Chapter 10 - Energy Balance Flashcards
Define energy
ability to do work
Define energy intake
total energy consumed from food
Define energy expenditure
energy used t fuel basal metabolism, physical activity, processing food
Define energy balance
when energy intake = energy expenditure
Energy expenditure
We burn energy for three main purposed
- Basal metabolic rate (~60-75%)
- Diet-induced thermogenesis (~10%)
- Physical activity (~15-30%)
Basal metabolic rate (BMR)
the amount of energy the body needs to perform its most basil life-sustaining functions over a period of time
What factors determine BMR
higher BMR
- certain genetic factors
- male sex
- younger age
- taller height
- higher lean body mass
Diet-induced thermogenesis
energy that is used and dissipated as heat following food intake
Weight gain
Occurs due to an increase in:
- fat mass ( consistent energy surpluss)
- Lean mass ( increased muscle mass)
- water mass (can fluctuate from day to day)
- glycogen storage
Adipocyte
Secrete adipokines, a messanger that communicated with other body tissues (leptin)
- in obese individuals promote low grade inflammation and disease
Leptin
Acts on the hypothalamus to promote satiety
- When fat cells get larger, more leptin is released - this decreases appetite and promotes an energy deficit
Many obese individuals are leptin resistant
sick fat disease
adipokine secretion shifts to promote chronic low-grade inflammation
- type 2 diabetes
- cardiovascular disease
- certain cancers
- fatty liver
Fat mass disease
Added weight promotes biomechanics and structural challenges
- osteoporosis
- joint pain
- sleep apnea
- tissue friction
Define appetite
drive to consume food
Define hunger
Physiological need to consume food
Define satiety
sense of fullness that makes us stop eating and keeps us feeling full until the next meal
Obesogenic environment
The abundance of food and food cues in our environment promotes a constant stream of signals to promote high energy consumption
Individual psychology
Stress, metal health status and the way we think about ourselves and our bodies can affect both how much we eat and how much we exercise
Social psychology
out perched lack of time may compromise out ability to eat healthy and be active
physiology
we all handle energy differently - differences in microbiomes and appetite regulation can have significant effects on energy balance
Microbiome and energy balance
individuals with obesity are more likely to have more firmicutes in their colon ( bacteria are better at harvesting energy from food increasing energy intake)
What are the satiety signals
leptin (from adipose) and GLP-1(from small intestine)
What is the hunger signal
ghrelin (from stomach)
Body composition
= proportion of fat mass and lean body mass
Visceral fat
higher risk of disease
How can you measure body composition
- DEXA ( dual X-ray absorptiometry) scans the body in two planes –> body composition and bone density
- Air/water displacement: body weight/body volume = body density
- skin folds
- bioelectric impedance rate in which electrical current passes through the body ( fat has a greater resistance to current
- BMI - mass/height^2
- waist circumference: over 88cm for women and 102 cm for men is considered higher risk
willpower
our thinking brains ability ro override other signals
- should use skill power as well
Self-efficacy
belief in our ability to achieve a certain task
Mindfulness
being aware of and experiencing, the present moment with a judgement-free curious approach
Orlistat
- block the activity of lipase in the small intestine
- fat absorption, caloric intake decrease
Larglutide
- increases the activity of GLP-1
- promotes satiety
Naltrexone/Bupropion
Reduced food cravings by altering the reward circuit in the brain that drives food-seeking behaviour
roux-en-Y garlic bypass
a small upper part of the stomach is sectioned off from the rest of the stomach. It is then attached to the jejunum of the small intestine. Food bypasses most of the stomach as well as the duodenum and is not reversible
Sleeve gastrectomy
A banana-sized portion of the stomach is removed entirely. The overall size of the remaining stomach is significantly smaller. Not reversible
Gastric banding
An inflatable device is places around the upper portion of the stomach. Food must be party digested in this upper part before passing through the narrow opening in the stomach allowed by the band. Reversible
Risk factors for eating disorders
- genetics
- female
- socio-cultural ( pressure to be thin)
- personality ( perfectionism)
- history of sexual or physical abuse
Binge eating
loss of control of eating
- typically occurs in the absence of hunger and at a fast rate, associated with guilt or shame
Bulimia nervosa
involves binge eating and compensation
- vomiting, excessive exercise or laxatives
- Risk factors: preoccupation with food, distorted perception of body weight, depression
Binge eating disorder
Binge eating without compensation
- promotes obesity
- risk factors: frequent dieting, inability to interpret hunger/satiety signals
Anorexia nervosa
significant restriction in energy intake leading to an unhealthfully low body weight
- individuals often: have an intense fear of weight gain, feel disturbed by their weight or shape
Night eating syndrome
Abnormal increased food intake at night (>25% of caloric intake), lack of morning hunger, insomnia
Orthorexia nervosa
an obsession with eating healthy
signs:
- compulsively checking food labels
- cutting out foods, nutrients
- limiting food intake to narrow range of foods
Treatment of eating disorders
typically begins with diagnosis by health care providers
- main treatment strategies are psychologic
- education may also be prescribed
