Pbh (nutrition)

• Nutrition


  The science of food and dietary supplements, and how the body uses them in health and disease
• Essential nutrients


  • Proteins
  • Fats
  • Carbohydrates
  • Vitamins
  • Minerals
  • Water
• Digestion


  Breaking down foods into compounds the body can use
• Kilocalorie (kcal)


  The measure of energy in food, 1 kilocalorie is the heat needed to raise the temperature of 1 liter of water 1°C
• 2000 kcal per day typically meets a person's energy needs
• Energy


  The capacity to do work, calories measure energy
• Sources of energy


  • Fat = 9 calories per gram
  • Protein = 4 calories per gram
  • Carbohydrates = 4 calories per gram
• Nutrient density


  The ratio of a food's essential nutrients to its calories
• Food is partially broken down by being chewed and mixed with saliva in the mouth, then further broken down in the stomach and small intestine
• Proteins


  Form parts of muscle, bone, blood, enzymes, hormones, and cell membranes
• Amino acids


  The building blocks of proteins
• Complete proteins


  Provide all essential amino acids, most animal proteins are complete
• Incomplete proteins


  Most plant proteins are incomplete
• Fats (lipids)


  The most concentrated source of energy
• Linoleic acid (omega-6) and alpha-linolenic acid (omega-3)

  Essential fats
• Triglycerides


  Most fats in foods
• Hydrogenation


  Changes some unsaturated fatty acids into trans fatty acids
• Carbohydrates


  Supply energy for body cells, broken down into glucose during digestion
• Glycogen


  A complex carbohydrate stored in liver and muscles
• Dietary fiber


  Nondigestible carbohydrate present naturally, includes soluble and insoluble fiber
• Functional fiber


  Nondigestible carbohydrate that has been isolated or synthesized
• Total fiber


  The sum of dietary fiber and functional fiber
• High-fiber diet can help reduce risk of type 2 diabetes, heart disease, and pulmonary disease and is linked to numerous other health benefits
• Sources of fiber


  • All plant foods
• Vitamins


  Organic (carbon-containing) substances required in small amounts to regulate various processes in cells
• Vitamins


  • Four fat-soluble: A, D, E, and K
  • Nine water-soluble: C and the B-complex vitamins—thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, biotin, and pantothenic acid
• Functions of vitamins


  • Help chemical reactions take place; help unleash energy; produce red blood cells; maintain nervous, skeletal, and immune systems; and act as antioxidants
• Human body does not manufacture most vitamins, they are abundant in fruits, vegetables, and grains
• Certain vitamin deficiencies are associated with health risks, and vitamin excesses can be harmful, even toxic
• To keep the nutrient value in food, store and cook food properly
• Minerals


  Help to regulate body functions and release energy, aid in growth, and maintain body tissues
• Issues may arise if too many or too few minerals, e.g. iron-deficiency anemia, osteoporosis, high blood pressure, heart disease
• Water


  Vital for the human body, which is 50-60% water
• Humans can live up to 50 days without food but only a few days without water, water is used in digestion and the absorption of food and is the medium in which chemical reactions take place
• Antioxidants


  Substances that can reduce the breakdown of food or body constituents by free radicals
• Some antioxidants


  • Vitamins C and E, selenium, and the carotenoids found in yellow, orange, and deep green vegetables
• Phytochemicals


  Substances found in plant foods that may help prevent chronic disease
• Nutritional guidelines and tools

  • Dietary Reference Intakes (DRIs)
  • Dietary Guidelines for Americans
  • MyPlate
• MyPlate


  A food guidance system showing how to use the five food groups at each meal
• Energy intake and portion sizes should be based on an appropriate level of energy intake, and adults with obesity or overweight should shift their eating and physical-activity behaviors to prevent additional weight gain and/or promote weight loss