Nutrition and Energy systems

1. Nutrition and Energy systems Topic 3(page 50 – 74 SEHS course companion)

2. 3.1 Nutrition To maintain good health you need 7 components of food (in balanced amounts). Good nourishment results in normal development, good health and good quality of life. Under nutrition, malnutrition and over nutrition can cause impaired growth / development, and diseases. Proper nutrition can give athletes the ‘edge’ they need to preform better. The 7 components are: • Carbohydrates • Protein • Lipid (Fat) • Water • Minerals • Vitamins • Fibre The components are divided into two categories Macro nutrients: Chemical compounds that form the bulk of our dietary consumption; primarily used for energy Micro nutrients: chemical compounds required in the diet in micro portions required for different functions within the body

4. Glucose Chemical composition of a glucose molecule is Carbon (C), Hydrogen (H) and Oxygen (O). Glucose (C6H12O6) is a saccharide made out of one molecule: a monosaccharide. This is the simplest form and most easy to used for body’s functions. When two monosaccharides combine they form a disaccharide. What is the ratio of carbon, hydrogen and oxygen molecules in glucose? 1:2:1

5. Condensation reaction(mono-, di-, poly-saccharides) When two monosaccharides are combined they form a disaccharide. This happens by taking out one molecule of water, this process is called the condensation reaction (dehydration synthesis). This is the linking of a monosaccharide to another monosaccharide, disaccharide or polysaccharide by the removal of a water molecule.

6. Approximate energy content per 100 grams • Carbohydrate: 1760 KJ • Protein: 1720 KJ • Lipid: 4000 KJ • Fat is an important source of food energy during the recovery phase between high intensity exercise and during prolonged exercise. • Lipids: • provide physical protection to vital organs and helps control body temperature. • play a major role in the synthesis of hormones, vitamin D (sterols) and cell membranes (sterols and phospholipids. • are important for fat soluble vitamins

7. Triacylglycerols, high concentrated energy stores Triacylglycerols are synthesized from three fatty acids joined together by one glycerol molecule. Glycerol by itself is a small carbohydrate molecule containing three carbons. Triacylglycerols are the form in which fat energy is stored in adipose tissue. The various dietary plant oils, such as olive oil and nut/seed oil are also triacylglycerols. Consider a typical 70kg man, who has fuel reserves of 100,000 kcal (420,00KJ) in triacylglycerols, 25,00 kcal (100,000 KJ) in protein (mostly in muscle), 600 kcal (2500 KJ) in glycogen, and 40 kcal (170 KJ) in glucose. Triacylglycerols constitute about 11kg of his total body weight. If this amount of energy were stored in glycogen, his total body weight would be 55kg greater. The glycogen and glucose stores provide enough energy to sustain biological function for about 24 hours, whereas the triacyglycerol stores allow survival for several weeks. In the body, the main site for accumulating triacyglycerol is in the cytoplasm of adipose cells (fat cells). Adipose cells are specialized for the synthesis and storage of triacylglycerols and for their mobilization into fuel molecules that are transported to other tissues by the blood Pic: http://courses.washington.edu/conj/membrane/fattyacids.htm

8. Saturated vs. unsaturated fatty acids The presence of unsaturated fatty acids in a triacylglycerol molecule makes it more fluid. This is due to the presence of the kinks in unsaturated fatty acids, which keeps the fatty acid chains from aligning uniformly. This is why plant fat oils, which contain primarily unsaturated fatty acids, are more liquid than animal fats. Unsaturated fatty acids are “partially hydrogenated” chemically for commerce to make the plant fatty acids more solid and improve self-life. Studies show a correlation between the consumption of trans fatty acids and increased risk of heart disease. • Saturated fatty acids: no double bonds, originate from animal sources (meat, poultry, dairy, palm oil and coconut oil) • Unsaturated fatty acids: have double bonds between individual carbon atoms within fatty acid chain, originates from plant based foods (olive oil, avocado, nuts, canola oil and seeds.

9. Protein Proteins are food fuels which provide the building molecules for tissue and enzymes (hormones) within all body organs. Proteins are found in most foods and in large quantities in meat, eggs and dairy products. It’s needed for growth and body (re)building. For example protein is used to increase the strength of muscle fibers. Damaged tissues (resulting from fractures, dislocations, sprains, muscle strains and bruising – often happening during physical activity) need protein to repair injured structures. Proteins are also essential to the immune system, in transport and communication, in the manufacture of enzymes for metabolic functioning but they are used as a energy source only when the body is depleted of almost all carbohydrates and fat sources Basic structure of amino acids. “R” indicates another atom or molecular structure attached to the carbon atom, this side chain distinguishes the the physical and chemical properties. Proteins are formed by amino acids, compounds made of Carbon (C), Oxygen (O), Hydrogen (H) and Nitrogen (N) atoms

10. Essential amino acids vs. non-essential amino acids These cows are eating essential amino acids NOT making essential amino acids Essential amino acids can’t be synthesized by the human body and must be obtained through nutrition, non-essential amino acids can be synthesized by the human body

11. Essential amino acids 20 amino acids have been identified as being required for the synthesis of protein, of the twenty 9 are essential Isoleucine Leucine Lysine Methionine Phenylalanine Threonine Tryptophan Valine Histidine • Protein are a source of energy: 100 grams of protein makes 1720KJ • Functions of proteins: • Structural muscles, bones, skin, hair, cells • Transport/communication plasma protein, hormones, receptors, neurotransmitters • Protective antibodies, mucus, anti-inflammatory proteins • Enzymatic digestion, metabolic pathways, O2 and CO2 transport

12. Recommendations for a health diet Recommendations are per day Carbs: 300gr. 55% Protein: 45- 65gr. Lipids: • Unsaturated 40 – 80 gr. • Saturated 20 – 30 gr. Fiber: 25 (women) - 38 gr. (men) Water: 1.6 - 1.9lt. fluids Salts: < 6 gr. per day

13. Endurance athlete vs. non-athlete Practical applications in sports nutrition. Endurance and ultra endurance athletes