CHILDHOOD OBESITY
From the 27th Annual Las Vegas Seminars: Pediatric Update, presented November 17-20, 2005,
by the American Academy of Pediatrics, California Chapters 1,2,3, and 4
William H. Dietz, MD, PhD, Director, Division of Nutrition and Physical Activity,
the Centers for Disease Control and Prevention, Atlanta
| PREVENTION OF CHILDHOOD AND ADOLESCENT OBESITY
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Factors Related to Onset of Obesity
| Overview: altered dietary intake, decreased physical activity, and increased inactivity each independent causes of obesity
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| Shifts in food practices in United States: increased consumption of fast foods; reduced frequency of family meals;
restrained eating and meal skipping (paradoxically, increases risk for weight gain); increased consumption of soft
drinks; variety of products in supermarkets (relationship between variety of foods offered and food intake); increased
portion sizes
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| Decreased daily physical activity: in school (9th-12th graders)—in 1991, 42% of schools offered daily physical
education (by 1999, 29%); disconnected neighborhood network—people live in cul-de-sacs separated from schools
and shopping areas; 10 yr ago, 20% of children walked to school (today, <12%); increased inactivity—inactivity and
activity have independent effects on prevalence of obesity
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| Daily television viewing: according to Kaiser Family Foundation, 17% of children and youth watch television ≥5 hr/
day; linear relationship between amount of television watched and prevalence of overweight; in addition, more severely
overweight children watch more television (causal link less certain); 65% of children have television in bedroom
(≈25% of 2-yr-old children)
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Behavior-Change Strategies
| Interventions directed at reducing television time: one of most effective ways of reducing existing overweight or
preventing excessive weight gain; study by Epstein (1995)—4-mo intervention aimed at increasing physical activity or
reducing sedentary time (predominantly television time); greater weight loss in group reinforced for reducing television
time compared to group reinforced for exercise
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| Increased physical activity: does not cause substantial increase in weight loss, but reduces obesity-associated comorbidities
(particularly glucose intolerance and hyperlipidemia); if patient obese and inactive, and triglycerides elevated, increased
physical activity improves triglyceride level, raises high-density lipoprotein (HDL), and lowers low-density
lipoprotein (LDL)
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| Promotion of breast-feeding: 3 meta-analyses show that breast-feeding reduces risk for early childhood overweight
(risk factor for severe adult disease later in life)
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| Promising interventions: fruit and vegetable consumption affects satiety based on volume of foods consumed (satiety
not regulated by calories); foods of low caloric density (high water content) more filling; data lacking that increasing
fruits and vegetables helps reduce weight or that people who have increased fruit and vegetable intake have lower risk
of being obese; several studies link soft drink consumption to increased weight gain; portion size has robust impact on
food intake; the larger the portion individual exposed to, the more likely to overeat
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Intervention Sites
| School-based interventions: physical education classes; enhanced access using outreach to recreational facilities; urban
design and land use to promote physical activity; walk-to-school programs; media curricula and television turnoffs
(study by Robinson)—effect of 18-lesson elementary school curriculum on body mass index (BMI); in control
group, 0.7-unit increase in BMI (0.3-unit increase in intervention schools); additional reduction in waist circumference
and skin-fold thickness; television time substantially reduced in intervention group; competitive foods—“pouring contracts”
euphemism for contracts to sell soft drinks from vending machines; win-win strategy allows school to maintain
vending machines, but provides better choices for children; comprehensive school-based intervention (Planet
Health)—program in Boston middle schools; focus on reducing fat intake, increasing physical activity, increasing fruit
and vegetable consumption, and reducing television time; positive impact on overweight girls (not overweight boys)
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Community-Based Approaches
| Communication strategies: one problem is lack of consistent messages across settings; specific language—billable
code for “obesity” not “overweight”; BMI at 95th percentile is 30 in young adult (criteria for obesity; morbid obesity at
99th percentile); “diet” acceptable medical term, but most people view term negatively (emphasize “better nutrition”);
“exercise” suggests repetitious, boring activities (promote “physical activity”); “healthy” associated with food that is
difficult to prepare, and that does not taste good (“wholesome” does not have same connotation)
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| “Verb: it’s what you do”: public information campaign targeted 9- to 13-yr-olds; goal to get children to choose their
“verb” (ie, choose their activity); separate ads developed for 5 major ethnic groups; children repeatedly exposed to ads
increased levels of physical activity
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| Healthy Communities (recommendations from Institute of Medicine [2004])
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 | Mobilization of diverse coalitions in community: focus on barriers for high-risk populations, particularly Native Americans,
Hispanics, and blacks
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| Enhancement of built environment: revise city planning practices; improve opportunities for walking and bicycling to
schools; better access to healthy foods, through, eg, farmer’s markets or supermarkets in inner city
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| TREATMENT OF CHILDHOOD OBESITY
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| Prevalence of overweight in United States: 2-fold increase among 6- to 11-yr-olds between 1980 and 2000 (3-fold increase
in adolescents); significant disparities among adolescent boys; Hispanic boys have highest prevalence of BMI
>95th percentile (followed by black girls); Hispanic girls and black boys comparable
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| Morbid obesity (BMI at 99th percentile): ≥3 standard deviations above mean; for boys, BMI ≈35 (among girls,
≈40); ≈2% of adolescent population has BMI ≥40; morbidly obese patients need aggressive therapy; important increase
in frequency of 2 or 3 comorbidities at BMI >98th percentile
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| Consequences of childhood and adolescent obesity: ≈60% of overweight 5- to 10-yr-old patients have at least 1 additional
risk factor for cardiovascular disease; common—hyperlipidemia; high LDL, low HDL, and high triglycerides; abnormal
glucose metabolism (elevated glucose or insulin level) and elevated blood pressure (BP); 25% of pediatric patients
have ≥2 complications; adipose tissue important source of cytokines and other inflammatory mediators (cytokines play role
in hepatic steatosis and may contribute to asthma); hepatic steatosis probably most prevalent consequence of overweight in
childhood
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| Impact of childhood BMI ≥95th percentile on adult obesity (BMI ≥30): overweight at <8 yr of age may have significant
impact on adult disease (if early obesity persists, average adult BMI 41.7); only 25% of obese adults overweight
as children
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| Role of physical activity in weight control: dose of physical activity necessary to prevent obesity unknown; current
pediatric recommendation moderate physical activity 60 min daily (derived from data on cardiovascular disease); in
adults, dose to maintain weight after weight loss ≈1 hr/day; in adult literature, relatively modest impact of physical activity
on weight loss; in 12-wk period, if physical activity added to dietary therapy, patients achieve additional 1 kg
weight loss; physical activity reduces obesity-associated comorbidities; important impact on glucose tolerance and lipid
levels (modest impact on BP)
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| Self management: key to success in any age group (patient-centered care rather than provider-directed care)
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| Clinical diagnoses associated with obesity
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| Congenital disorders: short stature (Prader-Willi syndrome; myelodysplasia; Cushing’s syndrome); gonadal dysfunction
or dysgenesis (Prader-Willi syndrome; polycystic ovary disease); mental retardation (Prader-Willi syndrome;
Bardet-Biedl syndrome); somatic disorders (rare); genetic disorders increase susceptibility to obesity
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| History: headaches and diplopia may be clues to pseudotumor cerebri; daytime somnolence suggests sleep apnea; abdominal
pain (gallbladder disease); urinary frequency and nocturia (type 2 diabetes); hip pain (slipped capital femoral
epiphysis; some children present with painless limp)
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| Physical examination: hirsutism indicator of polycystic ovary disease; funduscopic examination important, particularly
for individuals with headaches; abdominal tenderness may suggest gallbladder disease and need for ultrasonography;
gallbladder disease (particularly stones) common after rapid weight loss in adults; range of motion for slipped capital
femoral epiphysis; bowing in Blount’s disease clearly associated with weight
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| Laboratory tests: controversial (unlikely to change therapy); consider—urinalysis; lipoprotein profile; fasting insulin
or glucose; liver function tests
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| Behavioral interventions: focus on diet, physical activity, and inactivity
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| Successful strategies for weight maintenance: adults who have lost ≈20 kg and maintained loss >1 yr—low fat
intake; eating breakfast; expending 400 kcal/day (requires ≈1 hr of moderate physical activity); monitoring weight at least
once per week; activity need not be continuous and need not be vigorous (moderate physical activity includes brisk walking
or outdoor play); skipping breakfast used as weight control strategy by adolescent girls, but, paradoxically, it predisposes
pediatric patients to weight gain); if weight monitoring done in neutral fashion (not punitive), likelihood of eating
disorders low
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| “Get More” office poster: developed by Kaiser Permanente and tested in pediatric population; focus on getting more
energy; to get more energy—play hard for 30-60 min/day; cut back on television and video games (recommendation 1
hr/day); remove television from bedroom; 5 helpings of fruits and vegetables daily (preceded more recent dietary
guidelines); reduce intake of sodas and juice drinks (≤1 can or small cup daily; drink water when thirsty)
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| Motivational interview techniques: begin with open question—how concerned are you about your weight (or your
child’s weight)? has weight caused any difficulties for you? (gets at patient’s perspective; need to tie weight to values;
self-management requires collaboration of provider and patient; external motivation—pediatricians or providers telling
patients what to do; internal motivation—better approach; helping patients understand how to solve their own
problems; continuing conversation—on scale of 1 to 10, 10 being very interested, how interested are you in changing
your weight or behavior related to your weight? if patient not very interested—what would it take to make you more
interested? if I told you weight was going to lead to adverse health effects, would that change your mind?; patient not
ready to change—it sounds like you’re not ready to make a change; perhaps you can think about what we’ve talked
about with respect to adverse health effects of weight, and we can talk about it again when I see you next; ready to
change—ask what patient or parent might want to do about problem
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| Facilitating change: environmental controls—food or soft drink not in home not going to be consumed or cause battles;
set clear goals—“if you can’t count it, you can’t change it”; monitor and reward success—most important reward
is praise and attention
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| Pharmacologic therapy (overview): reserved for severely overweight patients; indications in adolescents—200%
of ideal weight; failure of more conservative therapy
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| Specific medications: orlistat—pancreatic lipase inhibitor; adverse effects (reduced absorption of fat-soluble vitamins;
if dose too high, fatty liquid leaks from rectum); sibutramine—serotonin reuptake inhibitor; does not have adverse
cardiovascular risk factors associated with fenfluramine-phentermine combination; rimonabant—on horizon;
cannabinoid-1 receptor blocker; effective against obesity and tobacco use; twice weight loss associated with sibutramine
and orlistat; caveat—these drugs still experimental in adolescents
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| Behavioral therapy and sibutramine in adults (study by Berkowitz): ≈5% greater weight loss achieved at 6 mo
(10% change in BMI); reduced risk for obesity-associated comorbidities (eg, type 2 diabetes and cardiovascular disease);
but speaker’s goal for adolescents normal weight rather than modest weight loss
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| Bariatric surgery: adults with BMI >40 and significant comorbidity recommended for bariatric surgery; experience in
adolescents limited; significant potential complications of surgery; recommended criteria in adolescents (Inge)—1)
BMI ≥40 with, eg, sleep apnea, type 2 diabetes, or pseudotumor cerebri, or 2) BMI ≥50 with, eg, hyperlipidemia; skeletal
maturity; failure of more conservative therapy; rate of significant complications ≈20%; Roux-en-Y gastric
bypass—separates stomach using staples to create ≈1-oz gastric pouch and brings limb of jejunum up to create anastomosis;
weight loss due to reduced gastric volume and aversion (overeating causes abdominal pain and vomiting); 50%
to 60% of initial body weight can be lost (over time, weight loss plateaus); adjustable gastric banding—newer approach;
subcutaneous port implanted under skin; saline injected to adjust size of band; hunger may be comparatively
greater after lap banding because ghrelin levels in lower stomach not affected; both procedures—can be performed
laparoscopically
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Educational Objectives
| The goal of this program is to educate the listener about managing obesity in children and adolescents. After hearing and
assimilating this program, the clinician will be better able to:
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| 1. Identify factors related to the onset of obesity.
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| 2. Describe behavior-change strategies to prevent or manage obesity.
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| 3. Describe effective techniques for communicating with patients about weight management.
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| 4. Describe newer medications for managing obesity.
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| 5. Recognize indications for bariatric surgery.
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Discussed on This Program
Fenfluramine HCl [Pondimin](withdrawn)
Orlistat [Xenical]
Phentermine HCl [Adipex-P, Ionamin, Pro-Fast HS, Pro-Fast SA, Pro-Fast SR]
Rimonabant (SR 141716) [investigational]
Sibutramine HCl [Meridia]
Resources
cdc.gov/nccdphp/dnpa
cdc.gov/nccdphp/dash
cdc.gov/youthcampaign
VERBnow.com
VERBparents.com
heathierus.gov/steps
Suggested Reading
Barlow SE, Dietz WH: Management of child and adolescent obesity. Summary and recommendations based on reports
from pediatricians, pediatric nurse practitioners, and registered dieticians. Pediatrics 110:236, 2002; Berkowitz RI et
al: Behavior therapy and sibutramine for the treatment of adolescent obesity: a randomized controlled trial. JAMA
289:1805, 2003; Dietz WH, Gortmaker SL: Preventing obesity in children and adolescents. Annu Rev Public Health
22:337, 2001; Dietz WH, Robinson TN: Clinical practice. Overweight children and adolescents. N Engl J Med 352,
2100; Dietz WH: Overweight in childhood and adolescence. N Engl J Med 350:855, 2004; Dietz WH: Physical activity
recommendations: where do we go from here? J Pediatr 146:719, 2005; Dietz WH: The obesity epidemic in young
children. Reduce television viewing and promote playing. BMJ 322:313, 2001; Inge TH et al: A critical appraisal of evidence
supporting a bariatric surgical approach to weight management for adolescents. J Pediatr 147:10, 2005; Jeffery
RW et al: An environmental intervention to increase fruit and salad purchases in a cafeteria. Prev Med 23:788, 1994;
Krakoff J et al: Incidence of retinopathy and nephropathy in youth-onset compared with adult-onset type 2 diabetes.
Diabetes Care 26:76, 2003; Levin S et al: Physical activity and body mass index among US adolescents: youth risk behavior
survey, 1999. Arch Pediatr Adolesc Med 157:816, 2003; Resnicow K et al: Motivational interviewing in health
promotion: it sounds like something is changing. Health Psychol 21:444, 2002; Robinson TN: Reducing children’s
television viewing to prevent obesity: a randomized controlled trial. JAMA 282:1561, 1999; Serdula MK et al: Weight
loss counseling revisited. JAMA 289:1747, 2003.
Faculty Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial
relationship with the manufacturer or provider of any commercial product or service discussed. For this issue,
the faculty reported nothing to disclose.
Dr. Dietz was recorded at the 27th Annual Las Vegas Seminars: Pediatric Update, presented November 17-20, 2005,
in Las Vegas by the American Academy of Pediatrics, California Chapters 1,2,3, and 4. The Audio-Digest Foundation
thanks Dr. Dietz and the Academy for their cooperation in the production of this program.
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