Hoofdstuk 8 Flashcards
5 types of chemicals that provide specific nutrients for body functioning
1) carbohydrates (glucose/fructose/sucrose/starch)
2) lipids “fats” (saturated/polyunsaturated/ cholesterol)
3) proteins (amino acids)
4) vitamins (organic) Fat Soluble (ADEK) or water soluble (BC)
5) minerals (inorganic) calcium/sodium/phosphorus/potassium/Iron/Iodine and Zinc
6) Fiber (not used in metabolism, but essential for digestion)
6 Environmental influences food
1) newborns learn from mother
2) availability of certain foods
3) more fast food available, more eaten
4) other people’s response to certain foods
5) portion sizes are often supersized
6) person’s skills to regulate/manage food
Cholesterol
is main dietary culprit in atherosclerosis (deposit of fatty plaques in blood)
- depends on presence of lipoproteins (fats and proteins)
Bad LDL = Low Density Lipids (related to increased plaque deposits)
Good HDL = High Density Lipids (decreased likelihood of plaque build-up)
Triglycerides
fats that increase the risk of heart disease
Omega 3 Fatty Acids = reduce serum triglycerides and raise HDL
Trans Fatty Acids = increase LDL, lower HDL
LDL’s risk depends on 5 other risk factors
-age (45+ men 55+ women)
- cigarettes
- high-risk - much lower LDL
- Low HDL (<40mg)
- family history of cardiovascular disease
- people with low risk should keep LDL below 160 mg
- high risk should be lower LDL
- with heart disease the levels should be below 100mg
Statin drugs greatly lower LDL and raise HDL levels (Crestor/Lipitor/Zocor)
Sodium & Caffeine affect blood pressure
Most effective dietary interventions incorporate or address elements of the theories of health related behavior:
- person’s perceived barriers and benefits of change (Health Belief Model)
- one’s self-efficacy, readiness and intention to change (Stages of Change Model/ Theory of Planned Behavior)
BMI
overweight BMI 25+/ Obese BMI 30+
The body stores excess calories as fat in Adipose Tissue
which increases throughout childhood and adolescence in cell size and cellnumber
Specific genes linked to obesity
FTO - affects the feeling of satiation and causes calories to be stored as adipose tissue rather than burned
MC4R - associated with preferring and consuming high amounts of dietary fat
Set-Point Theory
proposes that each person’s body has a certain (SET) weight that it strives to maintain
- the body tries to maintain its weight near the set-point (with hypothalamus)
- Hypothalamus: monitors the blood for levels of specific hormones (ghrelin/leptin/insulin)
Ghrelin - secreted and carried in the blood to the hypothalamus when energy intake is low or the stomach is empty
- the other 2 hormones increase/decrease in proportion to the amount of body fat the person has
- Leptin regulates circuits in the hypothalamus that stimulate and inhibit eating and metabolism
- Insulin is produced by the pancreas and has a similar, smaller effect on the hypothalamus, but it also regulates the amount of glucose in the blood. The conversion of glucose to fat and the storage of fat in adipose tissue.
- Obsese people tend to have high serum levels of insulin - a condition called hyperinsulinemia - which increases one’s sensations of hunger, perceived pleasantness of sweet tastes and food consumption
- when people lose weight, these hormones signal a need for food (at least a year)
- Ghrelin increase with stress and decrease when stress is reduced
Individuals who develop too many fatcells (fat-cell hyperplasia)
may be doomed to struggle against a high-set-point for the rest of their lives (fat-cells do not decrease)
Research has found higher rates of hypertension/diabetes/CHD and mortality among people with high, rather than low, central adiposity (usually measured as a waist to hip ratio
waist measurement compared to hip measurement
LIfestyle Interventions
designed to modify diet and exercise in overweight people
* nutrition and exercise counselling
* self-monitoring
* stimulus control
* altering the act of eating
* behavioral contracting (rewards system)
- motivation interviewing (cognitive method to use with weight loss programs for commitment and self-efficacy)
- problem-solving strategies (dealing with difficulties)
Medical Approach for weightloss (when obese)
Orlistat: decreases intestinal absorption of ingested fat, produces moderate weight loss and approved for long-term use
Protein-Sparing-Modified- Fast = short term (800 cal)
- Bariatric Surgery (BMI 40+)
1) restricts the holding capacity (band around the upper part of the stomach)
2) surgically creating a small chamber at the top (also modifies the intestine)
Reasons why people, who have lost weight, overeat
1) Biological (hormones keep signalling for food)
2) Lack of reinforcement
3) Existence of food cues
4) negative emotions (Stress/depress)
5) Boredom
- problem-solving training after weight-loss with behavioral methods (self-monitoring stimulus control) = effective in maintaining the loss