[MEDT 03] CPH Lecture

• Nutrition


  The organic process of nourishing or being nourished; the processes by which an organism assimilates (digests) food and uses it for growth and maintenance
• Nutrition (in a broader sense)


  A process or series of processes by which the living organism as a whole (or its component parts or organs) is maintained in its normal condition of life and growth
• Nutrition (in a more limited sense)


  The process by which the living tissues take up, from the blood, matters necessary either for their repair or for the performance of their healthy functions
• Nutrition


  The science that deals with all the various factors of which food is composed and the way in which proper nourishment is brought about
• Average nutritional requirements


  • They are fixed and depend on measurable characteristics such as age, sex, height, weight, degree of activity, and rate of growth
• Good nutrition is the foundation of good health
• Nutrients


  • Macronutrients
  • Micronutrients
• Macronutrients


  • Water
  • Carbohydrates
  • Proteins
  • Fats
• Micronutrients


  • Vitamins
  • Minerals
• Water


  An essential nutrient that is involved in every function of the body
• Water


  • The human body is two-thirds water
  • Bone is 1/3 water
  • Muscle is 2/3 water
  • Fat is 1/4 water
  • Whole blood is 4/5 water
• Purposes and functions of water

  • Helps transport nutrients and waste products in and out of cells
  • Necessary for all digestive, absorption, circulatory, and excretory functions
  • Needed for the utilization of the water-soluble vitamins
  • Needed for the maintenance of proper body temperature
• Recommended water intake


  • Minimal amount, 4 glasses
  • Desirable range, 6-8 glasses/day
  • Optimal range, 8-10 glasses/day
• Carbohydrates


  Supply the body with the energy it needs to function
• Carbohydrates


  • They are the main source of blood glucose, which is a major fuel for all of the body's cells and the only source of energy for the brain and red blood cells
  • They provide the body with a source of fuel and energy that is required to carry out daily activities and exercise
  • They spare protein so that protein can concentrate on building, repairing, and maintaining body tissues instead of being used up as an energy source
  • They are necessary for the regulation of nerve tissue and are the ONLY source of energy for the brain
  • Certain types encourage the growth of healthy bacteria in the intestines for digestion
  • Some are high in fiber, which helps prevent constipation and lowers the risk for certain diseases such as cancer, heart disease and diabetes
  • 1 g carbs = 4 cal
• Monosaccharides


  • Glucose
  • Fructose
  • Galactose
• Disaccharides


  • Sucrose (glucose + fructose)
  • Lactose (glucose + galactose)
  • Maltose (glucose + glucose)
• Polysaccharides


  • Starch
  • Glycogen
  • Cellulose
• Fiber


  The part of plants that the body cannot digest, it provides bulk to the stool
• Types of fiber


  • Soluble fiber
  • Insoluble fiber
• Soluble fiber


  Found in beans, peas, lentils, oats, and barley, as well as some fruits and vegetables. Eating foods with soluble fiber may help to lower blood cholesterol and decrease the risk of heart disease, and may also help lower blood sugar levels
• Insoluble fiber


  Found in foods like wheat bran, whole grains and all vegetables and fruits. It is often called roughage or bulk because it keeps the digestive system running smoothly, helping with constipation, hemorrhoids, and other digestive problems, and may help to prevent some types of cancer
• Proteins


  They are found throughout the body and are essential for synthesis of body tissue in growth, maintenance, and repair
• Proteins


  • They make up the enzymes that power many chemical reactions and the hemoglobin that carries oxygen in our blood
  • Collagen, hormones, immune cells, DNA, and RNA are components of protein
  • They are involved in maintenance of osmotic pressure, clotting of blood, and muscle contraction
  • During starvation, they serve as the major suppliers of energy
• Amino acids


  The building blocks of proteins. Our bodies make amino acids in two different ways; either from scratch, or by modifying other amino acids. A few amino acids (known as essential amino acids) must come from food
• Animal sources of protein

  They tend to deliver all the amino acids we need
• Other protein sources


  Such as fruits, vegetables, grains, nuts, and seeds, lack one or more essential amino acids
• Vegetarians need to be aware that they need a variety of protein-containing foods each day in order to get all the amino acids needed to make new protein
• Fats


  They are the body's main form of long-term energy storage
• Functions of fats


  • Provides back-up energy if blood sugar supplies run out
  • Needed so the body can absorb the fat soluble vitamins A, D, E, K, and prevent deficiencies of these vitamins
  • Provides insulation under the skin from the cold and the heat
  • Protects organs and bones from shock and provides support for organs
  • Surrounds and insulates nerve fibers to help transmit nerve impulses
  • Part of every cell membrane in the body, helping to transport nutrients and metabolites across cell membranes
  • Used by the body to make a variety of other building blocks needed for everything from hormones to immune function
  • Deficiency occurs when fat intake falls below 10% of daily nutrients
  • 1 g fat = 9 cal
• Classification of fats


  • Saturated fats
  • Unsaturated fats
• Saturated fats


  They are usually solid at room temperature and are found primarily in animal products. The liver uses saturated fats to manufacture cholesterol, so excessive dietary intake can significantly raise blood cholesterol levels, especially LDLs. Eating too many saturated fats can lead to obesity, high cholesterol levels, and increased risk of heart disease
• Unsaturated fats


  They are usually liquid at room temperature and come from foods such as nuts, vegetable oil, olive oil, almonds
• Saturated fats


  Usually solid at room temperature
• Sources of saturated fats

  • Dairy items (whole milk, cream, cheese)
  • Fatty meats (beef, veal, lamb, pork, ham)
  • Fat marbling in beef and pork
• Liver


  Uses saturated fats to manufacture cholesterol
• Excessive dietary intake of saturated fats

  Can significantly raise the blood cholesterol level, especially the level of low-density lipoproteins (LDLs), or "bad cholesterol"
• Eating too many saturated fats

  Can lead to obesity, high cholesterol levels, and increased risk of heart disease
• Unsaturated fats


  Usually liquid at room temperature
• Sources of unsaturated fats

  • Nuts
  • Vegetable oil
  • Olive oil
  • Almonds
  • Avocado
  • Peanut butter
  • Corn
  • Soybean
  • Sardines
  • Salmon