by Kevin Myles (Author of The Diet That Works!)
Nutrition by definition is the consumption, digestion, and assimilation of foods and other nutrients for conversion into structural compounds (skin, muscle, hair, etc.) and functional processes (growth, energy, metabolic maintenance, etc.). The value of nutrition ranges from basic survival to optimal health and culminates for the athlete into maximum performance. Nutrients can be either; essential (those which cannot be produced by the body) or non-essential (those which can be manufactured from other nutrients). These nutrients are derived from food and are divided into macronutrients (water, protein carbohydrates, and fats) and micronutrients (vitamins, minerals, and trace elements). It is the regular consumption of food nutrients that make up a diet.
Macronutrients are the food elements required daily in quantities determined by weight, usually ounces or grams, which ultimately provide the energy necessary to maintain body functions during rest and physical activity. Macronutrients also provide the materials necessary for structural growth, maintenance, and repair. Calories, the measurable heat energy of food that can be either utilized or stored, are provided by the macronutrients. Protein and carbohydrates each contain approximately 4 kcal per gram with fat containing 9 kcal per gram and alcohol 7 kcal per gram. (Kcal=Kilocalories but is most commonly referred to as just calories).
Micronutrients are the vitamins, minerals, trace elements, and bio molecules required by the body in small amounts, usually measured in milligrams and micrograms. They act as co-factors in making other bio molecules and function as enzymes, electrolytes, catalyst, and have some structural roles. They do not provide a significant amount of calories to the body but in some cases can contribute greatly to disease prevention and the maintenance of optimal health.
The seven elements of food; protein, carbohydrates, fats, vitamins, minerals, water, and trace elements, all combine to make up the foundational components of nutrition. Each has it own definitive purpose and role:
Protein- Long chains of amino acid that have a number of structural functions. Protein comprises 80% of the dry weight of muscle and 90% of the dry weight of blood. It is the food most responsible for the growth and repair of tissue and can be derived from both plant and animal sources. Ingested protein is broken down by the body into its building blocks, the amino acids, before it can then be assimilated and utilized for innumerable functions. The proper balance between protein intake versus protein breakdown is of vital importance.
Carbohydrates- High energy foodstuffs that are composed of carbon, hydrogen, and oxygen in chemical substances that include sugars, starches, glycogen, dextrose, and cellulose. Carbohydrates contain the body’s main source of the raw materials for energy and are classified as either simple or complex. The body stores carbohydrates in the muscles and liver as glycogen. Since excess carbohydrate intake beyond energy and recovery needs can lead to fat storage, carbohydrate manipulation is one of the keys to controlling body composition.
Fats- As the most concentrated source of energy in the diet, fats contain more than twice the energy of carbs or protein. Fats are made up of saturated fatty acids which come primarily from animal sources and are solid at room temperature and unsaturated fatty acids which come primarily from vegetables, seeds, and nuts, and are usually liquid. Fats, also known as lipids, by definition are soluble in organic solvents but not in water. Fats are essential to health and also have many important structural functions. Generally speaking, humans consume too much of the wrong types of fats and not enough of the good fats. The different types of lipids include; triglycerides, fatty acids, essential fatty acids, Omega 3 fatty acids, Gamma Linolenic Acid, Medium Chain Triglycerides, Phospholipids, lecithin, and cholesterol. Triglycerides make up about 98% of all the fats in the diet.
Vitamins- These are organic food substances, found in both plants and animals, that are essential in small amounts for numerous metabolic functions, energy production and normal good health. Vitamins are generally classified as either fat soluble or water soluble and can be derived from foods and addition supplementation. The deficiencies of certain vitamins can lead to severe medical conditions and an adequate amount is considered beneficial for optimal athletic performance.
Minerals- These are inorganic compounds that are essential nutrients required by the body in very small amounts. They are important in many structural and metabolic roles and make up 4-6% of the body. They are categorized as macro minerals, trace elements, and electrolytes and can be as important as vitamins to overall health and athletic performance. Dietary surveys have determined that most athletes’ diet are deficient in one or more minerals.
Water- As the most vital of all nutrients, water can make up as much as 70% of a persons body mass. Water aids in the digestion, transportation and assimilation of all other nutrients. It also aids in heat stabilization as it absorbs considerable heat with only small changes in temperature. It is vitally important for all athletes to maintain proper water balance and remain properly hydrated at all times. The body derives water from consuming liquids, ingesting foods, particularly fruits and vegetables, and metabolic water produced when food molecules become metabolized for energy.
Having a basic knowledge and understanding of nutrition will lay the perfect foundation for developing the individual nutritional practices necessary to achieving your fitness goals.