Chapter 10: energy balance and weight management

overweight

body weight above a reference range

obesity

chronic, multifactorial disease characterized by excess body fat that may impair health

obesity is associated with higher risk for conditions such as what

hypertension, cardiovascular disease, type 2 diabetes, sleep apnea, osteroarthritis, gallstones, and certain cancers

adipocytes

fat cells

adipose tissues function

store energy, cushions organs, insulates the body, and releases hormones and other signaling molecules

weight stigma

stereotyping, discrimination, or mistreatment based on body weight

three influences on body weight other than personal choices

genes, hormones, and environment

fat-free mass includes what

body water, bone mineral, organs, and protein-rich tissues such as muscle body comp

body composition

the relative amounts of fat-free mass and fat mass in the body

BMI

screening value based on body weight adjusted for height

subcutaneous fat

lies under the skin

visceral fat

surrounds abdominal organs and is more strongly associated with cardiometabolic risk

traditional adult waist-risk cut points for men

greater than 40 in

traditional adult waist-risk cut points for women

35 in

hydrostatic weighing

compares body weight on land while submerged; based on the archimedes principle

DXA

uses low-dose x-ray to estimate bone, lean tissue, and fat

air-displacement plethysmography

uses displaced air in a sealed chamber

bioelectrical impedance

measures opposition to a weak electrical current

skinfolds

measures subcutaneous-at thickness with calipers

energy balance

compares energy intake from foods and beverages with energy output through metabolism, movement, and heat production

energy intake = energy expenditure

energy balance equilibrium

• weight’s stable

energy intake > energy expenditure

positive energy balance

• weight gain

energy intake < energy expenditure

negative energy

• weight loss

resting energy expenditure (REE)

energy used to support basic body functions at rest and usually accounts for the largest share of total expenditure

thermic effect of food averages about what percent of daily energy expenditure

5-10%

what is the thermic effect of food energy used for

digest, absorb, transport, and metabolize food

what is the most variable component of expenditure

physical activity

what usually has the greatest effect on resting energy expenditure

muscle mass

grelin

signal that is released mainly by the stomach and tends to increase hunger, especially before meals

CCK and PYY

released from the intestine after eating and contributes to fullness and stimulate gallbladder contraction

GLP-1

increases glucose-dependent insulin release, slows gastric emptying, and promotes fullness

leptin

released by adipose tissue and signal long-term energy stores tot he brain

insulin

regulates blood glucose and also provides info about available energy

glucagon

supports blood glucose between meals and increase hunger

what does the gene environemtn interaction describe

how inherited susceptible may have different effects in different food, activity, stress, sleep, and social environment

chronic sleep restriction can influence

hunger, food choice, glucose regulation, and opportunities for physical activity

gut microbiome may affect

metabolism

what meals are often more filling

fiber-rich foods, water-rich foods, and adequate protein

set point

concept propsoes that biology and environment can oppose weight

physical activity benefits what

cardiovascular fitness, insulin sensitivity, mood, sleep, muscle and bone even when the scale changes little

what is the most common generic management brand for GLP 1 receptors

semaglutide (Wegovy)

what are the two weight management brands

wegovy and zepbound

older longer-term agents often product about what percentage of total weight loss

5-10%

what is the most common adverse effects of GLP-1 based medicines

gastrointestinal

gastrointestinal symptoms

nausea, vomiting, diarrhea, constiaption, and abdominal cramps

obesity medicines are often used as what treatment

chronic

metabolic and bariatric surgery is recommended by current professional guidelines for many adults with BMI > than what

35

what are the two most common metabolic and bariatric procedures

gastrectomy and Roux-en-y gastric bypass

what do metabolic and bariatric procedures do

reduce stomach capacity and change gut hormones, appetite, glucose regulation, and nutrient absorption

liposuction

removes localized subcutaneous fat for body contouring—not a treatment for obesity

a diet can support weight loss if it

creates a sustainable energy deficit and is nutritionally adequate, and acceptable, and if people can follow it

what does diet composition matter

it affects nutrient density, satiety, lean-mass retention, cardiometabolic health, cost, and long-term adherance

red flags of an unreliable weight loss plan

rapid results, testimonials, special products, ‘melts fat’, excludes foods without a medical reason, discourages medical care