Think AHEAD (A Healthy Eating And Drinking) Study

This is a 6-month randomized controlled trial. After the initial baseline screening and
assessments, 60 overweight adolescents will be randomly assigned (30 subjects per group) to
a standard weight-reducing diet with the advice to consume 8 cups of water per day
(experimental group) or the same standard weight-reducing diet without additional advice
(control group). The interventions will consist of nutrition education and behavioral
counseling by a registered dietitian, during individual sessions and telephone calls. Mobile
text messaging will be used to reinforce information presented at the individual sessions
and thereby foster adherence to dietary advice. Diet prescriptions will differ only in
regard to the specificity of recommendations regarding water consumption and physical
activity recommendations will not differ between groups. The frequency and content of text
messages will be consistent between the experimental and control groups, with the exception
that the experimental group will receive an additional phrase with each message to encourage
the "8 x8" water recommendation.

A registered dietitian will communicate with each participant one time per month, either
during an individual session or by telephone. Individual sessions will include nutrition
classes, taste testing, hands-on activities, and opportunities for questions and answers.
Text messages will be sent on a daily basis.

Study outcomes will be assessed at baseline and at regular intervals throughout the 6 months
of the study.

ANALYSIS PLAN:

The blinding of the randomization will be broken on or after July 28, 2014 and the data will
be analyzed according to the following plan. All analyses will follow the intention-to-treat
principle, attributing each subject to his or her assigned diet regardless of compliance.
Baseline characteristics will be compared between the diet groups using the Fisher exact
test for categorical variables and t-test for continuous variables. The 6-month change from
baseline in the primary and secondary outcomes will be compared between groups using a
general linear model, adjusting for baseline covariates that are potentially correlated with
the outcome. These include demographics, socioeconomic status, anthropometrics, physical
activity, and beverage consumption. We will further test covariates for potential
interaction, i.e., differential effect on outcome in the two trial arms. The null hypothesis
is that the 6-month change from baseline will not differ between diet groups.

Inclusion Criteria:

- BMI ≥ 85th percentile for sex and age according to CDC growth charts

- Access to a working telephone and cell phone

- At least one parent willing and able to participate in the intervention with the
subject

- Residing in predominately one household (no more than one weekend every two weeks in
a secondary household)

- Medical clearance from a primary care provider or treating physician to rule out any
major medical illness, disability, or disorder (e.g., liver disease, renal failure,
cancer)

Exclusion Criteria:

- Intake of more than 4 cups (250 mL per cup) of water per day

- BMI ≥ 40 kg/m2

- Currently smoking (> 1 cigarette in the past week)

- Major surgery within the previous 6 months

- Does not have a primary care provider

- Physician diagnosis of a major medical illness (e.g. diabetes)

- Previous diagnosis of an eating disorder

- Physical, mental, or cognitive handicaps that prevent participation

- Chronic use of medications that may affect study outcomes (e.g. stimulants or
diuretics)

- Another member of the family (first degree relative) or household participating in
the study

- A friend, classmate or coworker participating in the study with whom they have
contact with one or more times per week

- Girls who are pregnant, planning to become pregnant in the next 6 months, lactating,
or within 6 months postpartum