Nutrition Lecture 10 - weight management

Lipoprotein Lipase (LPL)

an enzyme mounted on the surface fat that hydrolyzes triglycerides in the blood into fatty acids and glycerol for absorption into the cells. they are metabolized or reassembled for storage

High LPL activity = more efficient at storing body fat

Leptin

produced by fat cells

decreases appetite

increased energy expenditure

leptin resistance = obesity

Ghrelin

hormone that stimulates appetite and promotes efficient energy storage

released by stomach when empty

works on hypothalamus

increases hunger, smell sensitivity

lean people have high levels, obese people have low levels

what happens to fat cells during obesity

fat cells increase in size and often in number with increased fat storage

compared to healthy-weight people, obese people have

more fat cells

larger fat cells

set point theory

theory that body maintains a certain weight by means of internal control

idea that body weight is physiologically regulated

decreased metabolic rate with weight loss

microbiome

bacteria in GI that communicate with ‘host”

unfavorable bacteria may negatively impact health, energy balance, and metabolism

dysbiosis

alteration of microbiome to unhealthy balance

what are some characteristics of the obesogenic environment

external factors that encourage increased intake and reduced physical activity

obesogenic environment factors include

overeating, learned behavior, physical inactivity, built environments (lack of sidewalks or bike lanes, safe parks additionally food deserts with low-income and therefore energy dense and nutrient deficient foods)

inappropriate treatments for obesity

over the counter weight loss products (pills, powders, supplements)

other gimmicks (steam/sauna, wraps, creams etc.)

sibutramine

aka meridia

suppresses appetite

not available in the US due to increased risk of heart attack

phentermine

suppresses appetite

increase BP and heart rate

orlistat (Xenical and Alli)

inhibits fat absorption

diarrhea, gas, reduced fat-soluble vitamins)

a candidate for weight loss surgery includes

someone with a BMI of greater than 40 or a BMI of greater than 35 with related health conditions

Roux-en-Y Gastric Bypass (RYGB)

-most common

-gold standard

-instantaneous transfer of ingested food to the small intestine

Advantages:

-loss of 60-80% of excess weight

-restricts amount of food consumed

-favorable hormone changes

-typical maintenance of weightless

Vertical Sleeve Gastrectomy (VSG)

-nicknamed the sleeve

-removes approx.. 80% of the stomach

Advantages:

-restricts stomach capacity

-rapid weight loss (comparative to RYGB)

-no foreign objects, no bypass, shorter recovery

-favorable gut hormone changes

Adjustable Gastric Band (BAND)

-inflatable band placed around upper portion of stomach

-reduction occurs gradually overtime with repeated adjustments

Advantages:

-reduces amount of food stomach can hold

-reversible and adjustable

-very short hospital stay (no cutting of tissue)

-lowest risk for vitamin/mineral deficiencies

Biliopancreatic Diversion with Duodenal Switch (BPD/DS)

2 components:

-sleeve gastrectomy

-portion of the small intestine bypassed

Results in significant decrease in nutrient absorption

Advantages:

-greatest weight loss (60-70% excess weight at 5 years follow up)

-reduces fat absorption by >70%

-favorable changes in gut hormones

-most effective against diabetes

what is a reasonable goal for weight loss

5-10% weight over ½ year and sustained

Describe characteristics of successful weight loss strategy

-small changes

-moderate losses

-reasonable goals

-nutrient-dense foods

-regular physical activity

define disordered eating

abnormal and potentially harmful eating behaviors that DO NOT meet specific criteria for an eating disorder

possible components of a healthful eating plan for weight loss

replace energy-dense with nutrient dense foods

aim for loss of 1-2 lbs per week

fruits, vegetables, legumes, whole grains

control portion size (use smaller plates, bowls, glass)

limit sugar

Anorexia Nervosa

self-starvation and excessive weight loss

intense fear of gaining weight or being fat

distorted sense of body image

fear of certain foods

may exercise excessively

Bulimia Nervosa

binge eating and purging (vomiting, excessive exercise, abuse of diet pills, laxatives, diuretics)

Anorexia Nervosa health consequences

-highest mortality rate of any psychiatric disorder

-common to experience electrolyte imbalances (irregular heart rate and possible heart failure)

-body begins to shut down some processes in an effort to conserve energy

decrease in heart rate, blood pressure, constipation, bloating, delayed gastric emptying, decreased body temperature

Laungo: fine downy hair on arms and fact that results as an effort to maintain body heat

Bulimia health consequences

vomiting for purging = tears in esophagus, swollen parotid glands, tooth decay, gum disease, broken vessels in eyes

electrolyte imbalances

dehydration

constipation

Russell’s Sign = scar tissue on knuckles of fingers used to induce vomiting

Binge eating disorder

characterized by recurrent episodes of binge eating without purging

health concerns of binging

high blood pressure

high cholesterol

cardiovascullar disease

type 2 diabetes

gallbladder diease

joint problems

depression

other specified feeding or eating disorders

disordered eating patterns and behvarios that do not meet specific criteria for other eathing disorder diagnosis

associated with reduced ability to engage in social interaction and inability to perform work at expected level

examples of other specified feeding and eating disorders

atypical anorexia nervosa (weight is at or above normal range)

bulimia nervosa of low frequency or limited duration (<1 episode per week, duration < 3 months)

binge eating disorder low frequency and or limited duration (<1 episode per week, duration < 3 months)

common signs of disordered eating

hair loss, weight changes, Russell’s sign, avoidance of social interactions

men account for _____ reported cases of EDs

approx. 10%