Do you like to keep up on nutrition, but are a bit puzzled sometimes about what you hear or read? Do you wonder what makes a carbohydrate simple or complex? Or what the difference is between a macronutrient and a micronutrient?
he body needs nutrients from foods and beverages for many vital functions including healthy growth and development, and smooth-running organs and body systems.
There are six types of nutrients: carbohydrates, protein, fat, vitamins, minerals and water. Carbohydrates, protein and fat are called macronutrients because our bodies need them in larger amounts. Vitamins and minerals are called micronutrients because our bodies need them in smaller amounts.
Macronutrients - The Big Three
Carbohydrates
Carbohydrates are the body’s main energy source, supplying 4 calories per gram. Carbohydrates are found in many foods and beverages including cereal, bread, rice, pasta, milk, vegetables, fruits, fruit juices, table sugar and honey. Carbohydrates are built from sugar units, and are classified as either simple carbohydrates or complex carbohydrates.
Simple carbohydrates are made up of one or two sugar units. They are found in sweet foods and drinks such as fruits, fruit juices, sweetened cereals, desserts, soft drinks, jam, syrup and table sugar. Complex carbohydrates are made up of many sugar units. They are found in starchy foods such as cereal, potatoes, pasta, beans and vegetables.
Dietary fiber is a type of complex carbohydrate that passes through the body without being digested. Fiber is found in whole grain cereals and breads, dried beans and peas, fruits and vegetables.
There are two types of dietary fiber—insoluble and soluble. Insoluble fiber promotes regularity by adding bulk to the stool, which helps it pass more quickly through the body. Insoluble fiber is found in foods such as bran cereals, whole-wheat bread, fruits and vegetables. Soluble fiber slows digestion, which helps minimize spikes in blood glucose, and helps lower blood cholesterol. Soluble fiber is found in foods such as oatmeal, barley, beans, peas and many fruits and vegetables.
Health experts recommend getting 45 to 65 percent of daily calories from carbohydrates.
Protein
The body needs protein for growth, repair and to make hormones, antibodies, enzymes and tissues. Protein is found in meat, poultry, fish, milk products, grains and beans, and supplies 4 calories per gram.
Health experts recommend getting 10 to 35 percent of daily calories from protein.
Fats
The body needs dietary fats for proper growth and development, a healthy nervous system and skin, to aid the absorption and transport of fat-soluble vitamins A, D, E and K through the blood, and to store energy in the body. Fats are made up of a mix of saturated and unsaturated fats. All fats supply 9 calories per gram.
Saturated fats are solid at room temperature and mainly found in animal foods such as fatty cuts of meat, whole milk, cheese, ice cream, butter, cream and lard. Tropical oils (palm oil, palm kernel oil, and coconut oil) also contain higher amounts of saturated fat. Eating too much saturated fat increases risk of heart disease by raising total cholesterol and LDL (“bad”) cholesterol.
Unsaturated fats are liquid at room temperature and mainly found in plant foods. There are three types of unsaturated fats: polyunsaturated, monounsaturated and trans fats.
Polyunsaturated fats are found in corn, soy and safflower oils, sunflower and sesame oil and seeds, walnuts, flaxseed, and fatty fish such as salmon. Monounsaturated fats are found in canola, olive and peanut oils, peanuts, almonds and avocados. Polyunsaturated and monounsaturated fats are considered healthful choices because they do not raise LDL cholesterol and help replace saturated fats in the diet.
Trans fats are formed when unsaturated liquid plant oils are partially hydrogenated, a process which makes them more solid and similar to saturated fats. Trans fats increase total cholesterol and LDL cholesterol, and lower HDL (“good”) cholesterol.
Health experts recommend getting 20 to 35 percent of daily calories from fats, mostly from unsaturated fats. Limit saturated fatty acids to less than 10 percent of calories and keep trans fatty acid consumption as low as possible.
Micronutrients - Small but Mighty
Vitamins and minerals are micronutrients that are crucial to many body processes. Many vitamins and minerals are essential, meaning we must get them from food or a dietary supplement such as a multivitamin.
Vitamins are classified as water-soluble or fat-soluble vitamins. The body doesn’t store water-soluble vitamins—excess amounts are excreted in the urine—so, you need an adequate supply of these vitamins each day. The body does store fat-soluble vitamins, so regularly consuming excessive amounts can be toxic.
Water-Soluble Vitamins
B vitamins
- B1 (thiamin)
- B2 (riboflavin)
- B3 (niacin)
- B6 (pyroxidine)
- B7 (biotin—also known as vitamin H)
- B9 (folate)
- B12 (cobalamin)
Pantothenic acidVitamin C
Fat-Soluble Vitamins
Vitamin A
Vitamin D
Vitamin E
Vitamin K
Minerals are classified as macrominerals or microminerals (also known as trace minerals) based on how much or little the body needs.
Macrominerals
- Calcium
- Magnesium
- Phosphorus
- Sodium
- Potassium
Microminerals
- Chromium
- Copper
- Fluoride
- Iodine
- Iron
- Manganese
- Molybdenum
- Nickel
- Selenium
- Tin
- Zinc
Water - Clearly Required
Water is often called the “forgotten” essential nutrient, but it is vital for our health. Water helps transport nutrients and oxygen to cells and carries waste products out of the body. It helps regulate body temperature, is part of most body fluids and cushions organs and joints.
The human body is about 50 to 75 percent water, depending on age, gender, body composition, food intake, physical activity level and environmental factors such as how hot it is outside.
Fluid sources of water include drinking water, milk, juice, coffee, tea and soft drinks. Many foods such as fruits and vegetables supply water, too.
Learn more about water intake guidelines from the Institute of Medicine’s recommendations for water intake for the general public, including children.
