Nutrition basics

The basics of good nutrition are the same for women and men: Choose healthy foods most of the time and limit the amount of unhealthy foods you eat. Healthy eating means choosing the right amount of foods from all the food groups and getting the nutrients your body needs.

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What is a nutrient?

A nutrient is any substance in food that:

  • Provides energy
  • Helps your body "burn" another nutrient to provide energy
  • Helps build or repair tissue

The different types of nutrients include:

  • Proteins
  • Carbohydrates
  • Fats
  • Vitamins
  • Minerals
  • Water

Proteins

Proteins are an important part of your bones, muscles, and skin. In fact, proteins are in every living cell in your body. Inside cells, proteins perform many functions, including:

  • Helping to break down food for energy
  • Building structures
  • Breaking down toxins

Proteins are made up of building blocks called amino acids. Your body can make some amino acids but not others. Proteins that you get from meat and other animal products contain all the amino acids you need. These include both those your body can make and those it can't. Proteins from meat and other animal products are known as complete protein.

Proteins from plant products are incomplete proteins. That means that the proteins from one plant product don't contain all the amino acids your body needs. But another plant product may have the amino acids that the first one is missing. To get complete protein from plants, you need to eat a variety of plant foods. For instance, eating rice with beans or peanut butter with bread will give you complete protein.

You may have seen ads for protein powders and shakes that say their products contain amino acids that your body can't make. Although this is true, most people can get all the protein they need from food and don't need protein supplements.

Good sources of protein

Good sources of protein include:

  • Fish and shellfish
  • Poultry
  • Red meat (beef, pork, lamb)
  • Eggs
  • Nuts
  • Peanut butter
  • Nut butters
  • Seeds
  • Beans
  • Peas
  • Lentils
  • Soy products (tofu, tempeh, vegetarian burgers)
  • Milk
  • Milk products (cheese, cottage cheese, yogurt)

Carbohydrates

The foods you eat contain different types of carbohydrates (kar-boh-HEYE-drayts). Some kinds are better for you than others. The different types of carbohydrates are:

  • Sugars are found naturally in fruits, vegetables, milk, and milk products. Foods such as cakes and cookies have had sugars added. Table sugar also is an added sugar. All of these sugars can be converted in your body to glucose, or blood sugar. Your cells "burn" glucose for energy.
  • Starches are broken down in your body into sugars. Starches are found in certain vegetables, such as potatoes, beans, peas, and corn. They are also found in breads, cereals, and grains.
  • Dietary fibers are carbohydrates that your body cannot digest. They pass through your body without being broken down into sugars. Even though your body does not get energy from fiber, you still need fiber to stay healthy. Fiber helps get rid of excess fats in the intestine, which helps prevent heart disease. Fiber also helps push food through the intestines, which helps prevent constipation. Foods high in fiber include fruits, vegetables, beans, peas, nuts, seeds, and whole-grain foods (such as whole-wheat bread, oatmeal, and brown rice).

Healthy and unhealthy carbohydrates

In general, you want to limit carbohydrates that increase your blood glucose levels. If your blood glucose stays high for too long, you can develop type 2 diabetes. To keep your blood glucose in check, limit the amount of table sugar you eat. Also, limit foods with added sugars. You can tell if a food has added sugars by looking at the ingredients list on the package. Look for terms such as:

  • Corn sweetener
  • Corn syrup
  • High-fructose corn syrup
  • Dextrose
  • Fructose
  • Glucose
  • Lactose
  • Maltose
  • Sucrose
  • Honey
  • Sugar
  • Brown sugar
  • Invert sugar
  • Molasses
  • Malt syrup
  • Syrup

You also should limit the amount of white potatoes you eat. Eating white potatoes occasionally is fine because they contain important vitamins and minerals. But your body rapidly digests the starch in white potatoes. This can raise your blood glucose level.

Healthy carbohydrates include:

  • Natural sugars in fruits, vegetables, milk, and milk products
  • Dietary fiber
  • Starches in whole-grain foods, beans, peas, and corn

Fats

Your body needs some fat to function properly. Fat:

  • Is a source of energy
  • Is used by your body to make substances it needs
  • Helps your body absorb certain vitamins from food

But not all fats are the same. Some are better for your health than others. To help prevent heart disease and stroke, most of the fats you eat should be monounsaturated (mon-oh-uhn-SACH-uh-ray-tid) and polyunsaturated (pol-ee-uhn-SACH-uh-ray-tid) fats.

Foods high in monounsaturated fats include:

  • Olive oil
  • Peanut oil
  • Canola oil
  • Avocados
  • Most nuts

Foods high in polyunsaturated fats include:

  • Safflower oil
  • Corn oil
  • Sunflower oil
  • Soybean oil
  • Cottonseed oil

Healthy and unhealthy fats

Omega-3 (oh-MAY-guh) fatty acids are a type of polyunsaturated fat that appear to reduce your risk of heart disease. Good sources of omega-3s are fatty fish. These include salmon, trout, herring, mackerel, anchovies, and sardines. You can also get omega-3s from plant sources. These include ground flaxseed (linseed), flaxseed oil, and walnuts. Small amounts are also found in soybean and canola oils.

Less healthy kinds of fats are saturated and trans fats. They can increase your risk of heart disease by causing the buildup of a fatty substance in the arteries carrying oxygen-rich blood to your heart. When this happens, your heart does not get all the blood it needs to work properly. The result can be chest pain or a heart attack. These fats can also increase your risk of stroke by causing the buildup of the same fatty substance in arteries carrying blood to your brain. Research also suggests that eating lots of trans fats may increase your risk of breast cancer.

Foods high in saturated fats include:

  • Red meat (beef, pork, lamb)
  • Poultry
  • Butter
  • Whole milk and whole milk products
  • Coconut oil
  • Palm oil

Trans fats are found in foods made with hydrogenated (heye-DROJ-uh-nay-ted) and partially hydrogenated oils. Look on the ingredients list on the food package to see if the food contains these oils. You are likely to find them in commercial baked goods, such as crackers, cookies, and cakes. Trans fats are also found in fried foods, such as doughnuts and french fries. Stick or hard margarine and shortening are also high in trans fats.

As with saturated and trans fats, eating too much cholesterol (koh-LESS-tur-ol) can raise your risk of heart disease and stroke. Cholesterol is a fat-like substance found in animal products, such as:

  • Red meat
  • Poultry
  • Seafood
  • Egg yolks
  • Milk and milk products
  • Lard
  • Butter

Although monounsaturated and polyunsaturated fats are better for your health than saturated and trans fats, eating large amounts of any fat can cause weight gain. You should eat fats in moderation. And make sure that fatty foods don't replace more nutritious foods, such as fruits, vegetables, and whole grains.

Vitamins

Vitamins are substances found in foods that your body needs for growth and health. There are 13 vitamins your body needs. Each vitamin has specific jobs. Below is a list of the vitamins, some of their actions, and good food sources.

Vitamins, some of their actions, and good food sources
Vitamin Actions Sources
A
  • Needed for vision
  • Helps your body fight infections
  • Helps keep your skin healthy
Kale, broccoli, spinach, carrots, squash, sweet potatoes, liver, eggs, whole milk, cream, and cheese.
B1
  • Helps your body use carbohydrates for energy
  • Good for your nervous system
Yeasts, ham and other types of pork, liver, peanuts, whole-grain and fortified cereals and breads, and milk.
B2
  • Helps your body use proteins, carbohydrates, and fats
  • Helps keep your skin healthy
Liver, eggs, cheese, milk, leafy green vegetables, peas, navy beans, lima beans, and whole-grain breads.
B3
  • Helps your body use proteins, carbohydrates, and fats
  • Good for your nervous system and skin
Liver, yeast, bran, peanuts, lean red meats, fish, and poultry.
B5
  • Helps your body use carbohydrates and fats
  • Helps your body make red blood cells
Beef, chicken, lobster, milk, eggs, peanuts, peas, beans, lentils, broccoli, yeast, and whole grains.
B6
  • Helps your body use proteins and fats
  • Good for your nervous system
  • Helps your blood carry oxygen
Liver, whole grains, egg yolk, peanuts, bananas, carrots, and yeast.
B9 (folic acid or folate)
  • Helps your body make and maintain new cells
  • Prevents some birth defects
Green leafy vegetables, liver, yeast, beans, peas, oranges, and fortified cereals and grain products.
B12
  • Helps your body make red blood cells
  • Good for your nervous system
Milk, eggs, liver, poultry, clams, sardines, flounder, herring, eggs, blue cheese, cereals, nutritional yeast, and foods fortified with vitamin B12, including cereals, soy-based beverages, and veggie burgers.
C
  • Needed for healthy bones, blood vessels, and skin
Broccoli, green and red peppers, spinach, brussels sprouts, oranges, grapefruits, tomatoes, potatoes, papayas, strawberries, and cabbage.
D
  • Needed for healthy bones
Fish liver oil, milk and cereals fortified with vitamin D. Your body may make enough vitamin D if you are exposed to sunlight for about 5 to 30 minutes at least twice a week.
E
  • Helps prevent cell damage
  • Helps blood flow
  • Helps repair body tissues
Wheat germ oil, fortified cereals, egg yolk, beef liver, fish, milk, vegetable oils, nuts, fruits, peas, beans, broccoli, and spinach.
H (biotin)
  • Helps your body use carbohydrates and fats
  • Needed for growth of many cells
Liver, egg yolk, soy flour, cereals, yeast, peas, beans, nuts, tomatoes, nuts, green leafy vegetables, and milk.
K
  • Helps in blood clotting
  • Helps form bones
Alfalfa, spinach, cabbage, cheese, spinach, broccoli, brussels sprouts, kale, cabbage, tomatoes, and plant oils. Your body usually makes all the vitamin K you need.

Minerals

Like vitamins, minerals are substances found in food that your body needs for growth and health. There are two kinds of minerals: macrominerals and trace minerals. Macrominerals are minerals your body needs in larger amounts. They include calcium, phosphorus, magnesium, sodium, potassium, and chloride. Your body needs just small amounts of trace minerals. These include iron, copper, iodine, zinc, fluoride, and selenium.

Minerals, some of their actions, and good food sources
Mineral Actions Sources
Calcium
  • Needed for forming bones and teeth
  • Helps nerves and muscles function
Canned salmon with bones, sardines, milk, cheese, yogurt, Chinese cabbage, bok choy, kale, collard greens, turnip greens, mustard greens, broccoli, and calcium-fortified orange juice.
Chloride
  • Needed for keeping the right amounts of water in the different parts of your body
Salt, seaweed, rye, tomatoes, lettuce, celery, olives, sardines, beef, pork, and cheese.
Copper
  • Helps protect cells from damage
  • Needed for forming bone and red blood cells
Organ meats, shellfish (especially oysters), chocolate, mushrooms, nuts, beans, and whole-grain cereals.
Fluoride
  • Needed for forming bones and teeth
Saltwater fish, tea, coffee, and fluoridated water.
Iodine
  • Needed for thyroid gland function
Seafood, iodized salt, and drinking water (in regions with iodine-rich soil, which are usually regions near an ocean).
Iron
  • Helps red blood cells deliver oxygen to body tissues
  • Helps muscles function
Red meats, poultry, fish, liver, soybean flour, eggs, beans, lentils, peas, molasses, spinach, turnip greens, clams, dried fruit (apricots, prunes, and raisins), whole grains, and fortified breakfast cereals.
Magnesium
  • Needed for forming bones and teeth
  • Needed for normal nerve and muscle function
Green leafy vegetables, nuts, bran cereal, seafood, milk, cheese, and yogurt.
Phosphorus
  • Needed for forming bones and teeth
  • Needed for storing energy from food
Milk, yogurt, cheese, red meat, poultry, fish, eggs, nuts, peas, and some cereals and breads.
Potassium
  • Needed for normal nerve and muscle function
  • Needed for keeping the right amounts of water in the different parts of your body
Milk, bananas, tomatoes, oranges, melons, potatoes, sweet potatoes, prunes, raisins, spinach, turnip greens, collard greens, kale, most peas and beans, and salt substitutes (potassium chloride).
Selenium
  • Helps protect cells from damage
  • Needed for thyroid gland function
Vegetables, fish, shellfish, red meat, grains, eggs, chicken, liver, garlic, brewer's yeast, wheat germ, and enriched breads.
Sodium
  • Needed for normal nerve and muscle function
  • Needed for keeping the right amounts of water in the different parts of your body
Salt, milk, cheese, beets, celery, beef, pork, sardines, and green olives. (Many people get too much sodium. For tips on cutting back, see Reducing your sodium.)
 
Zinc
  • Needed for healthy skin
  • Needed for wound healing
  • Helps your body fight off illnesses and infections
Liver, eggs, seafood, red meats, oysters, certain seafood, milk products, eggs, beans, peas, lentils, peanuts, nuts, whole grains, fortified cereals, wheat germ, and pumpkin seeds.

Water

Water is an important part of your body. In fact, it makes up more than 60 percent of your body weight. Among other functions, water:

  • Moistens tissues, such as those around your mouth, eyes, and nose
  • Regulates your body temperature
  • Cushions your joints
  • Helps your body get nutrients
  • Flushes out waste products

How much water should I drink?

Without water, you would die in a few days. So it's important that you get enough water. But how much water is enough? Experts generally recommend that you drink six to eight 8-ounce glasses of fluid every day. But it doesn't have to be all water. You could satisfy some of your fluid needs by drinking milk, tea, soda, coffee, or juice, which are composed mostly of water. Just remember that juice and sodas are high in sugar. Many fruits and vegetables, such as watermelon and tomatoes, are also mostly water.

If you're being physically active and sweating a lot, you'll need more fluid. You'll also need more if the weather is hot. Women who are pregnant should drink about 10 cups of fluids daily. And women who breastfeed should drink about 13 cups of fluids daily.

It's generally not a good idea to use thirst alone as a guide for when to drink. By the time you're thirsty, you may already be a bit dehydrated. On the other hand, you don't need to be constantly carrying around water bottles and drinking lots of water. You are probably getting all the fluid you need if you are rarely thirsty and you produce a little more than six cups of colorless or slightly yellow urine a day. Dark urine can be a signal that you need more fluid.