Macronutrients
Macronutrients are energy yielding nutrients that are needed in large amounts to sustain the body. This video gives a quick explanation of what the macronutrients do in the body.
In general, the more intense activity one participates in, the more carbohydrates are used and less fats are used. Less intense activity may need a higher amount of fat and less carbohydrates. This is because the body uses carbohydrates more as intensity increases.
The page below provides a little more information to gain a better understanding of each nutrient.
Carbohydrates
Carbohydrates are the preferred source of energy for the body. Carbohydrates (CHO) are generally broken down into two categories- simple (quickly digested) and complex (fibrous, slower digesting). One gram of CHO yields approximately four calories. CHO should consist of 45-65% of your calories- for active people, 2-4g/lb of bodyweight but ultra-endurance athletes may need 5g/lb. per day.
1g of Carbohydrates = 4 calories
Simple carbohydrates include monosaccharides and disaccharides. Mono (meaning one) and saccharide (sugar) means the molecule is one sugar. Monosaccharides include:
Glucose (dextrose, blood sugar)
Fructose (fruit)
Galactose (dairy, avocados, gums)
Almost all fructose is metabolized, depending on intake. Excess intake may be converted to glycogen (to be used by muscles), lactic acid, or fat (intakes of 2x more than typical intake). The amount of CHO in the diet influences the amount of glycogen stored.
Disaccharides are made when two monosaccharides create a bond together.
Maltose= 2x glucose (starch-rich foods)
Lactose= galactose + glucose (dairy)
Sucrose= fructose + glucose (table sugar)
The main function of glucose is to yield energy. Other sugars can generally be converted to glucose. Red blood cells and most of the brain get almost all energy from glucose. Glucose is used in a much greater capacity during intense activity.
Glucose is protein-sparing. If CHO intake is sufficient, amino acids can be used to make body tissues (may be used to build muscle or stored as fat in great excess). If glucose levels are insufficient in the body, gluconeogenesis occurs (your body makes glucose from other products like amino acids and fatty acids). This is one reason why CHO intake while trying to add muscle mass is critical.
Lipids (Fats)
Lipids include:
Triglycerides
Fatty acids
Phospholipids
Sterols (cholesterol being the most recognizable).
Lipids should not exceed 20-35% of your daily calories; with an emphasis on mono-unsaturated fats (avocado, olive, and nut oils). Lipids are more energy-dense, with 1 gram of lipids yielding 9 calories.
1g of Fats = 9 calories
Most people have heard of unsaturated, saturated, and trans fats. The difference in these lipids is in the chemical structures. Unsaturated fats have a lower melting point than saturated fat, and trans fats have an even higher melting point than saturated fat. The melting point essentially shows that it is harder to breakdown the chemical structure. So, Unsaturated Fat > Saturated Fat > Trans Fat. In terms of energy balance, it takes more work to breakdown trans fat.
Essential Fatty Acids
Despite the bad reputation, some fats are essential to one's diet (cannot be made by the body). Omega-3 and Omega-6 fatty acids may help lower risk heart disease, depression, and dementia. These fatty acids are found in baked/broiled fish, walnuts, flax seeds, olive oil, and avocado oil.
Triglycerides
Triglycerides (TGs) are non-essential but are used as the main fuel for muscles at rest and during light activity. Glucose is used more during high intensity activity.
Triglycerides can increase fat cells about 50x in weight! If this is outdone, more fat cells are created. Fat cells shrink but they are extremely difficult to make them go away. This is why it is generally harder to lose weight than it is to gain weight. Fat-Soluble Vitamins (A, D, E, K) are transported via TGs.
Hydrogenated oils lead to trans fat (shortening and margarine). These are not fully saturated but partially hydrogenated fats. Foods high is trans fat are doughnuts, cake, fries, chips, and cookies. These foods are not typically considered the healthiest option.
Protein
Protein is a large molecule consisting of chains of amino acid residues. Protein helps with repairing and building tissue, keep the immune system functioning, and plays an important role in the maintenance of hormones and enzymes. Chicken breast, turkey breast, lean ground beef, seafood, and eggs are high quality sources of protein (lower fat, higher protein).
Most active adults need about 0.5-0.7g protein per pound of bodyweight. Growing teens need a little more: between 0.7-0.9g per pound of bodyweight.
Your total daily calorie intake should consist of 15-30% from protein.
1g Protein = 4 calories
Protein is made of chains of amino acid residues. Of the 21 amino acids, nine of them are essential (cannot be produced in the body). Beyond soy protein, plant proteins do not have ample amounts of essential amino acids so foods must be consumed in balance to achieve the proper balance of essential amino acids.
While it is possible to meets protein requirements following a vegetarian or vegan diet, animal protein has a higher bio-availability of protein. This means that more of the protein consumed can be used in the body.
Weight Gain and Weight Loss
Weight Gain
Gaining weight may be a challenge for some for many different reasons. If someone is looking to gain weight to improve performance, it is best to aim for a change of 1-2% per month for guys and 0.5-1.5% per month for ladies. For a 150 lbs athlete, that means about 1.5lbs per month. A quick change in weight will likely lead to more fat gain than muscle gain. Eating 15-20 calories per pound of target body weight should be a good starting point when looking to add weight.
Eating 15-20 calories per pound of target body weight is a good starting point when looking to add weight.
Weight Loss
If someone is looking to lose weight to improve performance and/or health, it is best to be more conservative with a loss of 0.5-1% per week. For a 150 lbs athlete, that means no more than 1.5lbs per week. Losing weight at a quicker rate will metabolize more muscle than if one were to lose weight more slowly.