The purpose of this research is to investigate the effects of a PB no- added-fat and the AHA and MED in obese (BMI >95%) children ages 9-18 with hypercholesterolemia (>169 mg/dl) and a parent or guardian. Eligible patients will be identified by utilizing the Pediatric Obesity Registry. When possible, in-person discussions or phone calls with their primary or tertiary care physicians will introduce eligible patients and their parents to the study. All eligible patients and parents will receive letters describing the study and requesting their participation. Subjects can choose not to participate in the study, and their health care will not be affected in any way. Subjects not participating will be asked if they are willing to answer a brief questionnaire about why they chose not to participate. The proposed study will be carried out for a total of 52 weeks. The investigators expect to recruit a total of 180 participants (30 children and 30 parents/guardians in each of the three groups). Each child and parent/guardian pair will be randomly assigned to either PB no-added-fat, AHA or MED.

Background: There is a need to have effective lifestyle modifications that target the growing group of obese children with dyslipidemia. The beneficial health effects of plant-based (PB) diets in adults are known. Studies have suggested that a low-fat vegan diet (no animal products) may promote weight loss, lower body mass index (BMI), and improve lipoprotein profiles and insulin sensitivity and possibly prevent cardiovascular disease (CVD).1-5 Those who follow a vegetarian diet(no animal products except for dairy and/or eggs) typically have lower cholesterol levels and a lower risk for heart disease than non-vegetarians.6-8 Additionally, vegetarian diets have been shown to not only prevent but reverse heart disease in adults.9-11 The three major diets emphasized in the 2015 United States Dietary Guidelines are a Plant-based Diet (PB), and the American Heart Association-like Diet (AHA) and Mediterranean Diet (MED).(11) Similar to the PB, the AHA diet encourage fruits, vegetables, whole grains, and low sodium intake but permits non-whole grains, low-fat dairy, selected plant oils, and lean meat and fish in moderation. The MED, is similar to AHA with more emphasis on fish and extra virgin olive oil and/or nuts).

Study Aims: The primary aim of this study is to determine whether a PB and/or AHA and/or MED diets significantly change anthropometric measurements and/or biomarkers of CVD risk after a 4 and 52-week intervention in obese children with hypercholesterolemia ages 9-18 years and one of their parents. The investigators also aim to prospectively determine for the first time in children and adults if there are significant outcome differences between the three diets highlighted in the 2015 U.S. Dietary Guidelines.

Protocol Summary The purpose of this research is to investigate the effects of a PB no- added-fat and the AHA and MED in obese (BMI >95%) children ages 9-18 with hypercholesterolemia (>169 mg/dl) and a parent or guardian. Eligible patients will be identified by utilizing the Pediatric Obesity Registry. When possible, in-person discussions or phone calls with their primary or tertiary care physicians will introduce eligible patients and their parents to the study. All eligible patients and parents will receive letters describing the study and requesting their participation. Subjects can choose not to participate in the study, and their health care will not be affected in any way. Subjects not participating will be asked if they are willing to answer a brief questionnaire about why they chose not to participate. The proposed study will be carried out for a total of 52 weeks. The investigators expect to recruit a total of 180 participants (30 children and 30 parents/guardians in each of the three groups). Each child and parent/guardian pair will be randomly assigned to either PB no-added-fat, AHA or MED.

Procedures of the study:

Eligible patients and parent/guardian pairs who are interested in participating in the study will have an initial phone call with the study team to answer any questions regarding the study. Informed consent, or assent for children under age 18, will then be obtained by study team investigators face-to-face with the parent/guardian and child pairs prior to the start of the study at a mutually convenient time and place at Cleveland Clinic Regional and Main Campus sites. Patient and parent/guardian pairs will be randomized to one of the three diets at the first study visit.

Throughout the 52 week diet study, participants will be asked to attend group sessions held on Saturdays during weeks 0, 1, 2, 3, 4, and 52 to learn about their assigned diets and receive support for their efforts. There will Saturday support sessions during weeks 6, 10, 16, 24, 34, and 46 and support phone calls every 2 weeks.

The participants will also provide 24 hour dietary recalls of 2 weekdays and 1 weekend day on three time points: before the first study visit, between weeks 2 and 4, and then between weeks 48 and 52.

Participants will have fasting blood tests to assess biomarkers of cardiovascular risk and anthropometric measurements will be performed weeks 0, 4, and 52. Stool and urine specimens will be obtained for possible future testing for microbiome, genomic data and markers of cardiovascular risk at weeks 0, 4, and 52.

Inclusion Criteria:

• children ages 9-18
• obese (BMI >95%)
• hypercholesterolemia (>169 mg/dl)

Exclusion Criteria:

• pregnant women