obesity Flashcards
what are the 2 perspectives of body weight
bmi and %body fat
ideal body weight range in bmi
18.5-25 kg/m2
define obesity/OW
body weight above a standard relative to height
explain the relationship between all cuase mortality and bmi
j shape relationship
low bmi = increased risk mort.
high bmi = increased risk mort
why does high bmi = higher mortality risk?
increased risk for developing diseases
major risk is heart disease
biggest player is hypertension and dyslipidemia
= cvd risk = death risk
but there are diff types of disorders and risk of morbifities depending on disease
examples of conditions that you are greatly increased risk for morbidity when obese
-sleep apnea
breathing issues
t2d, ir
dyslipidemia
galbladder disease
bmi classifications
uw 18.5
normal 18.5 - 24.9
ow 25-29.9
ob1 30-34.9
ob2 35- 39.9
ob3 > 40
which anthro measures DO NOT correlate with fatness?
height
waist: hip ratio
measures for assessment of fatness
wHtR
weight
hip
waist
bai
bmi
weight: height
explain why its important to look at other indictators ALONG with bmi when analyzing fatness
whtr sensitive to risk of cvd
bmi considered some people at no risk but same ppl considered at risk with whtr
you can have a normal bmi but still be at risk with whtr value
value of whtr = increased risk of what?
> 0.5 = risk for obesity related cvd
what is BAI
body adiposity index
=hip circ and height
what to remember about BAI?
not a better measure of adiposity compared to bmi, waist or hip circ
genes that are associated with obesity related traits
BDNF
brain develipment neurotropic factor
BDNF and obesity
bdnf = Appetite regulation via supression
also acts on brain for neuro development
obesity = less bdnf levels and responsivness
why does bdnf have low bioavailablity
short half life
low brain penetration
=via injection solution
define epigenetics
variations in gene expression that are not caused by changes in dna sequences
bi directional relationship bet?
epigenetics and obesity
4 developmental contributors to increasing the risk of obesity + pathways
- maternal preconception body composition = mismatch
- maternal undernutrition = mismatch
- maternal obesity/gd = fetal hyperinsulinimia , more fat cells
- low birth weight = mismatch
- post natal nutrition = apetite control/ preferences
theories of overnutrition
- genetic
- lipostatic
- thermogenetic
- diabetes associated
- psychlogical causation
- thermostatic
- sleep deprivation
thermostatic vs thermogenetic theory
static = dipping below body temp set point = apetite change = h response
genetic = obese = low brown fat cells = less excess energy burning
lipostatic theory
theory of overnutrition
= obese indiv have higher hypothalmic set point
=body fights to bring u back to this range when you step outside of it
=harder to lose weight
pns vs sns in food intake
pns = increase intake
sns = decrease intake
role of hypothalamus
- feeding behaviours
- energy expenditure
- food intake
explain the concept of yoyo diet and body weight set point
see ipad diagram
where is PYY secreted
L cells of ileum, rectum and colon
where is CCK secrted
i cells of small int
where is glp1 secreted
L cells small intes
long term regulators of apetite
insulin
leptin
explain exclusive Breastmilk feeding effects on apetite regulating hormones
BF = apetite supressing nature
less ghrelin, leptin , insulin and pyy
lactose, protein and fat combo = apetite suppressed
good insulin sensitivity
short term regulators of apetite
cck
ghrelin
pyy
how do weight loss surgeries impact apetite regulating hormones?
impacted in how the hormones respond
decreased satiety bc trying to compensate for weight loss
=more ghrelin = less satiety
ghrelin levels post RYGB?
less ghrelin bc loss of parietal cells from stomach
what are some predictors of weight loss?
high:
-bmi
-adipocyte hyperplasia / fat levels
-male
RMR/expernditure levels
early weight loss, counselling, support, goal setting
adipocyte hyperplasia = # fat cells
mechanisms of weight regain
- changes in energy expenditure
- neuroendocrone pathways
- gut physiology
- sibjective apetite
- nutrient metabolism
to maintain weight loss
need behavioral interventions
= diet
= PA
best type of diet to maintain weight loss?
high protein
more low gi foods
3 main counselling approaches to managing obesity
- diet/kcal focus
- food, exercise, beh mods
- hea;thy lifesty;e approach/health @ every size
when assessing an obese indiv, what are some things to remember
-ABCDE
-Assess 4 Ms
assess knowledge
= unrealistic goals.
= pa importance
=diet role and options
how much kcal defecit?
100-200 per day
how many kcal def do u need to burn 1 kg
5000-7000
strategies to reduce kcals in foods
- high intensity non nutritive sweetners
- sugar subs, bulking agents
- more fibre
- fat replacers/reducing energy from fats
example of a fat replacer
olestra
=0 kcal
=replaces function and flavoour of fat
causes gi issues and loose stool tho
example of sugar sub
inulin
polyols
polydextrose
dont really taste like anything so mixed with sweetners, more for sensory properties
weight loss drugs
- pancreatic lipase inhibitors (orlistat)
- saxenda (glp1 agonist)
- metformin
ozempic vs saxenda
ozempic = 1x / wek
saxenda =1 x / day
why dont nasal PYY sprays work for WEIGHT LOSS DRUGS
immune cells block pyy into bloodstream
types of bariatric surgeries?
- adjustable gastric band
- sleeve gastromy
- rygb
- bpd/ds
3 main mechanisms of bariatric surgery
restriction
malabsorption
both
which bariatric surgeries are both restrictive and malabsorptive
rygb
bpd/ds
pre surgical care
assessment
assess defeciences
education - expect, complications, reinforce pa and diet
post surgical care
diet care
long term nutri complications
example of a post surgery nutrition plan
supplements
diet progression
post op diet consists of
slow progression
1. clear fluids
2. full fluids
3. pureed
4. soft
5. solid
proteins = immunity and healing
supplements =malabsorption
long term issues post op
context of rygb and bpd
1. dumping syndrome
2. gallstones
3. nutr defiences
what things slow gastric emptying
slow kcal needs
small meals
more protein and fat
what increases gastric emptying
more cho
solids and liquids
what condition also happens with dumping syndrome
hypoglycemia
