Energy Balance Flashcards
What is body image ? What are some influences?
Body image is the perception of how we view our bodies and is often shaped by outside influences such as peers, family, clothing designers and the media.
Thin is portrayed by the media but what paradox is unfolding before us?
The world’s population is becoming heavier. In the last two decades there has been an increase in the number of people who are overweight or obese. In 1980 about 5% of men and 8% of women were considered obese. Today about 30% of the population in the United States is considered obese.
What is energy balance?
This is defined as energy intake being equal to energy expended. In other words, the number of calories ingested from food and beverages must be equal to the number of calories burned through basic body functions plus exercise.
Amount of energy that you take in is equal to the amount of energy that you use
A positive weight balance and its effect
More calories are consumed than expended and over time the excess consumption will lead to weight gain.
One pount of fat is equal to how many kilocalories ?
3500 kcal
Fat is stored in what type of cells ?
Adipose cells
What is hyperplasia?
This is one of the stages that occur in the devlopment of fat cells.
Hyperplasia occurs during periods of growth, such as adolescence of pregnancy, when we increase the number of fat cells in our body.
What is hypertrophy?
One of the stages that occur in the devlopment of fat cells-
this occurs in adulthood- while we may still continue to develop cells, it is more likely that the size of the cells will increase.
This is defined as energy intake being equal to energy expended. In other words, the number of calories ingested from food and beverages must be equal to the number of calories burned through basic body functions plus exercise.
Negative energy balance and when it would occur……
More calories are expended than are taken in.
This is not desirable and could occur when someone is fighting an illness or trauma that would negatively affect appetite and intake.
In other cases, an extremely high amount of energy is required for healing, such as someone who has suffered a major burn injury. However, for most of the population, being in negative energy balance is an intentional act. Calories are limited and or exercise is increased. The intended result is that over time this would lead to a weight loss.
Where does our sole source of energy intake come from ?
Food and beverages
Talk about the consumption of a Snickers bar and its efect on energy balance
Eating a readily available Snickers bar would provide you with 280 calories, coming from 14 grams of fat, 35 grams of carbohydrates and 4 grams of proteins.
This intake of 280 calories though means that, in order to prevent weight gain, 280 calories worth of energy must now be expended.
Energy expenditure is both ______________ and ____________________
intentional and naturally occuring
We can burn energy in the form of basal metabolism, physical activity, the thermic effect of food and thermogenesis.
What are the two major components of energy expenditure ?
Basal metabolic Rate (BMR)
and physical activty
What is BMR ?
Generally, what is the difference in BMR in males and females?
What accounts for differences in BMR?
The number of calories used by the body while in a fasting state.
In general, males require 1 kcal/kg/hour and females require 0.9 kcal/kg/hour to support the function of various body organs and to stay alive. The BMR varies per person based on a number of factors such as; gender, lean body mass, body size, temperature, age, nervous system activity, caffeine and smoking.
Pregnancy has an impact on a woman’s BMR. Women will have a higher BMR during their pregnancy. If someone is trying to lose weight and restricts their calorie intake too much, their BMR will decline. This is the body’s safety mechanism to prevent starvation.
BMR accounts for approximately ___________ of energy output
60-70%
How much does our BMR decline as we age?
1-2 % per decade
If no change in diet or activity level occurs from one decade to the next, a slow weight gain will be the result. This is why people in their 40’s and 50’s may indicate that they have gained weight and it is very difficult to lose.
Physical activty accounts for _____________ of our energy expenditure.
What factors can affect this?
15-40%
a number of factors, such as body size, fitness level and the actual activity, determine how many calories are expended. Low physical activity, being a couch potato, leads to weight gain.
Modern life is a battle against the whims and temptations of being couch potatoes.
True or false.
True.
In our society, modern conveniences do much of the work for us. As a result we live a much more sedentary lifestyle and must choose to be active.
What is the thermic effect of food and approximately what percentage of calories are expended from this?
This is the energy used for digestion and absorption of food, which accounts for approximately 10% of the calories expended.
Larger meals and meals higher in protein result in a higher TEF
What is thermogenesis?
The ability to regulate body temperature and activities such as fidgeting, maintaining body posture and shivering.
The amount of energy burned through thermogenesis is very small.
What is necessary to maintain a healthy weight?
Understanding how many calories your body requires on a daily basis
What is direct calorimetry and indirect calorimetry ?
Both are ways to measure the amount of energy your body needs…
Direct calorimetry measures the amount of heat that is given off by the body through the use of an insulated chamber but this method is expensive and complex.
Indirect calorimetry uses oxygen intake and carbon dioxide output and formulas to measure energy expended- this method is more accessible.
The formulas used are referred to as Estimated Energy Requirements.
These formulas are based on gender, age, height and weight and physical activity. The calories used for basal metabolism are part of the equation.
What are the Estimated Energy Expenditure formulas for males and females?
What does it tell us?
Below are the formulas used for males and females, as well as the physical activity estimates as published through the Food and Nutrition Board.
Males: EER = 662 - (9.53 x AGE) + PA x (15.91 x WT + 539.6 x HT)
Females: EER = 354 - (6.91 x AGE) + PA x (9.36 x WT + 726 x HT)
Where:
EER = Estimated Energy Expenditure
AGE = age in years
PA = Physical activity estimates in chart below
WT = weight in kilograms
HT = height in meters
1 kg = 2.2 lbsR
1 m = 39.37 inches
The formula tells us the estimated number of calories required per 24 hours to maintain a current weight.
Activity Level
Sedentary - No exercise
PA Men 1.00
PA Women 1.00
Low Activity - exercises the equivalent of walking 2 miles per day at 3-4 mph
PA Men 1.11
PA Women 1.12
Active - exercises the equivalent of walking 7 miles per day
PA Men 1.25
PA Women 1.27
Very Active - exercises the equivalent of walking 17 miles per day
PA Men 1.48
PA Women 1.45
The body mass index (BMI) is a tool used as an indicator of ……
a healthy weight
BMI= weight (in kilograms) divided by height squared (in meters)
BMI can be used as a measure of healthy weight, overweight or obesity in the general population. However, in certain populations such as children, teens, pregnant women, breast feeding women, short statute adults, very muscular individuals and the elderly the Adult BMI is not accurate. There are separate BMI tables for children and pregnant women.
