What are Carbohydrates (CHO)
Sugars, starch, fibre
- Function: energy, fuels brain and nervous system, keep body lean
- CHO rich foods = plants, milk
Three diff types: monosaccharides, disaccharides, polysaccharides (starch, fibre)
What are Monosaccharides
Single sugars
- glucose, fructose and galactose
Glucose
- It’s needed by the brain and NS for energy
- The body must maintain normal BG levels (allow cells to nourish themselves)
Fructose
Fruit sugar, honey, table sugar
- Mostly consumed in soft drinks, cereals, products with high-fructose corn syrup or other added sugars
Galactose
Part of lactose (disaccharide aka milk sugar)
What is Disaccharides
Double sugar (pairs of single sugars linked together)
- Maltose, sucrose, lactose (contain glucose as 1 of single sugars)
Sucrose
- table/white sugar (or brown, powdered)
- glucose + fructose
- occurs naturally in fruits & veg
Lactose
- carb of milk
- born with digestive enzymes to split lactose into 2 monosaccharide (glucose + galactose) -> absorb
- decrease ability to digest lactose after infancy = lactose intolerance
Maltose
- plant sugar
- glucose + glucose
- made when starch breaks down (plants breakdown stored starch for energy -> sprout)
What is Polysaccharides
= complex carbs, long chains of mostly glucose
- glycogen, starch, fibre (fibre broken down into 2 grps, based on chemical and physical properties)
Glycogen
- stored energy (glucose) in liver and muscles
- chains of glucose
- not really consumed via food
Starch
- come from plants
- long chains of glucose (consume plants -> chains broken down into glucose units used for energy)
- food sources: grains, legumes (beans), root vegetables (potatoes, yams)
What are the different types of Fibre
- Fibres
- Soluble Fibres
- Insoluble Fibres
What are Fibres
- Structure in stems, trunks, roots, leaves, skin of plants
- Chains of glucose but can’t break bonds (like in starch)
- They don’t provide energy
- Food Sources: vegetables, fruit, whole grains, legumes
- Are indigestible
What are Soluble Fibres
- Dissolve in water
- Viscous; form gels
- Readily fermented
- Food Sources: barley, oats, legumes, fruit, vegetables
- Role: ↓ risk of chronic diseases
What are Insoluble Fibres
- Do not dissolve in water
- **Not viscous **(don’t form gels)
- Tough, fibrous structures
- ↓ readily fermented
- Food Sources: whole grain, strings of celery, seeds, skin of corn kernels
- Role: aid in digestive system by easing elimination
What role do Sugars and Starches play in digestion and absorption
- Breakdown into smaller molecules (glucose) → body absorbs and use
- Bacteria digest soluble fibres in the large intestine (are intact when passing through the short intestine → large int.)
Identify the dietary recommendation for carbohydrates
- DRI = 45-65% of daily energy from carbs
- RDA = 130 g/day (ex. consume 2000 kcal → 900-1300 kcal from carbs)
- Fibre AI = 21-38 g/day
- 14g of fibre per 1000 kcal
- Choose fibre rich whole grains, fruits and vegetables, legumes
Examine the nutritional treatment of Lactose Intolerance
Lactose intolerance is the ↓ ability to digest lactose after infancy; 75%
- Symptoms include diarrhea, gas, bloating
- Managed by adjusting amount & timing of consumption (are able to tolerate up to 2 cups of milk daily if taken with food)
Treatment includes:
- gradually ↑ intake of lactose foods
- lactase supplements, lactose-free milk
What is Diabetes
↑BG, problems with insulin metabolism
Features of Type 1 DM
Prevalence: 5-10% of cases
Age of Onset: <30 years
Associated Condi: Autoimmune diseases, viral infection, inherited factors
Major Defect: Destruction of pancreatic beta cells; insulin deficiency
Insulin secretion: little to none
Insulin Therapy: YES!
Features of Type 2 DM
Prevalence: 90-95% of cases
Age of Onset: >40 years
Associated Condi: Obesity, aging, inactivity, inherited factors
Major Defect: Insulin resistance; insulin deficiency relative to needs
Insulin secretion: Varies; may be normal, increased, or decreased
Insulin Therapy: Some cases
How do we prevent diabetes
Lifestyle changes
1. Weight Management
- weight loss of at least 7% of body weight for overweight w/ prediabetes
- those who can’t lose weight → avoid gaining more
- Dietary Modifications
- ↑intake of whole grains, fruits, vegetables, legumes, nuts
- ↓intake of refined grains, red meat, sugary drinks
- ↓dietary fat - Physical Activity
- ~150 mins of moderate exercise weekly, ~3x a week - Regular Monitoring
- monitor yearly to check development
What is Glycemic Index regarding DM
- ranking of carbohydrate foods based on effect on BG levels
- ↓GI = ↓glycemic effect; ↑GI = ↑glycemic effect
- choose foods with ↓GI to improve glycemic control (↑fibre, minimally processed over high processed, starchy foods)
