Module 3 (bio 121)
what are the three components to weight loss and weight maintenance that must be implemented in order to be successful?
(1) control of calories -portions vs. servings (2) physical activity -60-90 min exercise (3) behavior modification -intervention strategies
drastic weight loss measures include
(1) medications (2) extremely low-calorie diets (3) surgery
times when an individual may be in negative energy balance
- UNINTENTIONAL during an illness or trauma as they would negatively affect appetite and intake - someone who has suffered a major burn injury (an extremely high amount of energy is required for healing) - INTENTIONAL calories are limited and/or exercise is increased with the goal of weight loss
intervention strategies
-->Chain breaking -->Stimulus Control -->Cognitive restructuring -->Contingency management -->Self-Monitoring
methods that can be used to determine a person's body fat content (4)
-Underwater weighing -Bioelectrical impedance -Dual Energy X-ray Absorptiometry (DEXA) -Anthropometrics
Bioelectrical impedance
-based on the principle that water conducts electricity and fat resists electricity. Process: an instrument with electrodes is connected to the body and a painless low energy electric current is sent through the body. Why works: -muscle is primarily composed of water -fat resists electricity, higher levels of resistance indicate a higher percentage of body fat.
Resistance exercises health benefits include
-builds muscle -builds lean body mass -resistance and stretching exercises tone the body -bone mass is preserved which helps fight osteoporosis later in life.
How do people think of a diet negatively?
-thoughts of starvation -limiting food -denying oneself of enjoyable foods -quick fix
Physical Activity (PA) Estimates
1.2 = little to no exercise 1.375 = light exercise 1-3 days per week 1.55 = moderate exercise 3-5 days per week 1.725 = hard exercise 6-7 days per week 1.9 = hard daily exercise/job
The daily standards of calorie control for females and males is no less than ______ and ______ calories, respectively Minimal # calories should consume
1200 1500
females should have between _________ to ________ body fat
21% to 35%
In order to prevent weight gain, it would be necessary to expend _______ calories worth of energy, a process that can happen both naturally and intentionally
282
In males, a waist circumference greater than _____ inches and in females greater than ______ inches results in a diagnosis of obesity
40 35
by consuming an extra ________ calories a day over what is expended, you could gain _________ pound in a week
500 one
Current recommendations are for _____-____ minutes of activity per day, as well as _______ steps
60-90 10,000
Female BMR calculation
655 + (4.35 x weight in pounds) + (4.7 x height in inches) - (4.7 x age)
Male BMR calculation
66 + (6.23 x weight in pounds) + (12.7 x height in inches) - (6.8 x age)
genes account for _____% of an individual's body weight, we thus ______ specific body types.
70% inherit
Males should have between ________ to _______ % body fat
8% to 24%
caliper
A measuring instrument having two adjustable jaws typically used to measure diameter or thickness. one important type of anthropometric measure
Body Mass Index (BMI) ranges
BMI < 18.5 (underweight) BMI 19-24.9 (healthy weight) BMI 25- 29.9 (overweight) BMI 30 or > (obese) BMI 40 or > (morbidly obese)
calculate the energy requirements (EER) for a female who is 30 years old, 5 feet 5 inches, 140 pounds with light activity.
BMR = 655 + (4.35 x 140) + (4.7 x 65) - (4.7 x 30) BMR = 655 + (609) + (305.5) - (141) BMR = 1,569.5 - 141 = 1,428.5 BMR x PA estimates = 1,428.5 x 1.375 = 1,964 calories daily
what is the body's safety mechanism to prevent starvation?
BMR will decline
components of energy expenditure
Basal metabolic rate BMR Thermic effect of food Thermogenesis Physical activity
-is an improved measure of body fat relative to one's height and weight. -replacement to the height-to-weight tables -can be used to categorize an individual as being underweight, at a healthy weight, overweight, or obese
Body Mass Index (BMI)
1. chain breaking
Breaking the tie that connects two or more behaviors that encourage overeating. i.e instead of munching on snacks while watching TV, limit yourself to eating only in the kitchen while seated at the table.
What are ways to control amount of calories consumed?
Caloric intake monitored through label reading keeping food records and measuring portion sizes knowing the appropriate portion to eat limit high-fat foods
3. Cognitive Restructuring
Changing your frame of mind regarding food. i.e Rather than turning to food when you are stressed, you decide to exercise instead. After the exercise, if you still want to eat something, allow yourself a small portion of that food.
Healthy Tip: for controlling consumption of calories
Drinks can also contain a large number of calories. However do not get the same feeling of satiety you would with solid foods. Limit drinks loaded with sugar and choose no-calorie or low-sugar beverages to help with weight control.
why do females require higher levels of fat?
Females require higher levels of fat for reproduction
2. stimulus control
Finding ways to avoid temptation when we are hungry or bored. i.e not buying convenience foods you are fond of or limiting yourself to one small piece of chocolate daily.
which method of determining if someone is a healthy weight was used for the general population but did not take into account individual differences?
Height-weight tables
Excess calorie consumption eventually leads to an increase in body fat. Fat is stored in adipose cells, which are often categorized by two distinct stages:
Hyperplasia Hypertrophy
Healthy Tip: on adding exercise into daily routine
In order to ensure success, choose enjoyable activities and vary them to prevent boredom. Always be looking for ways to add physical activity to your day such as walking to a colleague's office to discuss business rather than sending an email, using the restroom one floor below you and taking the stairs instead of the elevator to get there, or parking at a spot away from the entrance to the mall to add extra steps to your trip. With a little planning and imagination, implementing daily exercise opportunities can be very easy
Who are individuals that may require drastic weight loss measures as controlling calories, physical exercise, and behavior modification are not enough to achieve a healthy weight?
Individuals with a BMI of >30, or > 27 with co-morbid health risks (referred to as morbid obesity)
5. Self-monitoring
Keep a diary for several days, recording what you eat, when you eat it, how you felt and where you were when you ate. reveals patterns that may be negatively affecting your weight loss efforts. Behavior modification is extremely important in understanding our eating habits and helping us to make changes to meet our weight loss goals.
Gynoid obesity (lower body)
LOCATION: fat being stored below the waistline BODY SHAPE: yielding the commonly referred to "pear" body shape; small waist with much of the fat deposited in the hips and thighs. PRO: located away from internal organs and heart so does not cause serious health issues CON: harder to get rid of COMMON IN: the female form
Android obesity (upper body)
LOCATION: fat being stored in the abdominal area BODY SHAPE: yielding the "apple" body shape "more weight above waist" COMMON IN: males PRO: easier to get rid of CON: located close to internal organs and heart so causes serious health issues DISEASES LINKED TO: high blood testosterone levels and an increased risk of diabetes and hypertension. BEHAVIORS CONTRIBUTE: Alcohol consumption smoking diet with a high glycemic load
which types of meals result in higher thermic effect of food
Larger meals and meals higher in protein
What is the hormone that studies are being conducted to determine its exact role in weight regulation?
Leptin
appetite reduction drugs
Meridia medication used to decreases hunger sensations. moderate reduction in appetite is helpful to people who eat a fairly healthy diet but consume excess quantities
obesity affects some groups more than others
Non-Hispanic Black adults (49.6%) = highest age-adjusted prevalence of obesity Hispanic adults (44.8%) non-Hispanic White adults (42.2%) non-Hispanic Asian adults (17.4%)
Absorptiometry/DEXA
PRO: most accurate measure of body fat composition as well as bone mass. Process: An instrument that emits small doses of radiation determines the amount of fat, lean tissue, and bone in an individual. CON: it is very expensive and rarely used.
underwater weighing
PRO: very accurate process Process: individual is weighed on a scale and then again while under water. difference between the two measurements (normal vs. underwater) used to estimate total body volume. From this the percentage of lean muscle and body fat can be calculated.
4. Contingency management
Preparing for situations that might trigger over eating i.e a party or donuts at the office. If you have a board meeting to attend and you know the boss will be bringing in donuts, offer to bake a low-fat coffee cake as an alternative for those trying to watch their weight.
what factors play key roles in our body composition?
Sex, age, race, and ethnicity
________ ___________ is complementary to behavior modification and perhaps equally important for weight loss and maintenance.
Social support (family, friends, social programs, and/or professional help)
why are behavior modification strategies so important?
The majority of successful losers end up regaining the weight they lost within five years provide strategies that can be followed long term regardless of what stage of life you are in
Can being physically active do more for you than just burn calories?
Yes. -decrease your stress level -improve your mood -increase productivity -maintain bone health -increase lean body mass leading to more efficient use of calories even at rest
energy balance
a state when one's energy intake is equivalent to the amount of energy expended. number of calories ingested from food and beverages must be equal to the number of calories burned through basic body functions + exercise
In males, excess fat stored within _____________ tissues interferes with the _________ ability to use insulin (resistance), increased risk hypertension & cardiovascular disease, and increased risk type 2 diabetes.
abdominal livers
forms of obesity
android obesity gynoid obesity
why are people in their 40s and 50s will often complain about gained weight and how it has become difficult to lose?
as we age our BMR declines by 1-2% per decade. if one fails to make changes in diet or activity levels from one decade to the next, a slow weight gain will be the result
set point theory
belief that brain mechanisms regulate body weight around a genetically predetermined 'set point' states that body will resist change beyond this set point. This set weight is a weight that was not difficult to maintain on your part. related to various hormones and enzymes
Fat cell development
biological factor once a fat cell is formed, it is always present. our bodies are predisposed to want to fill the fat cells. is possible to shrink the size of fat cells, cannot get rid of fat cells through dieting.
How is BMI calculated?
calculated by dividing one's weight (in kilograms) by the square of one's height (in meters). BMI = weight (kg) / height2 (meters)
what diseases have an increased risk in women after menopause?
cardiovascular disease hypertension diabetes
(1) medications
classified into one of three classes: -amphetamines -appetite reduction drugs -fat absorption inhibitors
Waist-to-hip ratio (WHR)
first measure around the waist (at the level of the belly button) while relaxed. Next, measure the hips around the largest part of the buttocks. Finally, divide the waist measurement by the hip measurement. The desired ratio in males is <0.9 and in females < 0.8
BMR varies per person based on a number of factors such as
gender lean body mass body size temperature age nervous system activity levels of caffeine intake tobacco use (smoker higher BMR)
formulas used to calculate the amount of energy required daily per individual are based on what?
gender, age, height and weight, and physical activity
Obesity-related conditions include
heart disease, stroke, type 2 diabetes and certain types of cancer
In females, the fat around the _______ & _________ is less likely to cause health issues, but it is very difficult to shed. After menopause, the shift in ____________ results in an increased risk of _________ body obesity
hips and thighs hormones upper
Social programs may include
hospitals community colleges Strength training programs restaurants as they can be good resources for healthy cooking classes
What health effects can the over expression of substances that fat cells produce lead to? which causes an increased risk for hypertension, cardiovascular disease, and type 2 diabetes?
increased blood clotting blood vessel constriction inflammation
serving size
is a specific measurement of food
Hyperplasia
is an increase in the number of fat cells often occurring during periods of growth, such as adolescence or pregnancy.
hypertrophy
is an increase in the size of fat cells, most often seen in periods of low growth and maintenance, such as throughout adulthood.
thermogenesis
is the ability to regulate body temperature and activities such as fidgeting, maintaining body posture, and shivering.
While the amount of body fat we have is important, so is the ___________. Fat can be stored in the _______ body or the _______ body. Where it is located can have an impact on your _________.
location upper lower health
what is the rate for both males and females required to support the functions of various organs and to stay alive?
males require 1 kcal/kg/hour females require 0.9 kcal/kg/hour
direct calorimetry
measures : the amount of heat given off by the body. An insulated chamber surrounded by a thin layer of water is used to measure the amount of heat emitted by the subject in the chamber
thrifty metabolism gene
more fat storage to protect against famine fewer calories than normal are used to maintain body function. prone to weight gain as their unusually low basal metabolic rate results in fewer calories being burned, which encourages the storage of fat.
how do you determine individual energy requirements (EER) or number of calories required to expend daily in order to maintain their current weight?
multiply the BMR x PA estimates (relative to the appropriate activity level).
ways in which energy can be expended
naturally: -via basal metabolism, -the thermic effect of food, and -thermogenesis intentionally: -physical activity
what determines our body fat composition?
nature nurture thrifty metabolism set point
basal metabolic rate (BMR)
number of calories used by the body while in a fasting state and accounts for approximately 60-70% of energy expenditure
negative energy balance
occurs: if fewer calories are consumed than calories expended.
positive energy balance
occurs: if more calories (energy) are consumed than expended.
Height-weight tables
often published by insurance companies, were used in an attempt to link longevity to a person's weight as based on their height.
examples of certain periods when we need to consume more calories than we expend
periods of growth, such as pregnancy or periods of childhood, and adolescence when growth spurts occur
what accounts for 15-40% of our energy expenditure?
physical activity
Professional help would include
physicians, exercise physiologists, and registered dietitians.
what populations is the BMI not as accurate?
populations include: children teens pregnant or breast-feeding moms short statute adults very muscular individuals elderly
Label Reading
process of comparing labels on similar products in terms of serving size, number of calories per serving, and the amount of fat per serving
(1) control of calories
regulating the number of calories you consume daily to be successful: -change the way you think about weight loss -think of calorie control in terms of lifestyle change -can be followed for the remainder of one's life -goal is to lose 1-2 pounds per week
(2) physical activity
second key to weight loss and maintenance
what are environmental factors that affect our weight?
sedentary lifestyle socioeconomic status friends and family cultural and ethnic influences availability of high fat foods excessive TV viewing lack of sleep emotional eating stress fast food smoking cessation
The amount of energy burned through thermogenesis is very ____________.
small
Amphetamines
stimulate the central nervous system and burn calories. only used short term as abuse or even a dependency can be developed
porpotion
the amount of food you choose to eat
How are low-fat and fat-free products deceiving?
the calorie difference between low-fat and its regular counterpart can be marginal make up for the lack of fat, extra sugar or salt may be added to improve the taste of the product
Thermic Effect of Food (TEF)
the energy used for digestion and absorption of food and accounts for approximately 10% of the calories expended.
Anthropometrics
the science of measuring the proportions and size of the body (Most commonly used) PRO: offers a more practical method to determine body fat composition. can be done quickly and fairly accurately Process: Skin fold measures using a caliper measuring the fat layer just under the skin at several locations, the percent body fat can be calculated. CON: person doing the measurements must be trained properly
(3) behavior modification
third key to weight loss and maintenance describes; how certain factors (or behaviors) can prevent us from reaching our weight loss goals
indirect calorimetry
uses oxygen intake and carbon dioxide output, along with scientific formulas, to measure energy expended. It is convenient, fairly cheap, easy, and very portable.
In addition to the body shape, ________ _________________ can also be used as an indicator of obesity
waist circumference
final method of using anthropometrics to determine if someone is overweight is the _______-____-_____ ratio
waist-to-hip
do nature and nurture play a part in determining our body shape?
yes
Is there is a difference between portion size and serving size?
yes. A serving is a specific measurement of food A portion size is the amount of food you choose to eat
