1. Introduction to Metabolism

2. Nutrition Defined  Nutrition – the science of foods and the nutrients and other substances they contain and their actions in the body.

3. Science Of Nutrition  From scientific studies come nutritional recommendations.

4. Nutrition Defined  Actions in the body include: Ingestion Ingestion Digestion Digestion Absorption Absorption Transport Transport Metabolism Metabolism Excretion Excretion

5. Metabolism  The total of all the chemical reactions that happen in your body.  Calories consumed  Nutrients needed  Waste produced  Movement within the cell  Chemical reactions to make cell products  EVERYTHING!

6. Nutrition Defined  Nutrients: substances in food that are used in the body for: Energy (calories) Energy (calories) Structural materials (cell membranes, bones, connective tissues) Structural materials (cell membranes, bones, connective tissues)

7. Nutrition Defined  Nutrients: substances in food that are used in the body for: Regulation of body functions (hormones, neurotransmitters) Regulation of body functions (hormones, neurotransmitters) Growth, repair and maintenance of tissues Growth, repair and maintenance of tissues

8. Classifying Nutrients  Essential nutrients – nutrients the body either cannot make or cannot make enough of to meet its needs. These nutrients must be obtained from foods (ingested in some manner) These nutrients must be obtained from foods (ingested in some manner)

9. Classifying Nutrients  Examples of essential nutrients Vitamin CVitamin C CalciumCalcium IronIron 10 of the amino acids10 of the amino acids

10. Classifying Nutrients  Nonessential nutrients – body can make from other nutrients ingested  Examples: CholesterolCholesterol The other 10 amino acidsThe other 10 amino acids

11. Classifying Nutrients  Organic nutrients - contain carbon Carbohydrates, lipids, proteins, vitamins Carbohydrates, lipids, proteins, vitamins  Inorganic nutrients - do not contain carbon Minerals and water Minerals and water

12. Classifying Nutrients  Non-nutrients – substances in foods that do not fit into one of the 6 nutrient categories Examples: Examples: FiberFiber AlcoholAlcohol MedicationsMedications

13. Classifying Nutrients 6 Classes of Nutrients 1. Carbohydrates 2. Lipids 3. Proteins 4. Vitamins 5. Minerals 6. Water

14. Classifying Nutrients  Energy-yielding nutrients (3): Carbohydrates Carbohydrates Lipids Lipids Proteins Proteins

15. Other Recommendations  Recommended intake of energy yielding nutrients 45-65% of caloric intake from carbohydrate45-65% of caloric intake from carbohydrate 20-35% of caloric intake from fat20-35% of caloric intake from fat 10-35% of caloric intake from protein10-35% of caloric intake from protein

16. A little more on energy.  Measure energy in kilocalories in U.S. Kcal = food Calorie = Cal Kcal = food Calorie = Cal What most think of as a “calorie” is really a kilocalorie What most think of as a “calorie” is really a kilocalorie

17. Energy in the Body  The body uses the energy yielding nutrients to fuel all activities Remember, all energy yielding nutrients are caloric. Remember, all energy yielding nutrients are caloric.

18. WARNING: Two graphic slides coming up

19. Energy in the Body  Weight is stable when energy in = energy out  Extra energy taken in is stored for later use This results in weight gain This results in weight gain Manuel Uribe: 570 kg (1,257 lb)

20. Energy in the Body  Weight is stable when energy in = energy out  Inadequate energy intake results in weight loss An anorexic woman

21. Energy-Yielding Nutrients  Carbohydrates: C, H, O 4 kcal/gram 4 kcal/gram Body’s primary source of energy Body’s primary source of energy Use as glucoseUse as glucose Brain’s only source of energy Brain’s only source of energy Stores are limited ~12-24 hours (in liver and muscle) Stores are limited ~12-24 hours (in liver and muscle)

22. Complex carbohydrates (starches) are better for you than simple carbohydrates (sugars) Good sources: whole grain breads, pasta, rice, etc.

23. Energy-Yielding Nutrients  Lipids: C, H, O 9 kcal/gram 9 kcal/gram Body’s preferred alternate source of energy when glucose is not available Body’s preferred alternate source of energy when glucose is not available

24. Energy-Yielding Nutrients High fat foods should be eaten sparingly – Your body can easily make the fats it needs, but fats in food carry some vitamins you need (A, E) Your body can easily make the fats it needs, but fats in food carry some vitamins you need (A, E) Fats can be deposited in your arteries, leading to risk of heart attack, stroke, etc. Fats can be deposited in your arteries, leading to risk of heart attack, stroke, etc.

25. Energy-Yielding Nutrients  Proteins: C, H, O, N 4 kcal/gram (same as _______) 4 kcal/gram (same as _______) Body’s least desirable source of energy because of _____________ Body’s least desirable source of energy because of _____________ Protein is used for energy when fat when carbohydrate stores are empty. Protein is used for energy when fat when carbohydrate stores are empty.

26. Another Use for These Three:  Digestible carbohydrates, proteins, lipids are more than an energy source  They also provide the CHON and monomer building blocks for the body to synthesize (make) its own carbohydrates, proteins, and lipids.

27. Vitamins  Vitamins Organic, but not caloric Organic, but not caloric Classify as water soluble or water insoluble Classify as water soluble or water insoluble  Vitamins serve many functions in the body Help many chemical reactions Help many chemical reactions If they are missing, you become ill If they are missing, you become ill In excess, they can also make you sick In excess, they can also make you sick

28. Minerals  Minerals Inorganic, not caloric Inorganic, not caloric Play many roles in the body Play many roles in the body Some play a structural role:Some play a structural role: calcium in bones calcium in bones Some are dissolved in body fluids as ions:Some are dissolved in body fluids as ions: Sodium, potassium, calcium…. Need proper levels for muscle and nerve contraction Sodium, potassium, calcium…. Need proper levels for muscle and nerve contraction Too high or too low can be dangerous Too high or too low can be dangerous

29. Water  Water (H 2 O) Noncaloric Noncaloric Essential nutrient Essential nutrient

30. RDA Recommended Dietary Allowances RDA is set to meet the needs of 98% of the population (without reaching toxic levels) RDA is set to meet the needs of 98% of the population (without reaching toxic levels) Set at a level that is higher than many needSet at a level that is higher than many need Set at a level that is lower than some needSet at a level that is lower than some need

31. Nutrition Defined  NO NUTRIENT WORKS ALONE Need regular adequate intake of all nutrients for optimal functioning. Need regular adequate intake of all nutrients for optimal functioning. Best obtained from food Best obtained from food Americans with a healthy, varied, diet do not need supplements. Americans with a healthy, varied, diet do not need supplements.

32. Nutrition Defined  If you are getting the vitamins you need from food, vitamin pills just make expensive urine.

33. Nutrition and Health  Nutrition and health are closely related  Chronic health issues associated with diet: Obesity / Anorexia / Bulemia Obesity / Anorexia / Bulemia Osteoporosis Osteoporosis

34. Nutrition and Health  Nutrition and health are closely related  Chronic health issues associated with diet: Type II Diabetes Type II Diabetes Overweight and/or InactiveOverweight and/or Inactive Family history and/or Race ( blacks, Hispanics, American Indians and Asian Americans)Family history and/or Race ( blacks, Hispanics, American Indians and Asian Americans) Age (over 45).Age (over 45). Gestational diabetesGestational diabetes

35. Diabetic Complications  High Blood pressure leading to stroke and kidney failure  High blood fats leading to stroke and heart attack

36. Diabetic Complications  Retinopathy leading to blindness

37. Graphic Images Warning

38. Diabetic Complications  Neuropathy (loss of sensation) leading to Ulcerations / Amputations

39. Improving your Health  Goal is to reduce the number of risk factors that are in your control Risk factor = something that statistically increases the incidence of a disease Risk factor = something that statistically increases the incidence of a disease Risk factors may not be the cause of the disease………Risk factors may not be the cause of the disease………