Carbohydates

Carbohydates

1. FUNCTIONS

   • 1. ENERGY- glucose oxidised in cells - Broken down in reactions and energy released - good satiety value - 1G=17KJ
   • 2. STORAGE (glucose stored in excess for energy )
     • A. Converted to glycogen (stored in liver and muscles)
     • B. Converted to fat (stored in cells of adipose tissue)
   • 3. PROTEIN SPARING - moderate intake ensures most of protein for growth
   • 4. UNAVAILABLE C. -Adds bulk to faeces and prevent disorders of colon

2. SUGARS

   • INTRINSIC- naturally present/built into cellular structure - Glucose/fructose - No adverse effects on health
   • EXTRINSIC- not incorporated - Maybe from unprocessed foods (lactose) - mainly from processed foods (sucrose) - tooth decay/ dental carries
   • NMES -Sugar other than lactose not within cellular structure -potential to damage teeth - associated with obesity and type 2 diabetes
     • WHY DECREASE INTAKE? -decrease risk of obesity (only provide energy = overweight ) - decrease tooth decay (acid produced by oral bacteria, break down plaque - decrease risk of type 2 diabetes
       • ON CHILD - D. sugars provide substrate for multiplication of oral bacteria/ acid production -acid erodes enamel = demineralisation = tooth decay quicker in children
   • N.SIGNIFICANCE = -provide 'empty calories' (source of energy but NO essential nutrients -large amounts (displace more nutrient dense) - NMES(Damage teeth) - obesity - intrinsic - extrinsic - Increase B.Sugar/pressure/stroke

3. NSP ( decrease to 10%) (12g > 18g)

   • AGAINST DISEASES
     • HEART ATTACK -absorbed NSP=bind and trap Cholesterol -S.NSP= reduce plasma effect (reduce risk)
       • OBESITY - Increase fibre = Decrease Fats /Increase Starch = energy density low = NSP Good satiety
     • BOWEL DISORDER - Increase Volume=Decrease transit time = less pressure to remove contents (good for constipation)
       • DIEBETES - Increase NSP= Increase glucose tolerance -Decrease time of absorption = Decrease time of inulin/glucose in blood
   • -Insoluble cellulose - in cell walls of plants - resistant to breakdown by enzymes in intestine - outer layer of cereal grains (rich source)
     • Soluble - DECREASE Cholesterol/CHD/Diabetes
   • BENIFITS - Dental health - satiety and weight management -slow digestion - Decrease bowel disease

4. COMPLEX CARBOHYDRATES (increase to 50%)

   • NUTRITIONAL BENIFITS = Absorbed slowly (even out blood glucose levels ) -potatoes/ bread - also provide NSP/Iron/Vit B and E - less energy dense/higher satiety than fat
     • E.G BREAD - contains C.C/NSP -Provides iron/calcium -B/E Vitamins -provides other nutrients (protein)
   • -provides other nutrients -good satiety - less energy dense -important energy source

5. GLYCEAMIC INDEX (standard - glucose - 100)

   • Ranking of foods basde on their overall effect on blood gluose levels
     • HIGH GI - quickly absorbed
     • LOW GI-slowly absorbed
       • DECREASE- blood lipids INCREASE -satiety/athletic endurance/B.glucose control

6. DIETARY ADEQUACY OF CARBOHYDRATES = provides energy ( eaten in excess = obesity) - Tooth decay (INCREASE NMES) - C.C are important energy source -C.C Increase satiety - Insoluble = BULKING AGENT - Soluble =Decrease blood cholesterol