weight management

obesity

weight that is higher than considered a healthy weight for an individual; typically BMI > 30

BMI categories

underweight: < 18.5

normal: 18.5-24.99

overweight: 25-29.99

obese: > 30

adipose cell proliferation

fats cells increase in number during childhood and adolescence; expand with fat storage and lead to inflammation

adipokine

protein from fat cells that promotes inflammation

lipoprotein lipase

helps store fat by taking triglycerides from the blood into fat cells

- LPL activity is higher in obese people

- after weight loss, LPL activity may increase again

set point theory

the body may fight to return to a comfortable weight after weight loss

causes of obesity

- genetics and epigenetics

- environmental influences

- hormones

-overeating

epigenetics

study of how gene expression changes without altering the DNA

ob gene

codes for leptin, a hormone that regulates body weight

leptin

from fat cells -> suppresses hunger and increases energy use

ghrelin

from stomach -> stimulates hunger (especially when sleep-deprived)

peptide YY

from small intestine -> increases satiety after meals

white adipose tissue

stores fat for energy

brown adipose tissue

releases stored energy as heat

beige (brite) fat

white fat that acts like brown fat; increases with physical activity

obesogenic environment

an environment that promotes excessive calorie intake and discourages physical activity

recommended physical activity levels for health

general: 150 min/week or 30 minutes/day

weight prevention:

60 minutes/day of intense exercise

weight loss medication side effects

GI distress, insomnia, high blood pressure, headaches, dizziness

criteria for weight loss surgery

- BMI > 40 or 35 with health conditions

gastric bypass

bypasses stomach and instantaneous transfer of ingested food to SI

-60-80% weight loss

vertical sleeve gastrectomy

removes 80% of stomach

restricts amount of food stomach can hold

gastric band

band placed around stomach -> limits stomach size

- reduces amt of food stomach can hold

bioliopancreatic diversion with duodenal switch

sleeve gastrectomy

a large portion of small intestine bypassed

- greatest weight loss

healthy weight loss

balanced diet, physical activity, avoiding extreme restriction, behavior change

physical activity benefits

supports weight loss, preserves lean mass, improves mental health

underweight risks

infertility, weak immunity, bone fractures, poor healing

healthy weight gain

eat energy-dense foods, frequent meals, strength training