energy (nutrition class)

Energy is measured in calories. The term calorie is familiar to most people. Many of us think of calories as something to avoid, but we need calories to keep us alive and moving. Calories are the units we use to quantify the amount of energy a food provides when eaten. So, technically we don’t eat calories; we eat food that provides energy measured in calories. Food and the energy it provides are essential to maintain life. Energy is used to do body work, whether it is breathing, walking to the mailbox, or running a marathon. When our diets provide the same number of calories as we use each day to stay alive and active, our body weight remains the same. If we consume more calories tha we need, the extra energy is stored in our bodies, mostly as fat, and we gain weight. If we consume fewer calories than we need, our bodies use their stored energy and we lose weight.

Nutrients provide structure. Most of our body weight is due to water, protein and fat. These nutrients, along with the minerals, are needed to form and maintain the shape and structure of the body. For instance, the muscles that help define our body contours are made up of water and protein. Proteins form the ligaments and tendons that hold our bones together and attach our muscles to our bones. Protein is also important in the structure of our bones and teeth because it forms the framework that is hardened by mineral deposits. Fat also has an effect on the size and shape of our bodies. Someone with more fat is rounder and softer with someone with less fat and more muscle. On a smaller scale, lipids, proteins, and water form the structure of cells. Lipid and protein make up the membranes that surround each cell, and water fills the cells and and the spaces around them.

Nutrients help regulate body processes. In order to keep your body functioning, thousands of chemical reactions and physiological processes are going on all the time. Despite all this activity, your body temperature, blood pressure, blood sugar level, and hundreds of other parameters remain relatively constant. This state in which conditions inside the body are maintained in a healthy range is called homeostasis. Nutrients help regulate body processes to maintain homeostasis. All six classes of nutrients have important regulatory molecules called hormones that run on or turn off various body processes, and proteins, vitamins and minerals are needed to mhelp regulate how uickly chemical reactions take place throughout the body.