Obesity Flashcards
BMI
weight over height^2 -> normal = 18.5 - 24.9; overweight = 25-29.9
Obesity epi
prevalence is worldwide, ethnic group is a determinant (blacks more obese in US), increasing in children, women > men in US -> prevalence has stabilized in women and possibly in men
Obesity in children
may have stopped rising in many rich nations but trends are still upwards in lower socioeconomic groups to give overall plateau
Overweight
occurs concurrently with underweight in developing countries -> this may divert limited health resources and perpetuate health inequalities
Etiology of obesity
complex and multifactoral -> self environment and built environment -> obesogenic environment and obesogenic behavior (elevators, cars, sedentary lifestyle, cheap high fat food, large portion sizes) -> biological predisposition (22 strongly associated and 127 associated genes) -> positive energy balance (EI>EE) = weight gain
Obesogenic environment
costs of fruit and vegetables have increased while costs of fats and oils, starches and sugars have decreased; Portion sizes 38% larger at a restaurant, females eat more when with males, meals eaten with close friends are larger
Obesity etiology
unlikely to result from impaired metabolism or generalized inactivity -> metabolic rates are HIGHER because they are heavier, measured levels of physical activity are the same as non-obese (may fidget less)
Daily balance error
16 kJ (4kcal), .2% of daily intake/expenditure -> 6 corn flakes/1 minute of walking -> USUALLY UNDETECTABLE
Australian nutrition students
physical activity had no change, energy intake was increased overall (less fats) -> prevalence of overweight in this group was more related to increased energy intake
Thrifty genotype
low metabolic rate and insufficient thermogenesis (Pima Indians -> increases susceptibility to obesogenic environment)
Hyperphagic genotype
poor regulation of appetite and satiety and propensity to overfeed
Sedentary genotype
propensity to be couch potato or physically inactive
Low lipid oxidation genotype
propensity to be a low lipid oxidizer
Adipogenesis genotype
ability to expand complement of adipocytes and high lipid storage capacity
Physical activity
provides the greatest scope of improvement of obesity -> >3 hours of TV doubles exposure, 40% of boys and 50% of teenage girls fail to adequately maintain this -> 60 seconds to consume 300kcal but 60 minutes to expend it
Drive signal
for eating is much stronger (hunger), cessation signal is weaker for physical activity -> bias towards overeating and under activity
Negative beliefs
exercise increases hunger and food intake, exercise is futile for weight loss
Exercise
does not induce an automatic drive in hunger and food intake -> being sedentary does NOT diminish drive to eat and may encourage poor eating habits
1 hour
this much moderate intensity exercise burns 250-300 kcal
Management of obesity
all diets equally effective in practice -> find diet that works best for individual
Carbohydrate exclusion diets
high protein diets are highly satiating, effective way of reducing energy intake -> safe if fruit and veggie intakes maintained, fat quality is appropriate (low in saturates -> canola, olive, fish oil)
Lifestyle clinics
holistic approach aiming to improve overall health -> very expensive -> work as last resort
Orlistat
inhibitor of gastrointestinal lipases: reduces fat absorption from the gut -> SE: fatty stools with possibility of anal leakage
Sibutramine
serotonin and noradrenalin reuptake inhibitor acts centrally to reduce appetite and may have some thermogenic activity -> SE: raised blood pressure, CVD risks outweigh benefits
Needs protein to needs to minimize nitrogen loss
27 year old trauma -> given TPN -> what was the purpose of giving him protein
Kwashiorkor
malnutrition with edema
