform optimally. They include the following five:
1. Carbohydrates
Main function: Provide energy
“Carbohydrates are the body’s main energy source and the brain’s only source of fuel,” says Kate Patton, MEd, RD, a registered dietitian at the Cleveland Clinic in Ohio. Your body breaks carbohydrates down into glucose, which cells require to create energy.
Get more: The best sources of carbohydrates are whole grains and foods made from those grains, such as whole-wheat bread, bulgur, barley, oatmeal, brown rice, and cornmeal. Limit your intake of sugar and refined grains (including white pasta, white rice, and white breads), the U.S. Department of Agriculture (USDA) recommends.
2. Protein
Main function: Build and repair tissue
“Protein is another important source of energy for the body,” Solomon says. Protein consists of amino acids that act as the body’s main building blocks for tissues, such as muscle, skin, bone, and hair. Proteins also assist in many reactions in the body, including the production of enzymes (the catalysts that keep all body processes running smoothly), hormones, and antibodies, Solomon explains.
Get more: The best protein sources are lean meats, poultry and seafood, beans and peas, nuts and seeds, eggs, and soy products, according to the USDA.
3. Fats
Main function: Provide backup energy
“Your body uses fats for energy when carbohydrates aren’t available,” Patton says. “You also need fats as insulation, to help your body absorb fat-soluble vitamins, and to protect your organs.”
Get more: Fats come in both liquid and solid forms. The USDA notes that the best sources of healthful fats are the liquid monounsaturated and polyunsaturated fats found in olive oil, canola oil, sunflower oil, soybean oil, corn oil, nuts, seeds, and avocados, as well as fatty fish rich in omega-3 fatty acids. Limit foods high in unhealthy saturated fats (red meat, cheese, butter, and ice cream) and trans fats (processed products that contain partially hydrogenated oil), which increase your risk for disease.
4. Vitamins and Minerals
Main function: Maintain optimal health
“You need vitamins and minerals for numerous physiological functions that help you survive,” Patton says. They're essential for normal growth and development, and each one plays a unique role in helping to maintain optimal health. For example, calcium and vitamin D are necessary for healthy bones, and the B vitamins help support the nervous system, explains Tricia L. Psota, PhD, RDN, president-elect of the DC Metro Area Dietetic Association.
Get more: Vitamins and minerals come from a variety of foods, including fruits and vegetables, dairy products, and lean protein sources. “Eat a selection of colorful fruits and vegetables every day, and vary the types of proteins you eat,” Solomon says.
5. Water
Main function: Enables vital bodily functions
You’ve probably heard that you can live for weeks without food but only days without water. That’s because water is the most important essential nutrient. It is involved in many of your body’s vital functions, and it distributes other essential nutrients to your cells.
Get more: The Institute of Medicine recommends that men consume about 125 ounces of water a day and women 91 ounces per day. About 20 percent can come from foods, and the remaining 80 percent should come from drinking water — about 12 cups a day for men and 8.8 cups for women.
The Easy Way to Get Your Daily Nutrients
The amount of each nutrient you need depends on your age, height and weight, and activity level. “You can see a dietitian to get your own personalized plan, or go online and use the USDA’s My Weight Manager tool to determine your needs,” Stephens suggests.
In addition, an easy, memorable way to balance what you eat is to fill your plate at each meal using the USDA's Choose My Plate method. This strategy involves dividing the space on your plate at each meal this way:
- 1/2 for fruits and vegetables
- 1/4 for grains, preferably whole grains
- 1/4 for lean protein
Then round out each meal with 1 cup of milk (or 1 serving of other type of dairy) on the side.
“This method is balanced in carbohydrates and adequate in protein — Americans tend to overeat protein — and provides the vitamins and minerals we need every day,” Stephens says. “Add a glass of water to each meal to stay hydrated and prevent overeating, and you’re all set.”