Kin 110 Lecture 9

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Kin 110 Lecture 9

• Ch. 10 Weight Control

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Energy Balance and Imbalance

• Weight Control Overview
• Energy Balance
• What drives us to eat and participate in activity
• Indices for body composition assessment
• Fat distribution and health concerns
• healthful approaches to weight loss

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Energy Balance

• Fig 10-1
• Energy balance equilibrium
• Positive Energy Balance
• Negative Energy Balance
• Maintaining balance is important health goal for
  the prevention of many diseases
• Energy Intake (macromolecules)
• Convenience
• Energy density?
• energy content of a meal
• Calorimeter (fig 10.2)
• 1 kcal - energy to raise 1 kg of water 1 degree
  Celsius

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Energy Use

• Basal Metabolism (BMR)
• minimal energy needed to keep awake resting body
  alive
• 60 - 70 of total energy used by body
• 1 kcal/Kg/hour (males)
• varies 25-30 between people
• Liver, Muscle/Brain, kidneys, heart (in order of
  energy utilized at rest)
• BMR is influenced by
• lean body mass and surface area,
• Age - BMR declines 2 per decade after 30
• nervous and hormonal activity,
• nutritional state, pregnancy
• caffeine and tobacco use
• low energy intake - decreases BMR by 10-20

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Energy Use

• Physical Activity (variable)
• can increase energy expenditure 25-40 of total
• many choices available
• take stairs, walk to corner store, increase
  movement every day
• Thermic effect of food
• (5-10 ) of total intake
• Digestion and absorption, processes
• Slight variations with meal composition
• High protein and large meals require a little
  more energy to metabolize

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Energy Use

• Nonexercise Activity Thermogenesis
• (7)
• Overfeeding, fidgeting and shivering
• brown adipose tissue - infants
• Measurement of Energy Use
• Calorimeter
• direct / indirect
• Estimates by weight, degree of physical activity
  and age

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Estimating Energy Needs

• Sedentary - 20 kcal/Kg
• Light Activity - 30 kcal/Kg
• Heavy Activity - 45 kcal/Kg
• Estimates per day
• 1600 kcal/day
• sedentary women, older adults
• 2200 kcal/day
• active women, men
• 2800 kcal/day
• v. active women, active men,

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Food Intake

• Hunger - physiological drive to eat
• controlled by internal body mechanisms
• Appetite - psychological drive to eat, external
  stimulus
• Satiety - state in which there is no longer the
  desire to eat

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Estimating Healthy Weight

• Most are based on large population data,
• general guides not intended for individual
  application
• Family History of obesity related conditions is
  very important
• High BP, LDL, Blood Glucose,
• obesity, heart disease, cancer
• Important to make individual estimate of healthy
  weight
• what weight you maintained as an adult for one
  year without significant hunger
• Be realistic, healthy lifestyle is most important

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Healthy Weight

• Body Mass Index (BMI)
• Table 10-1
• body weight(kg) / height(m)2
• health risk with BMI over 25
• Significant health risk BMI gt30
• Severe health risk BMI gt 40
• over fat or overweight???
• Metropolitan Life Tables
• longevity not health, limited population inclusion

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Energy Imbalance

• Energy intake exceeds output
• can lead to obesity
• Obesity - excess body fat
• BMI over 30, weighing 20 more that healthy
  weight
• Health problems Table 10-2
• Over Fat
• males 25 , females 30-35
• BMI over 40 severe health risk
• Underwater weighing, Skin Folds, Bio-electrical
  impedance, dual X ray absorptiometry(DEXA)
• Fig 10-6 through 10-10

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Fat Distribution

• Fig 10-12
• Upper body obesity
• heart disease, high blood pressure, diabetes
• testosterone and alcohol
• lower body obesity requires about 20 lbs more
  for same health risk
• Waist girth
• Men gt 40 inches, women gt 35
• Waist to Hip Ratio
• gt1 men gt.8 women
• juvenile onset of obesity
• increased risk for obesity later in life
• 10 weight loss is all that is required for
  healthier weight

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Why ??

• Many factors both genetic (nature) and
  psychological (nurture) are influential
• Identical twins
• genes determine metabolic rates and brain
  chemistry
• Body Types
• ectomorph, mesomorph, endomorph
• differences in met. , surface area
• Thrifty metabolism
• Set Point Theory

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Environmental Influence

• Family eating patterns influences choices
• genetics ? Or habits?
• Little change in gene pool, but increase in
  obesity worldwide
• Table 10-3
• Overall, both nature and nurture influence the
  tendency toward obesity

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Treatment of Obesity

• Number two health risk in US after smoking
• chronic disease
• treatment requires long term lifestyle change
• No quick fix
• as with diabetes and high BP, need to have
  healthy active living with appropriate dietary
  modifications

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5 Principles of Treatment

• Goals of dieting misdirected
• be realistic, most under BMI of 25
• focus on healthy active lifestyle and maintenance
  of body weight
• Body defends itself against weight loss
• basal metabolism drops
• increased efficiency of fat storage
• Weight Cycling is Common
• 5 maintain loss, others gain more, increased
  health risk

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Principles

• Weight gain in adulthood is common
• Focus on changing Body Composition
• loss should be from adipose not lean tissue
• rapid loss is fluid and lean mass
• only highly motivated should attempt weight loss
• begin with maintenance, and awareness of eating
  habits and physical activity patterns

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Weight Loss Guidelines

• Fig10-13
• Control energy intake, increase expenditure,
  acknowledge that lifelong change is necessary
• Rate of Loss
• slow weight loss 1-2 Lb per week
• maintenance for a few months following 10
  reduction
• Flexibility
• participate in normal activities
• Individual taste and habits

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Weight loss Guidelines

• Intake
• meet nutritional needs
• minimum 1200-1500 kcal /day
• reduce hunger and fatigue
• choose common foods
• Behavior Modification
• lifetime focus to maintenance of healthy
  lifestyle
• changes are reasonable
• Overall Health
• Should consult physician if
• existing health problems, (over 40 men, 50 women)
  or plan to lose weight very quickly
• regular activity, rest, stress reduction
• address underlying psychological issues

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Controlling Intake

• Estimate requirements and reduce by 500 kcal /
  day
• One week 3500kcal 1 pound
• count fat (g) not entire diet
• focus on naturally low fat foods rather than fat
  reduced
• use exchange system (Appendix c)
• reduce fat but increase bulk
• complex carbohydrates, fiber
• stick to food guide, reduce high fat foods
• Table 10-4 - suggestions

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Physical Activity

• Regular activity has many benefits
• 200 kcal expenditure
• walking for 1 hour
• cycling for 30 min
• swimming for 20 min
• running for 15 min
• Lifestyle change - activity habits and daily
  routine
• quick walks, stairs, fidgeting
• Table 10-5 energy cost of various activities

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Behavior Modification

• Lifestyle changes
• Bad food intake and activity links
• Chain Breaking
• breaking link between behaviors that encourage
• overeating/inactivity
• Stimulus control
• altering environment
• Cognitive restructuring
• changing frame of mind regarding eating
• Create new rewards other than food

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Behavior Modification

• Contingency Management
• forming plans of action to respond to potential
  overeating situations and relapses
• Self Monitoring
• tracking of foods and conditions affecting
  choices
• Table 10-6
• lists many helpful behaviors
• Prevent lapse, relapse
• positive framing, social support

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Fad Diets

• Blood Type, personality, build, hair color
• Often use psychological appeal or pseudoscience
  biochemistry to convince people of their validity
• Simple solutions
• Cut back on animal fats, trans fats, sugar and
  junk food
• Choose healthy carbohydrates - high fiber
• Choose lean protein - fish and nuts
• Keep portions moderate
• Burger in 1957 - one ounce, now 6
• Popcorn in 1957 - 3 cups, now 16
• Exercise 3 times a week
• Be active

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High Fat Low Carb Diets?

• Atkins latest claim - years of promoting low
  fat diets and the population still gaining
  weight
• Fact - Americans are eating as much fat now as
  before.
• The percent fat may have gone down slightly, but
  the intake of sugar has gone up dramatically
  along with total calories
• Atkins claims - we gain weight from carbohydrates
  intake causing hunger
• No evidence - sugar? Definitely not whole foods
• Atkins claims - carb intake causes insulin
  resistance
• While these numbers are increasing - metabolic
  syndrome
• No evidence to link to carbohydrates
• Study showed no difference in insulin levels
  between high and low carb diets

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Atkins continued

• Proper high carb diet can help people lose weight
  and reduce risk of heart disease
• Atkins claim - there is an exercise boom in the
  US, but the population is still gaining weight,
  must not work
• Exercise boom is limited to a small percentage of
  the population, on average people are becoming
  more sedentary
• Atkins claim- his diet works, lots of anecdotal
  evidence
• works in short term, but no better than any diet
  that restricts calorie intake
• Survey of successful weight loss gt One year,
  extremely small percentage used low carb diet
  despite millions of books being sold
• Given zero out of five stars for health

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Learning Objectives

• Describe use of energy by the body and what
  constitutes energy balance
• Describe how to diagnose overweight and obesity
• Outline health risks with overweight and obesity
• Discuss factors affecting energy balance - nature
  vs nurture
• Describe how components of a weight loss plan fit
  together
• Outline benefits and hazards of various weight
  loss methods
• Evaluate fad weight reduction diets and determine
  which are unsafe, doomed to fail, or both