1. Suggestion box
Please me your questions about nutrition-Answers presented following week
on line notes are not complete transcripts of lectures

2. Addition to lecture 2A-
-use a lactose-free dairy product (lactose removed when lactose-free dairy product is made) e.g. some lactose-free milk products are currently available.

3. chicory seed-food additive
-resistant carbohydrate causing decreased pH- due to short chain fatty acid production

4. Questions about diet/exercise records
Project (or essay option)?

5. Lecture 4a- 26 September 2018
CARBOHYDRATES III

6. - sugars in health and disease - complex carbohydrates in health
Overview of lecture 4A
Carbohydrates
- sugars in health and disease
- complex carbohydrates in health
and disease
- where are carbohydrates found
- dietary recommendations
- what’s new and exciting
   

7. Overview of lecture 4a continued
Fibre
Fibre structure and classification and effects
Idatme of fibres
Fibres in health and disease
How to get higher fibre in the diet
   

8. Overview of lecture 4a continued
Recommendations for fibre intake
too much fibre in the diet
Fibres as food additives
What is new in fibre research?
Choosing carbohydrates wisely
Next lecture-4b- Sicko

9. Carbohydrates in health-sugars
Nutrient deficiencies- empty kcal
Dental caries – sugar will cause caries and therefore good oral hygiene important
Obesity – when consumed in excess sugars cause obesity due to conversion of sugar to fat- see next slide first point

10. Carbohydrates in health-sugars continued
Heart disease –lots of refined sugar leads to alterations in blood lipids in carbohydrate sensitive individuals-due to increased insulin response that builds fat
Misbehaviour in children and
criminal behaviour in adults – myth-
nothing to support scientifically these suggestions

11. Carbohydrates in health continued
But sugars in foods are not all bad-many functional properties of carbohydrates
in foods- e.g. taste, physical and chemical properties and antimicrobial purposes
Weight control-foods rich in complex carbohydrate are usually low in fat and added sugars and provide
-less kcal per bite
-also satiety and delayed hunger due to glycemic index issue

12. Carbohydrates in health continued Heart disease
Complex carbohydrate foods also help with
Heart disease
-high complex carbohydrate and low cholesterol diets reduce risk of heart disease
-such high complex carbohydrate and low cholesterol diets are low in animal fat and cholesterol and high in soluble fibres and vegetable proteins

13. Carbohydrates in health-starches continued
Cancer
-lower risk with high complex carbohydrate diet that has loads of green and yellow vegetables and citrus fruit
-nature of preventative effect is not clear
Type 2 diabetes-lower risk with high complex carbohydrate diets-most likely due to such diets being low in fat- also likely due to lower glycemic index issue

14. Carbohydrates in foods
Glucose- e.g. fruits, veggies, honey
Fructose- e.g. fruit and honey
Galactose-rarely in food -mostly in form of lactose
Sucrose-minimal amounts in some fruits and veggies- e.g. beets
Maltose -none naturally in food
Lactose - milk and other dairy products
Oligosaccharides – e.g. inulin – chicory, Jerusalem artichoke
Starch- e.g. potatoes
Glycogen- e.g.- meats little rapid conversion to lactic acid at slaughter

15. DIETARY Recommendations-DRI
Carbohydrates be % of energy
or kcal of carbohydrate or grams of carbohydrate per total energy intake of 2000 kcal/day
-carbohydrates from a variety of sources with increases in complex carbohydrates are recommended

16. DIETARY Recommendations
DRI- Added sugars (simple sugars)-no more than 25 % of calories- but that is 500 kcal or 125 grams (31 teaspoons) of sugars- this is too much
WHO-recommendation

17. Carbohydrates in health-sugars continued
Reducing dietary sugars

18. What is new in carbohydrates? Glycaemic index review by Health Canada
Aziz, A, Dumais, L., Barber J. Health Canada's evaluation of the use of glycemic index claims on food labels. American J. Clin Nutr Aug;98(2): doi: /ajcn Epub 2013 Jun 12.
Nutrition Research Division and the Nutrition Regulations and Standards Division, Bureau of Nutritional Sciences, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, Canada.

19. What is new in carbohydrates?
Aziz et al. American Journal of Clinical Nutrition 98:269-74(2013).
“Health Canada's assessment identified 3 areas of concern with respect to GI labelling:
1)the GI measure has poor accuracy and precision for labelling purposes;
2) as a ratio, the GI does not vary in response to the amount of food consumed and the partial replacement of available carbohydrates with unavailable carbohydrates, whereas the glycemic response does;
3) an unintended focus on the GI for food selection could lead to food choices that are inconsistent with national dietary guidelines. Hence, Health Canada's current opinion is that the inclusion of the GI value on the label of eligible food products would be misleading and would not add value to nutrition labeling and dietary guidelines in assisting consumers to make healthier food choices. “

20. What is new in carbohydrates?
Artificial sweeteners – linked to weight gain and to increased risk of type 2 diabetes- a number of papers
Saccharin changes gut microbiota in mice which in turn contributes to glucose intolerance and hence the risk of type 2 diabetes
Nature 514, 181–186 (09 October 2014)

21. Fibre structure and classification and effects
Insoluble
Cellulose-bran,vegetables
Hemicellulose-bran, whole grains
Lignins-fruits, mature vegetables, flax
Generally-accelerate gi transit,
-increase fecal weight(promotes bowel movements)
-slow starch digestion,
-delay glucose absorption
-but can be exceptions

22. Fibre structure and classification and effects continued
Soluble
Pectins-apples, carrots, gums and mucilages- oats, legumes
Generally-delay gi transit,
-delay glucose absorption,
-lower blood cholesterol
-but can be exceptions

23. Other fibre functions (classifications)
- water holding capacity
viscosity
cation exchange capacity
bile binding capacity
fermentability

24. Fibre ingestion, digestion, absorption and transport, metabolism, excretion
mouth for ingestion
fibre not digested in mouth or stomach or by small intestine enzymes-why?
bacteria-make short chain fatty acids and gas
short chain fatty acids and water absorbed at large intestine
and transported by blood used for energy (fatty acid metabolism
next week – lecture 5A), water can split molecules to release energy
Excretion- gas exits anus, undigested fibre leaves in faeces, water excreted via faeces, urine, sweat, saliva?, and breathing)

25. Fibre in health and disease
weight control
-bulk-less appetite
-soluble and insoluble fibres
heart disease
-soluble fibres lower cholesterol (bile issue)
-fibre may displace fat in diet

26. Fibre in health and disease continued
Cancer
Lower colon cancer-fibre may help by diluting and binding and more rapid excretion of carcinogens- both soluble and insoluble fibre may help
Breast cancer
-secoisolariciresinol diglucoside (SDG) is a mammalian lignan pre-cursor that is found in flaxseed-SDG is not a fibre but is found in the fibre region of flaxseed
-metabolites of SDG are mammalian lignans which are produced by bacteria in the large intestine- these mammalian lignans may reduce breast tumour growth in humans)

27. Fibre in health and disease continued
Diabetes
control weight-diabetes
slow glucose absorption-glucose surge
soluble fibres are key here

28. How to get higher fibre in the diet
Fibre content
High Medium Low
5g 2 g g
Breads cereal
Rice Group
Breads Whole wheat white
1 slice bread bread
Cereal All Shredded Rice
½ cup bran Wheat Krispies
Pasta whole macaroni
½ cup wheat pasta

29. How to get higher fibre in the diet continued
Fibre content
High Medium Low
4 g 2 g 1 g
Fruit group
1 MEDIUM
OR ½ CUP berries apple melon

30. How to get higher fibre in the diet continued
Fibre content
High Medium Low
4 g g 1 g
Vegetable
Group
½ cup peas green asparagus
beans

31. Remember that: fibre from natural sources rather than commercially
prepared fibre is better because foods contain vitamins and minerals as well as the fibre

32. DRI recommendation for fibre intake
follow DRI recommendations for carbohydrate intake and this will
provide sufficient fibre
DRI - 14 grams fibre/1000 kcal (roughly grams of fibre/day)
(no distinction between soluble and insoluble but variety is the key to balance)

33. Too much fibre in the diet gives:
flatulence
obstruct gi tract if greater than 50 g fibre /day
top recommendation is 40 g/d for adults (who)

34. Too much fibre in the diet continued
insoluble fibre has phytates that can bind minerals- e.g. calcium, iron, zinc and magnesium
prevents enzyme contact

35. Too much fibre in the diet continued
increases volume of food required to meet energy requirements
satiety before adequate nutrition-generally only a problem if diet low in micronutrients or in small children (small stomachs)

36. Too much fibre in the diet continued
-important to increase water intake with increases in dietary fibre
-otherwise constipation but if have enough water can get diarrhea (bacterial breakdown of fibre)

37. Fibres as food additives
pectin -common in fruits and vegetables
-forms gel when sugar and acid added
-commercially from citrus peels and apples
-thickening agent in jams, jellies and tomato paste

38. Fibres as food additives continued
-carbohydrate gums- used and thickeners and stabilizers
because they combine with water to keep solutions from
separating
-used in gravies, pie fillings, jellies and puddings

39. Fibres as food additives continued
gums derived from gum arabic, gum karaya, guar gum, locust bean gum, xanthan gum and gum tragacanth
gums extracted from shrubs, trees and seed pods

40. Fibres as food additives continued
pectins and gums are used in reduced fat products to mimic the texture and viscosity of fat

41. Fibres as food additives continued
other thickening agents and stabilizers are from seaweeds
( e.g. agar, carrageen and alginates)

42. What’s new in fibre research?
Oligosaccharides now considered fibre (used to be that fibre was only in polysaccharide form)
Oligosaccharides (e.g. inulin which is found in chicory and Jerusalem artichoke for example, can promote growth of good (for health) bacteria in the large intestine (please note that inulin is a pre-biotic and the bacteria are called pro-biotics)
Slavin, J. Nutrients 5: (2013)

43. How to choose carbohydrates wisely
1)increase intakes of whole grains
2)use whole grain products such as oatmeal,
brown rice and whole wheat bread
3)increase consumption of legumes such as
kidney, black and pinto beans)if fresh fruits
not available, choose frozen or canned fruits without added sugar

44. How to choose carbohydrates wisely continued
4)use whole grain flour for
¼ to ½ the amount of flour in the recipe
5)use less sugar in baking
6)use less added sugars in foods
7)eat fewer high sugar foods
8)use food labels to guide one’s choices