Energy Balance and Body Composition

1
Energy Balance and Body Composition

• Chapter 8

2
ENERGY
IN
OUT
3
Energy Balance

• Excess energy is stored as fat
• Stored fat used for energy between meals
• Energy balance energy in energy out
• A shift in balance causes weight changes
• fat changes
• body composition changes- LBM, H2O
• 1 pound of fat 3500 kcalories
• Health fat storage 50,000 - 200,000 kcal

4
Energy In Food Composition

• Direct measure of foods energy value
• Bomb calorimeter
• Indirect measure of energy released
• Oxygen consumed
• Heat released
• kCalorie calculations from grams prot, CHO, fat,
  EtOH

5
Insulated container keeps heat from escaping

Thermometer measures temperature changes
Motorized stirrer
Reaction chamber (bomb)
Food is burned
Heating element
Water in which temperature increase from burning
food is measured
6
Energy In Kcal Intake

• Hunger pain that causes food-seeking
• Appetite integrated response to nerve signals
  and chemical messengers
• Hypothalamus
• GI hormones, neuropeptide Y
• Satiation fullness, stops eating
• Satiety fullness that lasts til next meal
• Influences that override physiological signals
• positive (parties) and negative (grief)

7

1
Physiological influences Empty stomach
Gastric contractions Absence of nutrients in
small intestine GI hormones Endorphins (the
brains pleasure chemicals) are triggered by the
smell, sight, or taste of foods, enhancing the
desire for them
2
Sensory influences Thought, sight, smell,
sound, taste of food
5
Postabsorptive influences (after nutrients
enter the blood) Nutrients in the blood signal
the brain (via nerves and hormones) about their
availability, use, and storage As nutrients
dwindle satiety diminishes. Hunger develops
1
Hunger
Seek food and start meal
2
Satiety Several hours later
5
Keep eating
3
Satiation End meal
4
3
Cognitive influences Presence of others,
social stimulation Perception of hunger,
awareness of fullness Favorite foods, foods
with special meanings Time of day Abundance
of available food
4
Postingestive influences (after food enters
the digestive tract) Food in stomach triggers
stretch receptors Nutrients in small
intestine elicit hormones (for example, fat
elicits cholecystokinin, which slows gastric
emptying)
8
Energy In Kcal Intake

• Overriding hunger and satiety
• Stress eating and comfort foods
• External cues
• time of day
• availability
• sight, smell of food
• Environmental influences
• Example buffet, large portion size

9
Energy In Kcal Intake

• Sustaining satiation and satiety
• Nutrient composition
• Protein is most satiating
• Low-energy density / High-fiber foods also more
  satiating
• High-fat foods stimulate appetite
• low satiation
• strong satiety from SI (cholecystokinin)

10

100 kcal 9 g fat
837 kcal 71 g fat
100 kcal 5 g fat
55 kcal 3 g fat
For the same size portion, peanuts deliver more
than 15 times the kcalories and 20 times the fat
of popcorn.
For the same number of kcalories, a person can
have a few high-fat peanuts or almost 2 cups of
high-fiber popcorn. (This comparison used
oil-based popcorn using air-popped popcorn would
double the amount of popcorn in this example.)
11
837 kcal 71 g fat
55 kcal 3 g fat
For the same size portion, peanuts deliver more
than 15 times the kcalories and 20 times the fat
of popcorn.
12
100 kcal 9 g fat
100 kcal 5 g fat
For the same number of kcalories, a person can
have a few high-fat peanuts or almost 2 cups of
high-fiber popcorn. (This comparison used
oil-based popcorn using air-popped popcorn would
double the amount of popcorn in this example.)
13
Energy In Kcal Intake

• The Hypothalamus
• Control center for eating
• Integrates messages from brain, GI, liver
• Energy intake, expenditure, storage
• Gastrointestinal hormones- see list in margin

14
Energy Out Kcal expended

• Thermogenesis- heat generated when kcal broken
  down
• Total energy expenditure reflects 4 categories of
  thermogenesis
• Basal metabolism
• Physical activity
• Food consumption
• Adaptation

15
Components of Energy Expenditure Basal Metabolism

• Uses about two-thirds of energy expended in a day
• Metabolic activities
• All basic processes of life
• Basal metabolic rate (BMR)
• Variations for sleep and awake
• Weight
• Lean tissue
• Resting metabolic rate (RMR) not as precise

16
(No Transcript)
17
Components of Energy Expenditure Physical
Activity

• Voluntary movement of skeletal muscles
• Most variable component of energy expenditure
• Amount of energy needed depends on
• Muscle mass
• Body weight
• Activity
• Frequency, intensity, and duration

18
(No Transcript)
19
Components of Energy Expenditure Thermic Effect
of Food

• Use kcal to digest/absorb kcal
• Acceleration of GI tract functioning in response
  to food presence
• Requires energy, releases heat
• CHO 5-10, Fat 0-5, Protein 20-30
• Approximately 10 percent of energy intake
• High-protein foods gt high-fat foods
• Regular meal gt snacking

20
30-50 Physical activities
10 Thermic effect of food
50-65 Basal metabolism
21
Components of Energy Expenditure Adaptive
Thermogenesis

• Adapt to dramatic change in temperature, trauma,
  exertion (extra work done by body)
• Amount expended is extremely variable
• Not included in energy requirement calculations

22
Heat loss and energy expenditure relative to
surface area
23
Estimating Energy Requirements

• Gender
• BMR and LBM
• Growth
• Groups with adjusted energy requirements
• Age
• LBM, hormones, activity level

• Physical activity
• PA Factor
• Body composition body size
• Height
• Weight
• Height / weight
• file///E/Media/Animations/chapter8/08ht1.html

24
Quick Calorie Ranges

• To gain weight 35-45 kcal/kg
• To maintain weight 25-35 kcal/kg
• To lose weight 15-25 kcal/kg

25
Body Weight, Composition, Health

• Height/Weight indices unrelated to
  body composition
• Both in use health for nutritional assessment
• Subjective body image dictates behaviors
• Ideal Body Weight (IBW)
• Body Mass Index (BMI)
• Useful for epidemiological studies

26
Body composition is healthy
IBW / BMI says he is overweight
27
Defining Healthy Body Weight
28
Defining Healthy Body Weight

• Body mass index
• Relative weight for height
• BMI weight (kg)
• height (m)2
• Health-related classifications
• Healthy weight BMI 18.5 to 24.9
• Overweight BMI 25 to 29.9
• Obese BMI 30 to 39.9
• Morbidly Obese BMI gt 40

29

• Table 1 Proposed range of ideal weights for
  women, ages 25 and over,
• Height (with shoes) Weight in pounds (as
  ordinarily dressed)
•  
• Small frame Medium frame Large frame
•  
• 5' 0" 10513 11220 11929
• 5' 1" 10715 11422 12131
• 5' 2" 11018 11725 12435
• 5' 3" 11321 12028 12738
• 5' 4" 11625 12432 13142
• 5' 5" 11928 12735 13345
• 5' 6" 12332 13040 13850
• 5' 7" 12636 13444 14254
• 5' 8" 12939 13747 14558
• 5' 9" 13343 14151 14962
• 5' 10" 13647 14555 15266
• 5' 11" 13950 14858 15569
• 6' 0" 14153 15163 16074

30
(No Transcript)
31
Centers for Disease Control

• BMI is a fairly reliable indicator of body
  fatness for most people. BMI does not measure
  body fat directly, but research has shown that
  BMI correlates to direct measures of body fat,
  such as underwater weighing and dual energy x-ray
  absorptiometry (DXA).1, 2 BMI can be considered
  an alternative for direct measures of body fat.
  Additionally, BMI is an inexpensive and
  easy-to-perform method of screening for weight
  categories that may lead to health problems.
• BMI is used as a screening tool to identify
  possible weight problems for adults. However, BMI
  is not a diagnostic tool. For example, a person
  may have a high BMI. However, to determine if
  excess weight is a health risk, a healthcare
  provider would need to perform further
  assessments. These assessments might include
  skinfold thickness measurements, evaluations of
  diet, physical activity, family history, and
  other appropriate health screenings.

32
Centers for Disease Control

• Why does CDC use BMI to measure overweight and
  obesity?
• Calculating BMI is one of the best methods for
  population assessment of overweight and obesity.
  Because calculation requires only height and
  weight, it is inexpensive and easy to use for
  clinicians and for the general public.
• BMI inches and pounds formula
  weight (lb) / height (in)2 x
  703
• Example Weight 150 lbs, Height 5'5"
  (65")Calculation 150 (65)2 x 703 24.96

33
Assessing Your Weight and Health Risk

• BMI calculator file///E/Media/Animations/chapter
  8/08ht2.html
• Assessment of weight and health risk involves
  using three key measures
• Body mass index (BMI)
• Waist circumference
• Risk factors for diseases and conditions
  associated with obesity

34
What 2 BMI ranges look like

• http//www.flickr.com/photos/77367764_at_N00/14623940
  33/in/set-72157602199008819/
• http//www.flickr.com/photos/77367764_at_N00/14582014
  94/in/set-72157602199008819/

35
Clinical Ht/Wt Measures

• IBW Traditional ht/wt index
• Women 100 lbs 5 lbs/in gt 5 ft (54 120 lbs)
  
• Men 106 lbs 6 lbs/in gt 5 ft (62 190 lbs)
• UBW Usual Body Weight- average weight past 5-10
  yrs. Useless reference point unless person has
  been in good health
• ABW Adjusted Body Weight- necessary for setting
  kcal needs with OW/obese persons. IBW 1/3
  excess wt ABW

36
Excess Weight and Disease
37

Body Weights in U.S. Adults
Healthy weight (BMI 18.5 24.9)
Underweight (BMI lt 18.5)
Overweight (BMI 25 29.9)
Obesity (BMI 30 39.9)
Extreme obesity (BMI 40)
38
Body Fat and Its Distribution

• Important information for disease risk
• How much of weight is fat?
• Where is fat located?
• Ideal amount of body fat depends on person
• Normal wt man- 13-21
• Normal wt woman- 23-31
• Upper level for general disease risk
• Young men- 22 Men over 40- 25
• Young women- 32 Women over 40- 35

39
Body Fat and Its Distribution
40
Body Fat and Its Distribution

• Needing less body fat
• Some athletes 5-10 men, 15-20 women
• Needing more body fat
• Cold climate, pregnancy
• Fat distribution affects health risk
• Visceral fat / central obesity / apple-shaped
• Subcutaneous fat / lower body fat /
  pear-shaped

41
In healthy-weight people, some fat is stored
around the organs of the abdomen.
In overweight people, excess abdominal fat
increases the risks of diseases.
42
Upper-body fat is more common in men than in
women and is closely associated with heart
disease, stroke, diabetes, hypertension, and some
types of cancer.
Lower body fat is more common in women than in
men and is not usually associated with chronic
diseases.
43
Body Fat and Its Distribution

• Waist circumference
• Indicator of fat distribution central obesity
• Indicator of high risk for diabetes and CVD
• Women greater than 35 inches
• Men greater than 40 inches
• Waist-to-hip ratio
• Other techniques for body composition
• More precise measures

44
Body Fat and Its Distribution
45
Skinfold measures estimate body fat by using a
caliper to gauge the thickness of a fold of skin
on the back of the arm (over the triceps), below
the shoulder blade (subscapular), and in other
places (including lower-body sites) and then
comparing these measurements with standards.
46
Hydrodensitometry measures body density by
weighing the person first on land and then again
while submerged in water. The difference between
the persons actual weight and underwater weight
provides a measure of the bodys volume. A
mathematical equation using the two measurements
(volume and actual weight) determines body
density, from which the percentage of body fat
can be estimated.
47
Bioelectrical impedance measures body fat by
using a low-intensity electrical current. Because
electrolyte-containing fluids, which readily
conduct an electrical current, are found
primarily in lean body tissues, the leaner the
person, the less resistance to the current. The
measurement of electrical resistance is then used
in a mathematical equation to estimate the
percentage of body fat.
48
Air displacement plethysmography estimates body
composition by having a person sit inside a
chamber while computerized sensors determine the
amount of air displaced by the persons body.
49
Dual energy X-ray absorptiometry (DEXA) uses two
low-dose X-rays that differentiate among fat-free
soft tissue (lean body mass), fat tissue, and
bone tissue, providing a precise measurement of
total fat and its distribution in all but
extremely obese subjects.
50
Health Risks Associated with Body Weight Body
Fat
51
Risk increases as BMI rises
Risk increases as BMI declines
Mortality
15 20 25 30 35 40
Body mass index
52
Health Risks Associated with Body Weight Body
Fat

• Body weight and fat distribution correlate with
  disease risk and life expectancy
• Correlations are likelihoods, not causes
• Risks associated with being underweight
• Fighting against wasting diseases
• Menstrual irregularities and infertility
• Osteoporosis and bone fractures

53
Health Risks Associated with Underweight

• 1st question is WHY underweight?
• Smoking, substance abuse, body image
• Cancer, malnutrition, thyroid dz
• Risks associated with being underweight
• No reserves against wasting diseases
• Menstrual irregularities and infertility
• Osteoporosis and bone fractures

54
Health Risks Associated with Overweight and
Obesity

• Risks associated with being overweight
• Obesity is a designated disease
• Health risks include DM, Htn, CVD, sleep apnea,
  osteoarthritis, cancer, gallbladder dz, kidney
  stones, resp. problems, CHF
• Likely to be disabled / immobile in later years
• Costs billions
• 300,000 obesity-related deaths/year
• Weight Gain gt 20 lbs or 4 BMI units

55
Body mass index history and risk of type 2
diabetes results from the European Prospective
Investigation into Cancer and Nutrition
(EPIC)-Potsdam Study.

• Am J Clin Nutr. 2006 Aug84(2)427-33.
• Schienkiewitz A, Schulze MB, Hoffmann K, Kroke A,
  Boeing H.
• Department of Epidemiology, German Institute of
  Human Nutrition Potsdam-Rehbrücke, Germany.
  anja.schienkiewitz_at_mail.dife.de
• Severe weight gain defined as gt 4 BMI units

56

Body mass index history and risk of type 2
diabetes results from the European Prospective
Investigation into Cancer and Nutrition
(EPIC)-Potsdam Study.

• BACKGROUND Obesity and increases in body weight
  in adults are considered to be among the most
  important risk factors for type 2 diabetes.
• OBJECTIVE The objective was to evaluate and
  compare the associations between weight changes
  during 2 different periods of adult life and the
  risk of type 2 diabetes and age at diagnosis.

57
Body mass index history and risk of type 2
diabetes

• DESIGN The study included 7720 men and
• 10,371 women from the European Prospective
  Investigation into Cancer and Nutrition
  (EPIC)-Potsdam Study with information on weight
  history 390 men and 303 women of these
  participants received a clinical diagnosis of
  type 2 diabetes during 7 y of follow-up.
  Multivariate Cox regression models were used to
  estimate the relative risk (RR) of weight changes
  between ages 25 and 40 y and ages 40 and 55 y.

58
Body mass index history and risk of type 2
diabetes

• RESULTS RR estimates in men and women were
  slightly higher for each unit of BMI gain between
  ages 25 and 40 y men 1.25 (95 CI 1.21, 1.30)
  women 1.24 (1.20, 1.27) than between ages 40
  and 55 y men 1.13 (1.10, 1.16) women 1.11
  (1.08, 1.14). Severe weight gain between ages 25
  and 40 y was associated with a higher diabetes
  risk in men (1.5 times) and in women (4.3 times)
  than were stable weight in early adulthood and
  weight gain in later life, and it resulted in an
  average lower age at diabetes diagnosis in men (5
  y) and in women (3 y).

59
Body mass index history and risk of type 2
diabetes

• CONCLUSION Weight gain in early adulthood is
  related to a higher risk and earlier onset of
  type 2 diabetes than is weight gain between 40
  and 55 y of age.

60
Health Risks Associated with Excess Body Weight
Body Fat

• Cardiovascular disease
• High LDL, Low HDL, Htn, DM
• Metabolic Syndrome Inflammation
• Htn, High WC, TG, ser. Glucose low HDL
• Diabetes type II
• Central obesity
• Weight gains and body weight
• Cancer
• Especially hormone-mediated

61
Health Risks Associated with Body Weight Body
Fat

• Inflammation metabolic syndrome
• Change in bodys metabolism
• Cluster of symptoms
• Fat accumulation
• Inflammation
• Elevated blood lipids
• Promote inflammation

62
Double
Whammy
63
(No Transcript)
64
Highlight 8

• Eating Disorders

65
Eating Disorders

• Three disorders
• Anorexia nervosa
• Bulimia nervosa
• Binge eating disorder
• Prevalence of various eating disorders
• Causes
• Multiple factors
• Athletes and eating disorders

66
Female Athlete Triad

• Disordered eating
• Unsuitable weight standards
• Body composition differences
• Risk factors for eating disorders in athletes
• Amenorrhea
• Characteristics
• Osteoporosis
• Stress fractures

67
Female Athlete Triad
68
Other Dangerous Practices of Athletes

• Muscle dysmorphia
• Characteristic behaviors
• Similarities to others with distorted body images
• Food deprivation and dehydration practices
• Impair physical performance
• Reduce muscle strength
• Decrease anaerobic power
• Reduce endurance capacity

69
Anorexia Nervosa

• Distorted body image
• Central to diagnosis
• Cannot be self-diagnosed
• Malnutrition
• Impacts brain function and judgment
• Causes lethargy, confusion, and delirium
• Denial
• Levels are high among anorexics

70
Anorexia Nervosa

• Need for self-control
• Protein-energy malnutrition (PEM)
• Similar to marasmus
• Impact on body
• Growth ceases and normal development falters
• Changes in heart size and strength
• Other bodily consequences

71
Anorexia Nervosa

• Treatment
• Multidisciplinary approach
• Food and weight issues
• Relationship issues
• After recovery
• Energy intakes and eating behaviors may not
  return to normal
• High mortality rate among psychiatric disorders

72
Anorexia Nervosa
73
Bulimia Nervosa

• Distinct and more prevalent than anorexia nervosa
• True incidence is difficult to establish
• Secretive nature
• Not as physically apparent
• Common background characteristics of bulimics

74
Bulimia Nervosa

• Binge-purge cycle
• Lack of control
• Consume food for emotional comfort
• Cannot stop
• Done in secret
• Purge
• Cathartic
• Emetic
• Shame and guilt

75
Bulimia Nervosa
76

Stepped Art
Fig. H8-2, p. 266
77
Bulimia Nervosa

• Physical consequences of binge-purge cycle
• Subclinical malnutrition
• Effects
• Physical effects
• Tooth erosion, red eyes, calloused hands
• Clinical depression and substance abuse rates are
  high

78
Bulimia Nervosa

• Treatment
• Discontinuing purging and restrictive diet habits
• Learn to eat three meals a day
• Plus snacks
• Treatment team
• Length of recovery
• Overlap between anorexia nervosa and bulimia
  nervosa

79
Bulimia Nervosa
80
Binge-Eating Disorder

• Periodic binging
• Typically no purging
• Contrast with bulimia nervosa
• Compare with bulimia nervosa
• Feelings
• Differences between obese binge eaters and obese
  people who do not binge
• Behavioral disorder responsive to treatment

81
Eating Disorders in Society

• Society plays central role in eating disorders
• Known only in developed nations
• More prevalent as wealth increases
• Food becomes plentiful
• Body dissatisfaction
• Characteristics of disordered eating