The document discusses obesity, defining it as a condition of excessive body fat that is associated with various health risks, and examines its causes such as overeating, physical inactivity, and genetic factors; it also explores strategies for weight loss through diet, exercise, behavior modification, and in some cases medications, noting that most people regain lost weight without long-term lifestyle changes and support.

1. Obesity

2. Overweight and Obesity
• Overweight: body weight
that exceeds some
average for stature,
perhaps age.
• Overfat: body fat that
exceeds an age- and/or
gender appropriate
average by some amt.
• Obesity: overfat
condition that
accompanies
components of obese
syndrome.

3. Obese Syndrome Components
• Glucose intolerance
• Insulin resistance
• Dyslipidemia
• Type 2 diabetes
• Hypertenision
• Elevated plasma leptin
concentration
• Increased visceral adipose
tissue
• Increased risk of CHD &
some cancers

4. Call to Action:
Impact
Individuals with a BMI
of 35- 40 kg/m2 are at
high risk
Individuals with a BMI >
40 kg/m2 are at very
high risk

5. Obesity: A Global Epidemic
• Why is obesity accelerating in
developing countries?
• Increased consumption of
energy-dense, nutrient poor
foods combined with reduced
physical activity.

6. Obesity: A Global Epidemic
• What is the prevalence of overweight and obesity
in the United States? 66% & 31%
obesity
trend

7. 2000
Obesity Trends* Among U.S. Adults
BRFSS, 1990, 2000, 2010
(*BMI ³30, or about 30 lbs. overweight for 5’4” person)
2010
1990
No Data <10% 10%–14% 15%–19% 20%–24% 25%–29% ≥30%

8. Call to Action: Impact
The State of Obesity: https://stateofobesity.org/healthcare-costs-obesity/
Direct healthcare costs:
$147-210 billion / year
$506 / employee with
obesity / year

9. How many receive
obesity treatment by
PCP?
Obesity diagnosis: 29%
Call to Action
Bleich SN, Pickett-Blakely O, Cooper LA. Physician practice patterns of obesity diagnosis
and weight-related counseling. Patient Educ Couns. 2011;82(1):123-129.
.
Waring ME, Roberts MB, Parker DR, Eaton CB. Documentation and
management of overweight and obesity in primary care. J Am Board Fam
Med. 2009;22(5):544-552

10. How many receive
components of obesity
treatment treatment by
PCP?
Call to Action
Waring ME, Roberts MB, Parker DR, Eaton CB. Documentation and management of overweight and obesity in primary care. J Am Board Fam Med. 2009;22(5):544-552

11. Causes of Obesity
• Obesity is a long term
process.
• Obesity frequently begins
in childhood. Obese
parents likely have
overweight children.
• Regardless of final body
weight as adults,
overweight children
exhibit more illnesses as
adults than normal kids.
You gonna
finish that?

12. Causes of Obesity
• Excessive fatness also
develops slowly
through adulthood,
most weight gain
occurring between
ages 25 to 44 yrs.
• Typical American man
& woman gain .5 to
1.8 lb/year until 60.

13. Causes of Obesity
• Overeating and Other Factors
• Factors that cause human obesity:
genetics, environmental, metabolic, behavioral, social
• Factors that predispose a person to gain
excessive weight gain.
• Eating patternsEating environment
• Food packaging Food availability
• Body image Physical inactivity
• Basal body temp Dietary thermogenesis
• Fidgeting Biochemical differences
• Quantity & sensitivity to satiety hormones

14. Overeating and Other Factors
• Nutrition transition shifts in dietary structure toward higher
energy density with greater fat and added sugars, greater
saturated fat, reduced complex CHO and fiber, and reduced
fruits & vegetables.
• Food consumption expressed in kCal per capita per day has
increased.
• Decreased energy expenditure for all populations of the world.

15. Causes of Obesity
• Characteristics of fast food
linked to increased adiposity:
• Higher energy density
• Greater saturated fat
• Reduced complex carbohydrates
& fiber
• Reduced fruits and vegetables.

16. Causes of Obesity
• Genetics plays a role.
• How much variation in
weight gain among
individuals can be
accounted for by genetic
factors?
• Familial association is not
proof of genetic
inheritance-families share
eating & exercise habits.
• Largest transmissible
variation is cultural.

17. Causes of Obesity
• A Mutant Gene?
• What is leptin?
• A satiety hormone that influences the appetite control
in the hypothalamus.
• A defective gene may cause inadequate leptin
production.
• The brain receives an under assessment of body’s
adipose stores & urge to eat.

18. Causes of Obesity
Normally leptin blunts the urge to
eat when caloric intake maintains
ideal fat stores.
In essence, leptin availability, or
its lack, affects the
neurochemnistry of appetite and
the brain’s dynamic “wiring” to
possibly impact appetite and
obesity in adulthood.
Leptin alone does not determine
obesity or explain why some
people eat whatever they want
and gain little weight while
others become overfat with the
same caloric intake.

19. Causes of Obesity
A defective ob gene causes
inadequate leptin production.
Thus, the brain receives an
under assessment of body’s
adipose stores and urge to
eat.
May be defective leptin
receptor action.
How does Leptin affect body
fat?
• Stimulates chemicals that
suppress appetite
• Reduce levels of chemicals that
stimulate appetite.

20. Causes of Obesity
• Physical Inactivity: an
important component
• Each hour increase in
TV by adolescents 2%
increase obesity.
• Adults 15 & over spent
average 2.73 hr/day
watching TV in 2010.
• Each hour increase in
TV by adults increase
risk of death 11%.

21. Obesity
• Health Risks of Obesity
• Primary risk factor for
coronary heart disease.
• Associated with HTN, DM,
dyslipidemia, &
cerebrovascular disease.
• Obesity-related medical
complications account for
10% of national health
care.

22. Obesity
• How Much Fat is TOO Much?
• List three criteria for evaluating a person’s level of fatness.
• % Body Fat
• Fat Patterning
• Fat Cell Size and Number

23. Percent Body Fat
• Overfatness corresponds to
any body fat value 5% above
the average value for age &
sex.
• Borderline obesity in young
man > 20 & in young woman
>30%.
Standard Men Women
Essential 3-5 11-14
Athletic 8-12 12-18
Acceptable 13-20 19-25
Overfat 21-25 26-30
Obese >25 > 30

24. Fat Patterning
• Adipocytes from some
locations (gluteal & femoral)
efficiently capture excess
nutrients from the blood-stream
for storage, while others
accumulate TGs but readily
release them for use by other
tissues.

25. Fat Patterning
• Visceral (intra-
abdominal) adipose
tissue (VAT) relates to
an altered metabolic
profile.
• Abdominal fat
described as android
(apple) has higher
health risk than gynoid
(pear) obesity.

26. Fat Patterning
• Give an objective
standard for
establishing male- and
female-pattern obesity.
• Male > .95 W:H ratio
• Female > .80 W:H

27. Fat Cell Number and Size
• Increases in adipose tissue
occurs in two ways:
1. Fat cell hypertrophy
2. Fat cell hyperplasia

28. Fat Cell Number and Size
• After reaching a biological upper limit for fat cell size, cell number
becomes a key factor that determines obesity.

29. Weight Control
• What is the prognosis for long term weight
control?
• Participants who remain in supervised weight
loss program regain almost all within 5 years.

30. Weight Control
• One pound of fat
contains 3,500 kcal
• Unbalance the Energy
Equation (First Law
Thermodynamics)
1. Reduce kcal intake
2. Increase kcal output
3. Reduce intake and
increase output

31. Altering the Energy Balance
• Total energy intake (not macronutrient mixture)
determines effectiveness of weight loss with diet.
• Rapid weight loss during first few days comes
mainly from body water loss and glycogen
depletion.
• Continued weight reduction occurs at expense of
greater fat loss per unit weight loss.

32. Altering the Energy Balance
• Resting Metabolic
Rate Lowered.
• Blunted metabolism
conserves energy
causing diet to
become progressively
less effective.
• Could lead to difficulty
losing weight.

33. Fat Cell Size and Number
• What happens to fat cell size and fat cell number
when adults lose weight?
• Fat cells shrink to a smaller size than adipocytes of
nonobese people, number remains same.
• The large # of relatively small adipocytes may relate
to appetite control; person craves food, overeats &
gains lost weight.
• Total number of fat cells increases 3 general periods:
Last trimester pregnancy, 1st year life, adolescence

34. What works?
SELF-HELP: 45% of National Weight Control Registry participants lost
weight without program or professional help
PROFESSIONAL-LED LIFESTYLE INTERVENTION:
Many different models proven effective
WEIGHT MANAGEMENT MEDICATIONS:
Underutilized. Many patients w/ obesity could benefit.
WEIGHT LOSS SURGERY:
Most significant & sustained health
improvements. Underutilized.
Relatively low-risk surgery.

35. Setting Expectations
Behavioral intervention:
Initial weight loss goal of 5 -10% typical
Pharmacologic therapy + behavioral therapy:
10 - 15% is a very good response
Weight loss > 15% is considered excellent
response

36. What works?
• USPSTF Grade B recommendation: screen all adult patients
for obesity and offer intensive counseling and behavioral
interventions
• CMS definition of intensive behavioral therapy for obesity:
• - Weekly visits for Month 1;
• - Biweekly visits for months 2-6;
• - Monthly visits for months 7-12
Coding: G0447 if spend >15 minutes counseling
5A’s model
BOTTOM LINE:
At least monthly visits
Preventive Services Task Force. Screening for obesity in adults: recommendations and rationale. Ann Intern Med 2003;139:930-932
CMS Decision Memo for Intensive Behavioral Therapy for Obesity (CAG-00423N)

37. Fat Cell Size and Number
• In non-obese subjects with moderate weight gain, adipocyte
size increased substantially with no change in cell number.
• Weight gain among severely obese, new adipocytes develop in
addition to hypertrophy of existing cells.

38. Select a Diet Program
Method Principle Disadvantage
Low CHO –
ketogenic
Increased ketone excretion
removes energy-containing
substances from body.
Ketogenic
High fat intake
contraindicated.
High
protein
Low caloric intake favors
negative energy balance.
Elevated thermic effect.
Expensive, repetitious;
difficult to maintain,
dehydrates.
Semi-
starvation
Decreased energy input
assures negative balance.
Possible malnutrition,
lethargy, LBM.
High CHO,
low fat
Low carbohydrate favors
negative balance.
Initial water retention.

39. Exercising to Tip Energy Balance
• Increased physical activity combined with dietary
restraint maintains weight loss more effectively than
caloric restriction alone.
• For previously sedentary, overweight, moderate
increases in physical activity do not necessarily
increase food intake.
• Recommend minimum of 3 days per week.
Intensity individualized, minimum 300 kcal/session

40. Diet Plus Exercise
• Combining exercise
and diet offers more
flexibility for weight
loss.
• Exercise facilitates fat
mobilization from
adipose depots and fat
catabolism. Preserves
fat free body mass,
blunts decrease in
RMR, improves insulin
sensitivity.

41. Diet Plus Exercise
The Ideal Combination
• Exercise enhances fat
mobilization from
body’s adipose depots
and fat catabolism by
active muscles.
• Protects against
protein loss in skeletal
muscle and improves
insulin sensitivity.

42. Maintenance of Goal Body Weight
• Most weight loss occurs
during first 6 months.
Up to 85% those
starting a weight loss
program drop & regain.
• IOM recommend that
obese reduce initial
body weight by 5% to
15% as realistic.

43. Maintenance of Goal Weight
• Selective fat reduction at
specific body areas by
spot reduction does NOT
work.
• Exercise stimulates fatty
acid mobilization through
hormones and enzyme
action that target fat
depots throughout the
body.

44. Gaining Weight
• Resistance training complemented by well-balanced diet
increases muscle mass.
• If all calories consumed in excess of energy requirement during
resistance training would go towards muscle growth, 2000 to
2500 extra calories would support 0.5 kg increase in lean
tissue.
• Intense aerobic training will detract from maximal increases in
muscle mass.

45. Assist: 5-10% Weight
Loss
Results in significantly increased odds of achieving:
• 0.5% point reduction in HbA1c
• 5-mmHg decrease in diastolic & systolic blood pressure
• 5 mg/dL increase in HDL cholesterol
• 40 mg/dL decrease in triglycerides
(Compared to weight
stable patients)
Odds even greater in
those who lost 10-15%

46. Assist: 5-10% Weight
Loss
Often achievable through behavioral
interventions alone
Patients feel it is realistic & achievable
<10% does not seem to trigger defense of
“set point”

47. • Emphasize
the benefits
of losing 5-
10%
Assist
300
lbs
180
lbs
270
lbs

48. Strategies for achieving 5-10%
Weight Loss
What works best? The plan that is sustainable
long-term
Evidence for:
Low-fat or low-carb
Mediterranean diet
Keys: avoid hunger, make it easy
Gardner, Trepanowski, Del Gobbo, et al. Effect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults
and the Association With Genotype Pattern or Insulin Secretion: The DIETFITS Randomized Clinical Trial. JAMA, 2018.
Shai, I., Schwarzfuchs, D., Henkin, Y., Shahar, D.R., Witkow, S., Greenberg, I. et al, Weight loss with a low-carbohydrate,
Mediterranean, or low-fat diet. N Engl J Med. 2008;359:229–241.

49. Strategies for achieving 5-10%
Weight Loss
Caloric deficit of 250-500 calories/day
But there are some pitfalls…
Don’t:
Overly focus on # of calories
without also paying attention
to quality of calories
Do:
Set specific behavioral goals &
track progress closely with
regular check-ins

50. Measurable
Example #1: I want to lose 10 lbs over the
next 3 months
Example #2: I will eat 2 servings of
vegetables, 5 out of 7 days per week. I will
track using notes section on phone and
review weekly by myself and monthly with
PCP. Next appointment: ___
Example #3: I will walk 4/5 weekdays
during lunch break for 20 minutes. I will
track using physical calendar displayed at
my desk. Will review weekly by myself and
monthly with PCP. Next appointment: ___
TIP: Ask them to WRITE their
goal down and read back to you

51. DO / INCREASE AVOID / DECREASE
Stop eating when full Going hungry
Consistent meal schedule Skipping meals
Follow the Healthy Eating Plate
model
Grazing between meals
Eating late at night
Processed foods like canned
meats or frozen meals
White (sugar, breads, pasta)
Sugary drinks
Alcohol
Trans fats or saturated fats (butter,
red meats, fried foods, chips)

52. • Healthy fats, not low-fat
• Limit red meat, cheese,
dairy and processed
meats
• More specific directions re
quality of calories

53. Strategies for maintaining
weight loss: NWCR
1. Physical activity becomes extremely
important
77%: 60 mins daily, walking most frequently cited
2. 78%: eat breakfast daily
3. 77%: weigh at least weekly
Catch slips before they turn into relapse
4. Consistent eating habits, independent weekday vs
weekend

54. Weight Management Medications
BMI >30
BMI >27 with obesity-related comorbidity
Khera R, Murad MH, Chandar AK, et al. Association of pharmacological treatments for obesity with weight loss and
adverse events: A systematic review and meta-analysis. JAMA 2016; 315:2424. doi: 10.1001/jama.2016.7602

55. Weight Management Medications
BMI >30
BMI >27 with obesity-related comorbidity
FDA-Approved
Weight
Management
Medications
Phentermine-
Topiramate
(Qsymia)
Liraglutide
(Saxenda,
Victoza)
Lorcaserin
(Belviq)
Naltrexone
SR-
Bupropion SR
(Contrave)
Orlistat
(Alli/Xenical)
Class/Mechanis
m
Anorexiant;
Anticonvulsant
; Sympathomi-
metic
Glucagon-Like
Peptide-1
(GLP-1)
Receptor
Agonist
Serotonin 5-
HT2C
Receptor
Agonist
Dopamine/Nor
-epinephrine-
Reuptake
Inhibitor;
Opioid
Antagonist
Lipase inhibitor
Avg Weight Loss
at 1 year
10% 9% 6% 6% 2-3%
Side Effects CV, CNC, GI,
Resp
CV, CNS, GI,
Local
CNS, MSK,
Resp
CV, CNS,
Endo
CNS, ID, GI
Cost (month) $220 $288 $317 $290 $50

56. Bariatric Surgery

57. What Works
57
Weight loss:
Lifestyle: 5-10%
Medications: 5-20%
Surgery: 30-40%

58. Assist: Key Take-Aways
1. Emphasize benefits of losing 5-10%
2. Help patients set realistic long-term weight loss goals
AND short-term behavioral SMART goals
3. Reward progress!
4. Prescribe & Refer

59. Future Steps
• Obesity is
heterogeneous
disease with
heterogeneous
responses
• Combination therapies
• Obesogenic
environment
• Primary prevention

60. Conclusions

61. Illustration References
• McArdle, William D., Frank I. Katch, and Victor L. Katch. 2000.
Essentials of Exercise Physiology 2nd ed. Image Collection.
Lippincott Williams & Wilkins.
• Plowman, Sharon A. and Denise L. Smith. 1998. Digital Image
Archive for Exercise Physiology. Allyn & Bacon.