Nutrition Basics: Macronutrients Carbohydrates

1. ]]Describe the 3 functions that nutrients play in the body.]]
   • Provide energy; biochemical reactions release the energy contained in carbs, protein and fat
   • Form structures; water, protein and fat are the must abundant nutrients in our body. Together with minerals, they form and maintain the shape/structure of our body
   • Regulate metabolic body processes
2. ]]Define acceptable macronutrient distribution range and know the range for each macronutrient.]]

==Dietary reference intakes (DRI)==

• Recommended dietary allowance (RDA) - intakes sufficient to meet the nutrient needs of almost all healthy people in a specific life stage and gender group
• Adequate intake (AI) - when RDA does not exist
• Tolerable upper intake level (UL) - max daily intake that is unlikely to pose a risk

==Acceptable macronutrient distribution range (AMDR)==

• The range of intake for a particular energy source (carb, protein + fat) that provides adequate energy and nutrients and reduces the risk of chronic disease
• expressed as a % of total energy (kcal)
• %%Carbs: 45-65%%%
• %%Proteins: 10-35%%%
• %%Fats: 20-35%%%

1. ]]Explain the classification of carbohydrates.]]

   • Monosaccharides
   • Disaccharides
   • Polysaccharides
   • All carbs are converted to ^^glucose^^ (major energy source) - only energy source the brain can use
   • Excess glucose is stored as ^^glycogen^^ mainly in the liver, muscle, and as fat

2. ]]Compare and contrast simple vs complex carbohydrates, including their: role in the body and food sources.]]

   • ==Simple (sugar)==
     • %%Monosaccharides%% - single sugar
     • glucose, galactose, fructose
     • water soluble
     • %%Disaccharides%% - pair of monosaccharides
     • Lactose (glucose + galactose)
     • Maltose (glucose + glucose)
     • Sucrose (glucose + fructose) - table sugar
     • Healthy simple sugars: fruit, milk, milk products, vegetables
     • Not so healthy: processed and refined foods, candy, pop, table sugar, syrup
   • ==Complex==
     • %%Polysaccharides%%
     • contain hundreds to thousands of monosaccharide chains (mostly glucose units)
     • 3 kinds:
       • In plants called ^^starches^^ and ^^fiber^^ (soluble and insoluble)
       • In animals called ^^glycogen^^ (note: not a dietary source of carbohydrates)
     • Role of complex carbs:
     • %%Glycogen%%
       • Storage form of energy (glucose) in the body
       • Storage sites: liver and muscle cells
       • Yield energy
     • %%Starch%% ^^(main food source of energy)^^
       • Storage form of energy (glucose) in plants
       • Yield energy
       • Healthy: grains (wheat, rice, couscous, millet, rye, barley); root/tuber plants (yam, potatoes); and legumes (peas, beans)
       • Less healthy: refined or processed foods (e.g. white bread, white rice, regular pasta - anything made with white or all-purpose flour)
       • provide quick energy but little nutrition (unless enriched)
     • %%Fibre%%
       • Provide structure in plants - yield little energy
       • Bonds can’t be broken by human enzymes
       • ^^Unavailable carb^^ because produces no energy

3. ]]Describe suggested maximum sugar intake (Health Canada) and describe what is meant by “added sugar”]]

   • Health Canada: %%<= 25%%% of total daily calories should come from added sugars
   • Added sugars - supply energy but have no nutrients
     • Syrup, pop, candy - handled the same way as naturally occurring sugars (e.g. fruits, milk, honey)
     • Contribute to tooth decay
     • Diets high in processed food (refined carbs) and low in fibre lead to dysbiosis (imbalance of gut flora)

4. ]]Discuss the benefits of using sugar substitutes and identify which ones are considered safe for use in pregnancy.]]

   • Less calories than sugar (may assist in weight control)
   • Less effect on blood sugars (useful in diabetes)
   • Safe in pregnancy:
     • No rigorous studies
     • Based on history of use: %%acesulfame, aspartame, and sucralose%% are considered safe

5. ]]Explain the health benefits of insoluble and soluble fibre and provide a food source for each.]]

   • %%Soluble fibre%% - dissolves in water turns into gel (viscous) - slows digestion; fermentable
     • Oats, barley, flax seeds, seeds, beans, lentils, peas, some fruits (apples, oranges, pears, strawberries, blueberries), psyllium, some vegetables (celery, carrots)
   • %%Insoluble fibre%% - does not dissolve in water but becomes bulkier - increases fecal bulk; speeds food transit through stomach, intestines; non-viscous, less readily fermentable
     • Whole wheat, whole grains, wheat bran, corn bran, seeds, nuts, brown rice, fruits, vegetables (cabbage, broccoli, etc.), root vegetable skins
   • Health benefits:
     • Lowers risk of heart disease: lower BP, improve blood lipids, reduce inflammation → diets high in whole grains and soluble fibre
     • Lower risk of diabetes: high soluble fibre foods can reduce risk of Type 2 diabetes → slows down glucose absorption
     • Alleviate constipation: insoluble fibres (e.g. seeds, nuts, whole wheat) increase fecal weight and speed passage through the colon

6. ]]Explain the difference between wheat flour and whole grain flour.]]

   • %%Wheat flour%% - any flour made from the endosperm of a wheat grain

     • also known as refined flour
     • Is generally enriched: has iron, thiamin, riboflavin, niacin, folate added

   • %%Whole grain%% - made from the entire kernel of a cereal grain (e.g. quinoa, whole wheat, rye, oats, corn, brown rice, wild rice, whole grain pasta)

     • Bran (outer coating of wheat kernel; rich in fibre)
     • Endosperm (mainly starch, some protein)
     • Germ (seed-rich in vitamins and minerals)

     

7. ]]Discuss the glycemic index.]]

   • %%Glycemic index%% - a scale that ranks carbohydrate-rich foods or drinks by how much (and how quickly) they raise blood glucose levels compared to a standard food (glucose or white bread)
   • Low GI diet can help decrease risk of T2DM (lower HbA1c), heart disease, stroke; feel full longer; maintain or increase weight loss
   • Combining carbs with fats and proteins will change how fast the food is absorbed