Module 9 body composition, energy balance Flashcards
3 components of energy expenditure
Basal metabolism 50-65%
Physical activity 25-50%
Thermic effect of food 5-10%
How many calories in a pound of fat?
3500kcal (approximately)
Some factors affecting BMR
Age, height, growth, body composition, fever, stresses
What is EER?
Estimated energy requirements
BMI classes
underweight 18.5 healthy 18.5-24.9 overweight 25-29.9 obese 1 30-34.9 obese 2 35-39.9 obese 3 40+
Who is BMI not accurate for?
under 18, pregnant, lactating
Who is BMI less accurate for?
Leaner people, people over 65, certain races and ethnicities
How should BMI be used for the elderly?
healthy: 22-27
They need reserves during time of illness
Healthy body weight definition
Weight that does not increase risk of disease
2 types of fat (distribution)
Subcutaneous and visceral
Hunger vs appetite
Appetite is psychological (cues)
Hunger is physiological (hormones, nutrients, size and composition of meal)
What is leptin?
Satiety hormone that suppresses appetite
Gain in body fat stimulates leptin production
What is ghrelin?
Hunger hormone made by GI/stomach
High levels before meals
Increases gastric motility and gastric secretions
What makes foods more filling?
Protein (most)
Fat, fibre, high water, food puffed with air
Satiation vs Satiety
Satiation: determines amount consumed during a meal
Satiety: determines time between meals
Some health problems associated with being underweight
undernutrition, osteoporosis, infertility, impaired immunity
What happens to adipose cells during fat gain and loss?
Gain: increase in size and number
Loss: decrease in size
Enzyme that stimulates bodyfat production
Lipoprotein lipase (LPL)
What is set point theory?
The body will try to maintain a body fat range (homeostasis)
ie Fat loss: decreased energy expenditure, slowed metabolism
Summarize the findings of the Biggest Loser study
Even after contestants regained the weight they lost, their energy expenditure/metabolism remained slow (permanent adaptation)
Summarize weight stigma and bias
Overweight/obese people are seen as lazy.
This cause them cause them to feel bad, increase cortisol along with food intake resulting in further weight gain.
Summarize the new Obesity Canada guidelines 2020
Avoid weight stigma/bias, make it about health and wellbeing not just weight loss, realistic goals, sustainable changes
some benefits of weight loss
improve blood glucose, control type 2 diabetes, lower BP, better physical fitness, better blood lipids
How much weight loss is considered realistic?
5-10%
Benefits of moderate/slower weight loss
more likely to keep weight off, less metabolic adaptation, preserves lean body mass
What macro should be increased during weight loss?
protein
Types of bariatric surgery
Sleeve gastroectomy: remove 2/3 of stomach
Gastric bypass: reduce stomach size and bypass first part of SI
Duodenal switch: sleeve gastroectomy + bypass 80% of SI
All reduce tissues and the hormones they secrete
Possible complications of bariatric surgery
Nausea, vomiting, infection, lack of nutrients, dehydration, psychological problems
Obesity Canada guidelines for weight loss medicine
Over the counter: not recommended
Herbal/natural: not proven
Prescription: ie Orlistat (xenical) inhibits pancreatic lipase and blocks fat absorption by 30%
