Unit 9: Nutrition

1. Unit 9: Nutrition

2. Nutrition Overview • Nutrition supports tissue growth, repair, function • Digestion: process of breaking down food into smaller and smaller pieces so we can eventually absorb the nutrients from it • Starts in the mouth: enzymes/chewing • Continues in stomach: hydrochloric acid • Finishes in small intestine: enzymes

3. Digestion

4. Nutrition Overview • Metabolism: the sum of all the chemical reactions in your body. • Building it up (anabolism) and breaking it down (catabolism) • Main location = liver • Nutrition: “the act or process of nourishing or being nourished” • Diet: “food and drink regularly provided and consumed”

5. Main categories of nutrients • Fats • Carbohydrates • Proteins • Vitamins • Minerals • Water Provide energy The most vital nutrient

6. Major Categories Nutrients • Carbohydrates: metabolized to simple sugars like glucose, a ready source of energy that circulates the body • Provide 4 kcal/ g of energy • Ex. Pastas, breads, fruits and vegetables

7. Major Categories of Nutrients • Fats: essential parts of cell membranes and some hormones. Provide insulation to warm body. • Provide 9 kcal/g of energy • Ex. Canola oil, butter, meat fat

8. Major Categories of Nutrients • Vitamins: organic compounds our body needs to function normally that it must obtain from the diet because it can’t make them itself

9. Major Categories of Nutrients • minerals: a naturally occurring solid compound found on the periodic table • They support Biochemical processes • Both vitamins and minerals provide 0 kcal/g

10. Water • Most essential nutrient • Human body ≈ 60% water by weight (depending on size) • Many body processes require it • Maintains blood pressure • Readily available from beverages and fruits/vegetables

11. Proteins • Mostly responsible for growth and repair of tissues. • Provide 4 kcal/g of energy. However, are only really used for energy when everything else has been used up

12. Protein • Made from amino acids • The body can make most amino acids except for a few (9) which are essential amino acids (EAA). • We have to get them from our diet! • Proteins from plant foods are “incomplete” meaning that they only contain some EAAs but not all • But two incomplete proteins together may make a complete protein = complementing amino acids

13. Modern North American Diet • Biggest problem = nutritional excess • Affluence? • Convenience foods? • Perceived shortage of time?

14. Modern Canadian diet

15. Modern North American Diet • Getting too much of everything and in the improper proportions • Too much saturated fat • Half of carbohydrates from baked goods • 65% of B. Columbians not eating recommended amounts of fruits and vegetables • 77% not eating recommended amounts of calcium. • However, we are concerned about our fat, starch, fibre intake and are taking steps to fix it (especially women)

21. 6 Principles of a Healthful DietABCD-MV • Adequacy- are you getting enough of what you need? • Balance- getting a good balance of all food groups • KiloCaloriecontrol- are your energy consumption patterns matching your expenditure ones • Nutrient Density- for the amount of kilocalories you are taking in, are you getting a good amount of nutrients? • Moderation-not too little or too much of anything • Variety- a range of food items from each food groups

22. Nutrient Density

23. Dietary Goals for North Americans

24. Reduce total caloric intake • One Calorie (as we know it)= 1,000 calories = 1 kcal • The key is to eat selectively, portion control • Buy smaller plates • Think of restaurant meals as 2 meals • Consume nutrient dense foods • Control hunger by consuming filling foods such as protein/fibre, eating smaller meals throughout day • We consume, on average, 18% more calories a day than 30 years ago

25. Reduce total fat intake • Fat is associated with higher calorie intake as well as increased serum cholesterol • Associated with some forms of cancer: breast, colon • Often it’s not the original source of food that is high in fat, but the manner in which it is prepared • Cut fat off meat before cooking, choose low fat cheeses/spreads, dab extra fat off pizza, avoid friend foods, fill a spray bottle with oil to grease pans, BBQ, broil, bake

26. Reduce proportion of saturated fat and increase the proportion of unsaturated fat • Saturated fat = solid at room temperature ( ex. Bacon fat). • Animal fats typically high in saturated fat, while plant fats are typically low in saturated fat • However, palm-oil/ coconut oil = high in saturated fat • Unsaturated fat typically found in plant oils • Is actually “good fat” • Fish oil is one of the best kinds because it also has omega-3 fatty acids and reduces the risk of CVD

27. Choose a diet low in cholesterol • Found mainly in animal products • Eggs, liver, kidney, shellfish all high in cholesterol • However, dietary cholesterol only raises serum cholesterol if the person is sensitive to dietary cholesterol • Recall: for most individuals to lower serum cholesterol, they need to consume a diet low in _______________

28. Increase Dietary Fibre • Fibre = is a carbohydrate that we are not able to break down in our body to use for energy • It is “filler”, passing through the digestive tract without being absorbed. • Add bulk to your diet, thus possibly reducing appetite

29. Increase Dietary Fibre • Soluble fibre: • Lowers total and LDL cholesterol • Regulates blood sugar • Ex. Fruits, legumes and oats (oat bran) • Insoluble fibre: • draws water into the stool making it larger and softer • Speeds passage of food through the digestive tract • Ex. Cereals, grains (wheat bran), vegetables

30. Increase consumption of complex carbohydrates • Complex carbs are found in grains, cereal, pasta and potatoes • Take longer to absorb than simple carbohydrates (ex. Glucose, fructose) • Therefore regulate blood glucose levels, which is preventative against __________________ • Contain more dietary fibre, richer sources of vitamins and minerals • Look for “100% whole wheat”, “whole grain”, “whole oats”, “whole rye” on labels. Just because something says “whole wheat” doesn’t mean it is a complete whole grain. Check you labels!

31. Use Salt and Sodium in Moderation • Table salt = sodium chloride • North Americans typically consume more than 3 times the RNI for sodium! • Sodium is added to a lot of products upon processing • Sodium may increase blood pressure, which can cause a __________ in an artery leading to _______________ • Salty foods are a risk factor for some digestive cancers • Irritates cells lining the stomach

32. Ensure adequate iron intake • Iron deficiency can lead to anaemia, which is a lowered ability of the blood to transport oxygen • Leads to decreased energy levels

33. Ensure adequate iron intake Two forms of iron: • Heme iron from animal products. Ex. Beef, liver, heart • Easier to absorb • Non-heme iron from plants. Ex. lentils, beans • Not as easy to absorb into digestive tract • Absorption of non-heme iron is improved if eaten together with a heme-iron source • Overall, Iron absorption improved by vitamin C, inhibited by coffee/tea

34. Ensure adequate Calcium intake • Many vital processes in your body require calcium • Also a major component of bones/teeth • Prevents osteoporosis, which is especially relevant to post-menopausal women • Smoking has the opposite effect of calcium!

35. Increase consumption of foods containing vitamins A and C • Vitamins C / A (beta-carotene) are powerful antioxidants • An antioxidant prevents the action of oxidizing agents in the body that damage cells and can lead to cancer (as well as aging poorly) • Increase consumption of dark orange and dark green veggies • Cabbage family veggies (arugula, bok choy...) are especially good anti-oxidants

36. Drink Alcohol in moderation • Contains 7 kcal/g (more than carbs and proteins!) • One regular beer = 150 kcal • One glass white wine = 100 kcal • One shot of vodka = 60 kcal • “empty calories” • Alcohol should NEVER be consumed during pregnancy!

37. Eat a variety of foods • That way if some foods aren’t providing you with the nutrients you need, others will • Eliminates boredom!

38. Vegetarian Diets • Do not contain meat • Types of vegetarians: • Vegans: eat NO animal products of any kind; this includes milk. • Lacto-ovo-vegetarians: don’t eat fish but eat milk products and eggs • Lacto-ovo-pescovegetarians: don’t eat red meats but eat fish, milk, eggs • Not really vegetarians!

39. Health Benefits of a Vegetarian diet • Prevents/ reverses coronary artery disease • Lowers serum cholesterol and LDL • Lowers incidence of hypertension • Lowers mortality from type 2 diabetes • Lowers incidence of lung/ colorectal cancer • May decrease breast cancer and kidney damage

40. Other Benefits of Not Eating Animal Products • Animal products tend to be expensive • Protein rich diets may be high in fat, low in fibre • Meat/ dairy more likely to contain pathogens • Animals concentrate heavy metals such as mercury in large fish • Better use of land resources

41. Nutrient Deficiencies associated with the vegetarian diet • Typically eat less protein, however, it is often enough • Iron is harder to absorb from plant food • B-12 • Calcium • Vitamin D

42. Reading Labels • As of Dec 2007, all manufacturers had to conform to new and extremely strict labelling standards in Canada. • New labels contain: - The common name of the food - A net quantity declaration - The name and address of the dealer - The durable life date of the product - A list of ingredients (in decreasing order by weight, volume, count - A nutrition facts table (next slide) • They can also contain: • Nutrient content claims– ex. ‘low in fat’; ‘reduced sodium’ • Health claims– ex. “a diet low in saturated fat is associated with decrease incidence of heart disease. Product X is low in saturated fat

43. Nutrition Facts Table • All labels in Canada must contain the following information • Nutrients expressed in %Daily Value for ease • Check to make sure the serving size matches how much you are consuming!

44. Nutritional concerns of the developing world

45. Water • People need approximately1 litre water/ day to survive • In the third world, 1/3 people have access to clean drinking water • Estimated that 17-25 diseases relating to water could be reduced by 50-100% with ample clean drinking water

46. Energy and Protein • Lack of calories and protein impairs growth • Small females have more difficulty carrying/having children • Lack of calories and protein increases susceptibility to disease • Our immune cells need energy/protein to function! • Malnutrition often a contributing cause of illness • Ex. measles

47. Nutrient Deficiency: Kwashiorkor • Another important function of protein is to maintain water balance • Lack of protein leads to fluid accumulation in the abdomen

48. Obesity in the third world • As standard of living increases, so do obesity rates • Egypt, Mexico have very high rates of childhood obesity • Both have a stable and growing economy