Can Eating Disorders and Overweight Prevention Initiatives Be Integrated? Notes From the Field S. Bryn Austin, ScD Division of Adolescent Medicine Childrens.

Can Eating Disorders and Overweight Prevention Initiatives

Be Integrated? Notes From the Field

S. Bryn Austin, ScD

Division of Adolescent Medicine

Children’s Hospital Boston

Harvard Medical School

Overview of Presentation

• Background • Prevalence and sequelae of eating disorders

and obesity • Prevention intervention research for eating

disorders and obesity

• Planet Health Study

• Implications for prevention research, policy

Prevalence of Eating Disorders and Obesity Among Females

0.5%2.0%

4.0%

8.0%

14.0%15.5%

0%

5%

10%

15%

20%

Anorexia Bulimia BingeEating

Disorder

Vomit/LaxAbuse

EatingDisorder Sx

Obesity (12-19 y)

Health Consequences of Eating Disorders

• Electrolyte abnormalities• Amenorrhea, impaired growth• Osteoporosis• Cardiac impairment• Dental erosion• Impaired psychosocial and cognitive

functioning

Health Consequences of Obesity

• Linked with multiple health problems• Diabetes, hypertension, cardiovascular

disease, osteoarthritis, cancer

• Linked with eating disordered behaviors• Vomiting and laxative use • Bulimia nervosa• Binge eating disorder

Eating Disorders Preventive Interventions

• Over 40 preventive intervention studies

• Majority found improvement in knowledge and/or attitudes

• A few studies found positive behavior change

Eating Disorders Preventive Interventions

• Five randomized controlled trials (RCT) with early adolescents• RCT: strongest design for intervention study

• 6th-8th grade girls, some include boys

• Study sizes ranged from 86 to 1000 youth

• Number of sessions ranged from 5 to 18

Eating Disorders Preventive Interventions

• Follow-up assessment ranged from three months to two years

• Mixed results on intervention impact• Three found improvement in weight concerns

• Two found no intervention effect

• None found intervention worsened symptoms

Overweight Preventive Intervention

• Robinson et al. (2003)• Goals: increase physical activity, reduce TV

• Designed for overweight prevention• Not eating disorders prevention

• 61 African-American girls, ages 8 to 10

• 12-week pilot intervention involving dance classes, educational discussion sessions

Overweight Preventive Intervention

• Results of Robinson et al. intervention:• Reduced TV viewing

• Fewer family dinners in front of TV

• Improvement in symptoms of unhealthful weight concerns

Study Question

Can an overweight prevention program reduce the risk of disordered weight

control behaviors in adolescent girls?

Planet Health Study

• Obesity prevention RCT• 10 middle schools matched, randomized to

intervention or control condition• Two school years: fall 1995 - spring 1997• Data on nutrition, physical activity, TV time, height,

weight, purging, diet pills

• Harvard School of Public Health • Drs. Gortmaker, Wiecha, Peterson, Laird• Drs. Field, Austin

Grades 6 & 7 7 & 8

Planet Health StudyEat 5 servings fruit, vegetables per day

Eat fat in moderation

Be active daily or nearly every day

2 hrs/day TV/screen time

Classroom lessons Physical education lessons

30 microunits6 fit checks

8 social studies 8 math

8 social science 8 language arts

Goals:

Overview of Planet Health Results• For girls, intervention vs. control:

• Reduced obesity prevalence (OR = 0.47)• Increased obesity remission (OR = 2.2)• Reduced TV time• TV reduction associated with reduced obesity• Increased fruit, vegetable intake• Did not increase disordered weight control

• For boys: reduced TV viewing timeGortmaker et al., Arch Ped Adol Med 1999

Measure of Disordered Weight Control Behaviors

• Purging: During the past 30 days, did you vomit or take laxatives to lose weight or to keep from gaining weight?

• Diet Pills: During the past 30 days, did you take diet pills to lose weight or to keep from gaining weight?

Statistical Analyses

• Multivariable regression analyses• Goal: Determine if Planet Health reduced girls

risk of adopting disordered weight control behavior after two years

• Excluded girls who were already purging, using diet pills at beginning of study (n=21)

Sample Characteristics at Baseline (n=480)

Control (n=226)

Intervention (n=254)

Age

11.5 yrs

11.5 yrs

Overweight

19%

22%

Ethnicity White Black Latina Other

64%

16%* 11% 9%

72% 9% 9% 9%

* Significant difference between control and intervention groups

% Adopting Disordered Weight Control Behaviors at Follow-up*

0

2

4

6

8

10

Control

Intervention%

*Girls reporting disordered weight control behaviors at baseline excluded.Austin, Field, Wiecha, Peterson, Gortmaker. Arch Ped Adol Med, 2005.

2.8%

6.2% P<0.01

Findings From Planet Health Study

Odds Ratio 95% CI

Control referenceIntervention 0.41 (0.22, 0.75)

*Model controls for ethnicityAustin, Field, Wiecha, Peterson, Gortmaker. Arch Ped Adol Med, 2005.

Girls in intervention group were less than half as likely as girls in control group to adopt disordered weight control behaviors

Preventive Proportion

• Statistic used to estimate public health importance of preventive effect due to beneficial exposure

• Interpreted as proportion of new cases of health problem that could be avoided if people received beneficial factor

Est. % of New Disordered Weight Control Cases That May Be Prevented

by Planet Health

New cases in control schools = 14/226New cases intervention schools = 7/254

Preventive proportion = 0.59

Interpretation: An estimated 59% of new cases of disordered weight control behavior among girls in control schools might have been prevented if they had received the Planet Health program

Caveats

• Small sample size, small number of cases means findings are estimates• Further research essential

• Not able to test some possible factors that may be important• Depression, self-esteem

What Have We Learned?

• Planet Health model may provide a new direction for eating disorders and obesity prevention

• May be first to protect against both disordered weight control and obesity

• Sizable estimated preventive impact• More than half of new cases might have been

prevented by intervention

What Have We Learned?

• Findings consistent with reduced weight concerns in study by Robinson et al.

• Clinicians concerned that obesity prevention efforts may worsen eating disorders• No evidence that Planet Health increased eating

disorder symptoms• But potential negative effects of other obesity

prevention efforts not yet evaluated

Planet Health Strengths

• Long-term, intensive integration of program throughout school curriculum

• Focus on healthful behavior• Nutrition, physical activity, reduced TV• No explicit focus on eating disorders, obesity

• All 6th, 7th grade students participate• Did not single out girls or overweight youth

Implications for Policy and Prevention

• Proliferation of initiatives for obesity prevention and surveillance in schools• Health promotion programs like Planet Health• “BMI report cards” and many other initiatives not

yet evaluated

• Untested initiatives raise concerns• Risk of worsening disordered eating, stigma,

burdening schools

Implications for Policy and Prevention

• Safety must be established via evaluation• Obesity prevention efforts must test effect on

disordered eating, stigma

• Feasibility, sustainability of interventions in schools requires minimizing burden• Cost-effectiveness, time efficiency

• Linking prevention research may be key to ensuring safety, feasibility, sustainability

Implications for Policy and Prevention

• Strategic Plan for NIH Obesity Research• Essential to expand support for collaboration across

both prevention fields

• New research initiatives needed to:• Establish evaluation guidelines re: disordered

eating/stigma for obesity prevention programs• Identify protective aspects of Planet Health• Test novel strategies for integrating obesity/eating

disorders prevention research

Acknowledgments

We would like to thank our collaborators and students and staff at participating schools.

This research was supported by the National Institutes of Child Health and Human Development (HD-30780), Maternal and Child Health Bureau, HRSA (5 T71 MC 00009-12-0), and Centers for Disease Control and Prevention (U48/CCU115807).

Contact Information for Planet Health

Harvard Prevention Research Center

Harvard School of Public Health

677 Huntington Ave.

Boston, MA 02115

(617)432-3840

www.hsph.harvard.edu/prc