Chapter 6: Overweight & Obesity Exam 2 Flashcards
When we take in more calories (energy) than we expend..
The excess gets stored as body fat
What cycle are our bodies designed to function on?
Feast or Famine Cycle
Only __ % of people are successful at losing weight and keeping it off
5
What should be focused on more health or looks?
Health
Type II Diabetes Risks
Excess body fat promotes insulin resistance and fat storage
Cancer Risks
-Excess body fat increases estrogen levels promoting estrogen dependent cancers (breast cancer)
-Promotes systemic inflammation increasing cancer risks
Respiratory Problems Risks
-Excess body fat (especially belly fat) crowds internal organs and disrupts functioning of the diaphragm
-Results in short, shallow breaths and difficulty breathing
-Chronic inflammation constricts airways and promotes asthma
-Excess weight around neck promotes sleep apnea
Digestive Problems Risks
-Increased risk of gastric reflux disease (GERD) and esophageal cancer
-Increased risk of fatty liver disease
Impaired Temperature Regulation Risks
-Excess fat insulates and impedes heat loss
-Promotes hyperthermia during exercise increasing risk of heat illness
Heart Disease, Stroke, & Hypertension Risks
-More fat cells = greater oxygen & nutrient demand
-Every extra pound of body fat has 5 miles of blood vessels that need to be serviced
-To meet this demand heart rate speeds up & blood volume rises
-Excess pressure damages artery walls increasing risk of plaque formation & aneurysms
-Excess weight makes heart work harder
Fat
Living tissue that requires an oxygen and nutrient supply
Elevated Blood Fats Risks
-When fat cells become too big they spill their contents out into the bloodstream
-Results in high LDL & triglyceride levels
Osteoarthritis Risks
-Excess weight causes extra wear & tear of cartilage in knees, hips, lower back
-Risk increases 9% to 13% for every two-pound increase in weight
-Creates postural & balance problems (lordosis) as center of gravity shifts
-Thickening of synovial fluid & decrease in synovial fluid production due to inactivity
White Fat Cells
-Metabolically inactive fat cells involved in triglyceride storage
-Comprise 98%-99% of total fat cells
Brown Fat Cells
-Metabolically active fat cells involved in heat production & regulation
-Comprise only 1%-2% of total fat cells but account for 20%-50% of heat production
-Most located between shoulder blades
Exercising in the cold for 2 hours daily at 66 degrees can increase the number of ____ fat cells
Brown
What type of fat cell is shivering imitated by?
Brown Fat Cells
Hypertrophy
-Growth in the size of the fat cell when calorie intake is greater than expenditure
-Fat cells will continue to grow until they reach a size where they become mechanically stressed
-Fat becomes metabolically active & starts spilling out into the bloodstream & triggers system wide inflammation
-Exercise & diet shrink fat cells by using fat instead of storing it
Hyperplasia
-Increase in # of fat cells
-Genetically determined
SCAT Fat (subcutaneous adipose tissue)
Found just under skin and around hips & buttocks
VAT Fat (visceral adipose tissue)
-Deep abdominal fat found around internal organs
-Larger more metabolically active cells that secrete fatty acids & inflammatory molecules (cytokines) into bloodstream
-Promotes high blood lipids, systemic inflammation & changes in organs, arteries, & cells
-Fat cells also have a direct circulatory route to the liver (portal vein)
-Leads to increased risk of heart disease, stroke, diabetes, cancer, & liver disease
Liver Fat (non-alcoholic fatty liver disease)
-Excess visceral fat overwhelms the liver resulting in fat accumulation inside the liver & fat spilling out into the bloodstream
-Causes liver inflammation that can progress to cirrhosis & liver failure -Promotes high blood lipids, heart disease, diabetes, high blood pressure, kidney disease, & metabolic dysfunction
Muscle Fat (sarcopenic obesity)
-Accumulation of fat within & between muscle cells
-Results in loss of muscle tissue (cachexia) due to cytokine induced inflammation
Sarcopenic Obesity
Invasion & accumulation of fat within & between muscle cells due to cytokine induced inflammation
Cachexia
-Loss of muscle tissue due to toxic effects of cytokine induced inflammation
-Begins in mid-thirties
-Average muscle loss of 30% to 50% by the time people reach their 80’s
-Explains why body mass index (BMI) and/or scale weight can be in or below normal range when body fat levels are high
Consuming ____ calories than we expend is the major contributor to obesity
More
Weight Maintained Isocaloric Balance
Energy In = Energy Out
Weight Loss Negative Caloric Balance
Energy In < Energy Out
Weight Gain Positive Caloric Balance
Energy In > Energy Out
Tips on Calculating Calories In
-Keep a 3-7 day food diary
-Read nutrition facts labels
-Estimate average daily caloric intake
-Pay attention to serving sizes
What Makes Up Calories Out?
-Basal Metabolic Rate (BMR) 60%-70%
-Activity 20%-30%
-Thermic Effect of Food 10%
Basal Metabolic Rate
-Slows 3% per year up to the age of 20
-Remains stable between the ages of 20 and 60
-Slows at only 0.7% per year after 60
Calculating Daily Calories Out
-No Exercise: BW x 10 cal/lb
-1-2 Exercise Sessions Weekly: BW x 12 cal/lb
-3-4 Exercise Sessions Weekly: BW x 14 cal/lb
-5+ Exercise Sessions Weekly: BW x 16 cal/lb
How to Lose Weight
-Create difference between caloric intake (food diary) & caloric expenditure (calculation)
-Goals, realistic, comfortable
-Need to re-calculate caloric expenditure with new body weight weekly or weight loss will slow down
How many calories are in one pound of body fat?
Roughly 3,500 calories
To lose one pound of fat we need to increase physical activity and/or reduce caloric intake enough to create a ___ calorie deficit per day for seven days
-500
-2 pounds 1,000 calories (daily)
What is healthy & sustainable weight loss?
About 1-2 lbs per week
What can losing more than two pounds per week (1,000 calories per day) result in?
-Decrease the metabolic rate to conserve energy (adaptive thermogenesis)
-Metabolize muscle tissue resulting in water loss
Does energy demand increase or decrease with weight loss?
Decrease
Body Fat Mobilizers
-Glucagon
-Epinephrine (adrenaline)
-Norepinephrine
-Growth Hormone
-Aerobic exercise > 20 continuous mins increases these levels
-Creates a hormonal & enzymatic fat burning environment
Body Fat Inhibitors
-Insulin
-Lactic Acid
-Exercise automatically decreases insulin levels
-Lactic acid generated through intense exercise inhibits fat mobilization
-To maximize fat burning
Insulin
Stores body fat & inhibits fat mobilization & growth hormone release
How can you keep insulin levels low?
Avoiding excess dietary carbohydrates especially immediately before & during exercise
How to keep lactic acid levels low?
Limiting high intensity/short duration activities
Low to moderate intensity/long duration aerobic exercise burns ____
Body Fat
___ is the primary fuel at intensities <40% HRR and duration of >20 continuous minutes
Fat
Crossover Point
20 min of continuous exercise
High intensity/short duration anaerobic exercise burns ______
Carbohydrates & increases lactic acid
______ is the primary fuel at intensities >80% HRR and duration <20 minutes
Carbohydrate
Aerobic Exercise Prescription for Fat Loss
- Frequency: 5 or more days per week
-Intensity: 40-59% of HRR, RPE of 4-6/Talk Test, can progress to 60% or higher but not exceed 80% HRR, 60-70% of HRR ideal for fat burning range
-Time: start goal of 30 min per day, progress to 50-60min per day, warm-up & cool-down 5-10min
-Type; Prolonged rhythmic, large muscle group exercise
Does resistance training result in significant weight loss?
No
One pound of muscle burns approximately ___ calories day as compared to one pound of fat at ___ calories per day
6 & 2
What can resistance training improve?
-Muscle Strength
-Muscle Endurance
-Functional Capacity
-Decrease intramuscular fat
Resistance Training Prescription When Goal is Fat Loss
-Frequency: 2-3days w/ minimum 48 hrs recovery per muscle group
-Intensity: 60-70% of 1RM to enhance strength & muscle mass
-Time: 2-4sets of 8-10 exercises focused on major muscle groups, progress to multiple set routines, 1-2min rest between sets
-Type: Anything that provides resistance
Resistance Training Prescription for Intramuscular Fat Loss
-Frequency: 3 days per week w/ minimum 48hr recovery per muscle group
-Intensity: Less than or 40% of 1RM or load that can be lifted 30-50reps to near fatigue, RPE 12-13
-Time: 2 sets of 8-12 exercises on major muscle groups, perform circuit format minimizing rest time between exercises & sets
-Type: Free weights and/or selectorized machines
Surgical Intervention
-Bariatric Surgery
-Different methods decrease size of stomach
-Reduces amount of food and calories consumed
-Reduces amount of grehlin released into blood suppressing appetite & inhibiting fat storage
Heredity Factor in Not Losing Weight
-Body type, genes and metabolism are inherited
-Family history increases obesity risk 25% - 30%
-80% of obese children have obese parents
Overfeeding Factor in Not Losing Weight
During critical growth periods (between 3rd and 9th month of pregnancy, first year of life and puberty ages 9-13) overfeeding can increase the total number of fat cells
Set Point Theory Factor in Not Losing Weight
-Genetically predetermined weight and/or body fat range
-Metabolism either increases or decreases to stay within that range
Hypothyroid Factor in Not Losing Weight
-Thyroid gland releases thyroxine that controls metabolic rate
-Low levels of thyroxine decrease metabolic rate lowering caloric expenditure
Diabetes Factor in Not Losing Weight
Insulin resistance increases fat storage especially abdominal fat
Faulty Brain Signals Factor in Not Losing Weight
-Either increases or decreases metabolic rate based on how much food is consumed
Hypothalamus
Command center in the brain that regulates energy intake & expenditure
Two Hormones that Signal Hypothalamus
Leptin & Grehlin
Leptin
Signals the hypothalamus that you’re full & appetite decreases
Grehlin
Signals the hypothalamus that you’re hungry & appetite increases
Brown Fat Cells Factor in Not Losing Weight
-Some people may genetically have more or less of the standard 1%-2% -Exercise in cold environments may increase the number of cells
Psychological Factors in Not Losing Weight
-Food provides comfort and meets emotional needs
-Eating disorders /triggers/stress
-Eating by the clock
-Social rituals
