AA

Nutrition/Metabolism Part 1

Nutrition and Health

  • nutrition- composition and quality of food intake and the utilization of food by a living organism
  • How does your body use nutrients from your diet?
    • energy- biochemical reactions release the energy in carbohydrates, lipids, and proteins
    • building blocks for structures- this is how lots of proteins, nucleic acids, and lipids get used
    • regulation of body processes- all chemical reactions in the body (metabolism) are regulated to create a stable environment that is said to be in homeostasis
  • malnutrition- when the organism is not receiving the optimal amount of nutrients to be healthy
    • undernutrition- inadequate supply of nutrient amount or type
    • most organisms are thought to live in an undernourished state- on the edge of starvation
    • overnutrition- plenty of nutrients in amount and type
    • tends to be in humans in developed countries
  • optimal nutrition- amount and type of nutrients in the diet designed to increase health and longevity

Cardiovascular Disease and Health Disparities

  • heart disease is the leading cause of death for men & women as well as people of most racial & ethnic groups in the US
  • 1 person dies every 37 seconds from cardiovascular disease in the US
  • about 647,000 Americans die from heart disease each year- 1 in every 4 deaths
  • heart disease costs the US about $219 billion each year from 2014 to 2015
    • includes the cost of health care services, medicines, and lost productivity because of death
  • 7 things that contribute to heart disease- smoking, BMI, physical activity, diet, total cholesterol, BP, diabetes
  • children (ages 12-19) tend to be okay in all categories except diet, physical activity, and BMI
    • children have increased consumption of energy-dense, nutrient-poor foods
    • children also have lower physical activity now
    • unhealthy diets + lack of physical activity = increased BMI and risk of obesity
  • adults carry over these bad diet practices from childhood
  • 10 dietary factors of cardiovascular disease
    • low intake of fruit
    • low intake of vegetables
    • low intake of nuts/seeds
    • low intake of whole grains
    • low intake of seafood omega-3 fats
    • low intake of polyunsaturated fats
    • high intake of sodium
    • high intake of unprocessed red meat
    • high intake of processed meats
    • high intake of sugar-sweetened beverages
  • proportion of younger people (ages 25-54) dying because of cardiometabolic disease higher because younger people shouldn’t be dying of cardiovascular disease
  • proportion of african-american people dying because of heart disease higher than proportion of white people
    • mainly due to social determinants of health
  • main comorbidities of COVID- heart disease & diabetes

Energy Density and Oxidative Metabolism

  • energy-dense/nutrient-poor foods- foods that have high caloric content with very other little nutrients

  • carbs and fats are broken down via metabolic processes and converted to adenosine triphosphate- the body’s energy currency

  • ATP has three phosphate groups with 2 high energy phosphoanhydride bonds and a lower energy phosphate ester bond linking the adenosine and the alpha phosphate

  • ATP is then used to fuel any mechanical work or process that requires energy input

  • calorie- the amount of energy required to increase the temperature of 1 g of water by 1 degree C

    • different than the Calorie/kilocalorie- 1000 calories

  • amount of kcal/g in each macronutrient

    • fats- 9 kcal/g
    • alcohol- 7 kcal/g
    • carbohydrates- 4 kcal/g
    • protein- 4 kcal/g

  • compounds are broken down for energy by oxidative metabolism- which is why we need oxygen

    • taking carbons in a compound from a reduced state where they have more electrons assigned to them to a compound where they are in an oxidized state with fewer electrons assigned to them

  • assign the central carbon 2 electrons per bond if bonded to a hydrogen, 1 electron per bond if bonded to another carbon, 0 per bond if bonded to oxygen

    • this is because H < C << O in terms of electronegativity

    Reducing the number of electrons assigned to the central carbon via oxidative metabolism

  • the above reactant compound is actually the first part of a fat

    • so fats have more energy per g because they have high reduction potential

  • carbohydrates and proteins are already partially reduced because they have carbons bonded to oxygens

    • alcohols are somewhat in between carbohydrates/proteins & fats because they have a hydrocarbon portion bonded to an OH group

Types of Fats

  • different types of fats
    • saturated fats- fats where all the carbons have as many hydrogens bonded to them as possible
    • higher melting point, solid at room temperature, mostly animal fats
    • unsaturated fats- fats that have at least one double bond within the carbon chain
    • lower melting point, liquid at room temperature, mostly plant fats
    • monounsaturated- only 1 double bond
    • polyunsaturated- have many double bonds
    • cis fats- have “kinks” in the carbon chain
    • the parts of the carbon chain are on the same side of the double bond
    • lower melting point because they can’t all line up
    • trans fats- look like saturated fats
    • the parts of the carbon chain are on opposite sides of the double bond
    • formed by partial hydrogenation- reaction where polyunsaturated fatty acids get hydrogens attached to them to make them more saturated
      • makes margarine
  • saturated and trans fats are associated with increased blood cholesterol