Ch. 7: Energy Balance Flashcards
What is energy balance?
An equation of energy input and energy output, and how it contributes to your weight
When trying to maintain a healthy weight, your energy balance should be in a state of ____________, preventing weight loss or gain.
Equilibrium
Weight gain happens when you have a ___________ energy balance, while weight loss happens when you have a __________ energy balance.
Positive; negative
How is energy estimated in food?
Through the use of a bomb calorimeter; it measures the amount of calories from each macronutrient.
What is basal metabolism? (BMR)
The minimal amount of calories expended in a fasting state to keep a resting, awake body alive in a warm and quiet environment
How much of our total calorie needs go into basal metabolism?
60-70% of calories
What are some of the bigger factors that influence basal metabolism?
Lean body mass, body surface area, and basic biological facors (such as age and gender)
What is thermogenesis?
A metabolic process in which the body burns calories to produce heat
How much does physical activity account for total energy expenditure?
25-40% of calories
What is exercise-induced thermogenesis (EAT), and how does it differ from nonexercise activity thermogenesis (NEAT)?
EAT is the calorie expenditure for intentional physical activity, while NEAT is the same but for other activities, such as body posture or standing
How much does thermic effect of food account for total energy expenditure?
5-10% of calories
How does macronutrient content effect the thermic effect of food?
Some macronutrients have higher TEFs than others. Protein has a higher TEF because it takes more energy to digest and absorb.
What is thermic effect of food (TEF)?
The calorie expenditure of digesting and absorbing nutrients recently consumed.
What are the four variables that effect energy expenditure?
Basal metabolism, physical activity, processing of nutrients, and thermogenesis
Out of the four variables that effect energy expenditure, which one do we have the most control over?
Physical activity
What is adaptive thermogenesis?
The increase in nonvoluntary physical activity triggered by reflex responses, such as shivering
How is energy expenditure in humans measured?
Through direct or indirect calorimetry (usually indirect)
What is direct calorimetry?
A way of measuring energy expenditure in humans by putting them in a small room and measuring the body heat they release.
What is indirect calorimetry?
A way of measuring energy expenditure in humans by respiratory gas exchange, and measuring energy release from there.
What is body mass index (BMI)?
A widely used weight-for-height standard used to assess body composition and health
What potential problems are there with BMI?
It can’t accurately assess certain groups of people due to certain body composition statuses.
What percentage of body fat must you have to be considered obese?
Men at 25% and women at 32%
What are five methods that can be used to measure body fat?
Underwater weighing, air displacement, skinfold thickness, bioelectrical impedance, and dual energy xray absorptiometry (DEXA)
How does underwater weighing work?
The patient is weighed underwater; measurements are compared to conventional body weight
How does air displacement work?
Body volume is measured by the amount of space a person takes up in a measurement chamber.
How does skinfold thickness work?
Calipers are used to measure the fat layer under the skin. These values are put into a formula, and compared to standards seen in the human body
How does bioelectrical impedence work?
A painless, low-energy electrical current is sent through the body to estimate body fat. (Fat has greater electrical resistance than lean tissue)
How does DEXA work?
An expensive X-ray system is used to measure body fat accurately
What are the two types of body fat distribution?
Android (apple) obesity and gynecoid (pear) obesity
Which type of body fat distribution is more associated with chronic diseases, and why?
Android obesity because it involves fat being distributed moreso around internal organs
How does nature and nurture effect obesity?
Genes effect metabolic rate, fuel use and brain chemistry while nurture is where we get our learned eating habits
What is the chances of being obese based on parents’ weight?
If no parents are obese: 10%. If one parent is obese: 40%. If both parents are obese: 80%.
What are regular treatments of weight loss?
Control of energy intake, regular physical activity, and control of problem behaviors
How can a healthy weight be maintained?
Eating a low-fat, high-carb diet, eating breakfast, routine physical activity, and continuing to self-monitor
If you wanted to calculate weight loss for 3500 calories of fat, how would you do that?
1.) Multiply the pounds you want to lose and 3500 calories
2.) Divide that amount by the amount of DAYS you will be on the plan
From which part of the brain is satiety regulated?
The hypothalumus
How does the brain know when nutrients are present in the small intestine?
Nutrient receptors comunnicate with the brain through the nerves, and lets the brain know there are nutrients in the small intestine
How does the brain turn off the hunger drive and promot satiety?
Hormone secretions of cholecystokinin and peptides shuts off your drive for hunger, while the decrease of the hormone ghrelin promotes satiety
