Flashcards in Lecture 8 - Energy Balance and Body Composition Deck (75)
What is energy balance?
Energy in vs energy out
What does a shift in the balance cause?
-rapid changes are not just fat changes, fat change is gradual
What does one pound of fat = in kcal?
Where is excess energy stored?
As fat and used in between meals
Why does energy in not equal energy out?
Because genetics, adipose tissue, medications, hedonic input etc all play into account as to how you lose/gain weight
What is a bomb calorimeter?
foods are placed into the calorimeter and burned. As they are burned, they release heat, CO2 and H2O
How do you calculate how many calories are from the macronutrients?
take energy per g (4 or 9) and multiply it by how many grams you are eating
How do you find the % calories you are eating?
Take how many grams of each macronutrient and divide by the total number of kcal consumed will give you %
What is energy in dependent on?
Appetite - psychological and cues
Hunger - psychological response, hypothalamus, press or absence of nutrients in blood, size and composition of meal
Satiation - stop eating, feeling of fullness
Satiety - do not start eating again, overriding factors
What is the appetite (psychological response) based on?
Our survival mechanism, we are always looking for food and are always thinking when do i get to eat again and how much
What is hunger (physiological response) based on?
Really hard to ignore the body and what it needs. The body will response with low blood sugar and irritability if you ignore it
What are the 3 things energy out is based on?
1. basal metabolism 50-65% -life sustaining processes
2. Physical activity 30-50%
3. Food consumption 10% - thermic effect of food (TEF)
What is NEAT?
Body adjusts your weight to what your body is doing
-not a lot of activity, it will burn calories accordingly
What are we unable to easily change body weight?
Hormones regulate body metabolism and the body will slowly regulate to where it wants to be, even if you love/gain weight
What is biggest loser study?
Individuals all lost an extreme amount of weight very quickly, so the metabolism quicker in to burn more energy, but it was doing this too quickly and started to slow down because your body wants to protect its resources incase of a famine. After a while the people gained back ~100 pounds. but their metabolism didn't increase, it stayed at this lower rate.
-survival mechanism was engaged so the people were fighting to lose weight against the body survival mechanism
What is EER?
Estimated energy reqiurements
What is EER influenced by?
What is the definition of a healthy body weight?
Appropriate for age and physical development
-achieved and sustained without severely curtailing food intake or constantly dieting
-acceptable to you
What does a healthy body weight promote?
Good eating habits and allows for participation unregulated physical activity
What us the healthy body weight based on?
Genetic background and family history of body shape and weight
What is not a good measure if someone is healthy?
Weight and BMI
How would you determine if the persons body weight is healthful?
Measuring body composition
Assessing the pattern of fat distribution
What is BMI?
Expresses the ration of a persons weight to the square of their hight
What are the 4 BMI categories?
Healthy weight (18.5-24.9)
Based on BMI alone, is the % of obese people increasing?
No, % stays around the same. More of the people converting from healthy body weight to overweight
What are the limitations of BMI?
Doesnt tell us
-where fat is stored
-Difference between bone muscle and fat
-physical and metabolic differences
Why does body fat distribution matter?
Important information for disease risk
-ideal amount of fat depends on gender
What are the 2 types of fat distribution?
Visceral fat - Central obesity
What is waist circumference and indicator of?
-different in each gender