An essential nutrient is a nutrient required for normal body function that either cannot be made by the body or cannot be made in amounts adequate for good health and therefore must be provided by the diet. Traditionally we think of the six essential nutrients as carbohydrate, protein, fat, vitamins, minerals and water.
Think of carbohydrates as the body’s source of fuel. All carbohydrates are broken down into glucose and used to fuel body systems and activity. We get carbohydrates from all plant foods – fruits, vegetables, grains, breads and cereals; from milk and dairy foods in the form of lactose and we get carbohydrate from sweets which contain sucrose or table sugar. Among the macro nutrients, carbohydrate, protein and fat there is a wide variety of choices that we can make for better health such as choosing fruits over sweets or skim dairy foods over full fat.
Protein is the body’s structural fabric. All our parts are made on a framework of protein. Our skeleton is a protein matrix hardened by the mineral calcium. Our organs and tissues are made of protein. All of the little pieces – blood cells, antibodies, neurons, hormones, and literally every cell in the body is made from protein. And all of these parts wear out with daily use. Dietary protein supplies the necessary pieces to build spare parts and replace them as we need them. We find protein in all meats, fish, eggs and dairy products. And we get smaller amounts of protein from beans, nuts, seeds, vegetables, grains and starches.
Fat is a concentrated source of food energy that provides more than twice the calories of carbohydrates. Our ancient ancestors needed fat to survive during times when there was little to eat. Eating high fat foods today can increase our risk for obesity and all of the chronic health problems associated with being overweight. The fats from meats, whole milk, cheese, ice cream and other animal sources are saturated fats and they clog our blood vessels increasing our risk of heart disease. Monounsaturated fats from olive oil, nuts, seeds and avocados and the omega-3-fats found in salmon and tuna reduce heart disease risk. Because all fats – healthy or not – are concentrated sources of calories, it is important to choose them wisely and manage serving size in order to maintain a healthy weight. If you weigh 200 lbs, it will take 60 minutes of walking to burn the 300 calories in a small order of french fries.
Vitamins are very small molecules that perform essential functions. The B vitamins niacin and thiamin are used in the process of producing energy from carbohydrate. Without them, we could not use the carbohydrate that we ate. Vitamin D helps us absorb calcium from the digestive system and it helps cells grow and develop. Vitamin C is used to make collagen, which provides structure to blood vessels, bone and ligaments.
Minerals are also very small and can be found on the periodic table in any chemistry classroom. Iron, a part built into red blood cells picks up and carries oxygen from our lungs to every cell in the body. Potassium maintains fluid volume inside and outside of cells and prevents the excess rise of blood pressure with increased sodium intake.
We get vitamins and minerals from all of the food groups. B vitamins and magnesium come from whole grains. Riboflavin (a B vitamin), potassium and calcium come from dairy foods. Iron and thiamin come from meats. Fruits, vegetables, beans, nuts and seeds are rich sources of many different vitamins and minerals. Generally all plant foods (not fried) are said to be nutrient dense which means they are low in calories and high in vitamins and minerals. This could also be said of skim and low fat dairy products as well as lean meats.
A balanced diet includes foods from all the food groups which is the best way to insure that we get all of the nutrients that are essential for good health. Choosing nutrient dense low calorie foods most of the time and maintaining an active lifestyle are two important fundamentals to a healthy and happy life.
Tim Scallon is a registered dietitian nutritionist with St. Luke’s Health. In cooperation with Sodexo Food Service, The Polk Education Center and the City of Lufkin, Tim Scallon hosts the nationally viewed TV series Memorial Cooking Innovations. The popular cooking show celebrates the joy of fresh food and healthy eating and can be seen on cable in 62 cities and online at http://www.chistlukeshealthmemorial.org. On the website find healthy recipes, past cooking shows and sound nutrition information.