Lecture 8 - Energy Balance and Body Composition Flashcards
What is energy balance?
Energy in vs energy out
What does a shift in the balance cause?
Weight gain/loss
-rapid changes are not just fat changes, fat change is gradual
What does one pound of fat = in kcal?
3500kcals
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?
Thermogenesis
- basal metabolism 50-65% -life sustaining processes
- Physical activity 30-50%
- 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?
Influenced by: Gender Growth Age Physical activity Body composition
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?
Determine BMI
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
-kg/m^2
What are the 4 BMI categories?
Underweight (<18.5)
Healthy weight (18.5-24.9)
Overweight (25.0-29.9)
Obese (30+
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
Subcutaneous fat
What is waist circumference and indicator of?
Visceral fat
-different in each gender
What changes the idea of how a healthy person may seem?
Fat distribution
What is the bioelectrical impedance analysis?
Sends a very low electrical current through the body to measure the body composition
- most common
- handheld version available
When is the best time to do the bioelectrical impedance analysis?
No eating for 4 hours, no exercise for 12 hours, no alcohol for 48 hours
What would alter the results of the bioelectrical impedance analysis?
If you’re on your menstrual cycle (water is retained)
-3-4% human error
What is the e-ray absorptiometry?
Uses low dose x-ray which can identify and quantify home and soft tissue separately (differentiates between lean muscle and fat) to measure body composition
What is the bod pod?
Uses air displacement to easier body composition
-machine measures how much air is displaced when the person enters.
What is the downfall of the bod pod?
Accurate in caucasians but perhaps not in african american males
-uses computational data that already ahas error in it
What is the health risks associated with body weight and fat distribution?
Correlates with disease risk and life expectancy
What are the risks associated with being underweight?
Fighting against wasting diseases
Menstrual irregularities and infertility
Osteoporosis
What aren’t health risks?
BMI and waist circumference
What is the BMI to risk of mortality graph?
J shapped curve
- when you are at either low or high BMI, you have an increased chance of mortality (from different things depending on which side)
- lowest chance of mortality is when you are in the middle of the BMI range
What are the 3 types of adipose tissue accumulation?
Subcutaneous (SC)
Visceral Fat (VF)
Ectopic Fat
What is Subcutaneous fat?
Forms a layer under the skin
What is Visceral Fat?
Surrounds inner organs in the abdominal cavity
What is ectopic fat?
Fat accumulates inside organs and muscle, altering the metabolic activity
What kind of fat causes different metabolic responses?
Big vs small fat cells
-can be the same weight but the size can have different effects
How does ectopic fat lease to disease?
Metabolically stable/”healthy” obese
- absense of metabolic disorders in obese individuals
- 30% of obese patients are in metabolically healthy states
- low visceral adiposity (the have lots of subcutaneous space for fat)
- expandability of SC preserves their metabolism increase number of fat cells and volume)
What is fit fat vs sedentary slim?
compared to normal weight fit individuals, unfit individuals had twice the risk of mortality regardless of BMI
- overweight and obese fit individuals has similar mortality risks as normal weight fit individuals
- overweight fit people have lower risks than normal weight unfit people
What is an eating disorder?
A psychological condition that requires a diagnosis done by psychiatrists that are based on clinical data
What is the eating continuum?
Peoples attitudes towards eating and body image occur on a continuum
What are the categories of the eating continuum?
Food isn’t an issue
Concerned well
Food preoccupied/obsessed
Disruptive eating patterns/eating disorders
What is a eating disorder?
psychiatric condition involving extreme body dissatisfaction and long term eating patterns harming the body
What is disordered eating?
Variety of abnormal or atypical eating behaviours used to reduce or gain weight
What % of the population is affected by eating disorders?
2-5%
~3 million
What % of the eating disorder population are female?
90%
although the prevalence in men is rising
what % of young women ave substantially disordered eating attitudes and behaviour?
15-23%
What % suffer from binge eating disorder?
8% of women
30% of those seeking weightless suffer from this
-shame, guilt and restriction and the continuation of this cycle
-most often overlooked
What contributes to the development of an eating disorder?
Family environment
Personality traits (perfectionism, low self esteem, need for approval, all or nothing thinking)
Genetic and biological factors
What is the female athlete triad?
Characterized by
- Disordered eating - severe energy restrictions and multiple risk factors
- Amenorrhea - abnormal consequence of training due to low estrogen and body fat, and inadequate intake
- Osteoporosis - low intake and low estrogen
What are common triggers of eating disorders?
Major life transitions Family problems Social/romantic problems Failure at school, work Traumatic event Biological vulnerability to other psychiatric illnesses
What is Anorexia Nervosa (AN)?
Distorted body image, overestimating body fatness
-has to be diagnosed by a psychiatrist
What is the person doing to their body if they have AN?
Denying hunger Starving themselves Extensive knowledge of kcal in food Lots of exercise May abuse laxatives
How many people die from AN?
Has the highest mortality rate of any psych illness
-10% of individuals with AN die within 10 years of the onset of the disorder
What are the effects of malnutrition from AN?
Nutrient deficiencies Slower metabolism Irregula heartbeat Loss of brain tissue Impaired immune system Anemia Loss of digestive function Amenorreah
What is Bulimia Nervosa (BN)?
Binge and purge cycle
- Not physically apparent if you have BN
- weight fluctuations
What are the characteristics if you have BN?
Interference with work and activities Anxious in social settings Low self esteem/depression Impulsive Food preoccupation
What is the cycle of BN?
Negative self perception–> restrictive dieting–> binge eating–> Purging
Who is affected by BN?
Affects 1-4% of women
-male to female ratio is 1:6 to 1:10
What is the mortality rate for BN?
1% of BN patient will die from complications within 10 year of diagnosis
When is the rate for BN higher in men?
In sports where participants are encouraged to have low body weight
What is BED?
Binge eating disorder
-similar to BN but people do not purge, eat less during binge, less restraint during dieting
How is BED similar to BN?
Individuals feel out of control Depressed Disgusted Embarrassed Guilty Ditressed Inaccuate coping Severe negative body perception
What will males often describe destiny as?
Being healthy
-underlying issues are often similar to females
Why aren’t eating disorders as common in males?
Takes longer for diagnosis because we aren’t really looking for it
What are nutritional treatment goals for eating disorders?
Goals are
- non related to body weight
- Normalize metabolic rate
- Variety of foods consumed
- Acceptance of normal daily weight fluctuations
- Food consumption patterns normalized
- Hunger and fullness
What types of sentences should we not use when talking to someone with an eating disorder or in general?
You’re starting to lose/gain weight thats great
Im so glad you’re eating more
Wow you ate a lot today
Avoid comments about your own weight gain/loss or talking about needn’t to lose/gain weight
