Examining the Effects of Juice Fasting

Up to 30 participants will be enrolled in the study and will be randomized into one of the
three arms: the "juice fasting" arm, the "juice plus ad hoc" arm, and the "caloric
restriction" arm. Participants will come into the lab for an initial visit, during which they
will complete questionnaires on their usual diet and demographics and will be informed about
their assignment to one of the three arms.

In all three arms, the three-day diet intervention will be preceded and followed by three
days of self-conducted elimination diet. The pre-intervention diet will encourage
participants to eat a healthy, light diet for three days (basic instructions: eat only fresh
raw or cooked fruits and vegetables (preferably organic), whole grains and eggs; drink 8
glasses of water a day; avoid or eliminate alcohol, caffeine, sugar, processed foods, dairy,
red meat, and gluten). The post- intervention diet will instruct participants to gradually
return to eating solid foods, and limit strenuous exercise (basic instructions: follow a diet
similar to the pre-intervention elimination diet; day 1 after the intervention: eat fruits &
green vegetables, and drink 8 glasses of water; day 2 add in: nuts, gluten-free grains like
whole oats, quinoa, or brown rice; day 3 add in: organic meats, fish, & gluten-containing
grains).

Biological samples and self-reported outcomes will be collected at four time points: baseline
(prior to the first elimination diet period), pre-intervention (after the elimination diet
and before the three-day intervention), post-intervention (after the intervention), and
14-day post- intervention. At each time point, participants will complete questionnaire on
quality of life (PROMIS - Global Health Scale, which is an NIH measure on an individual's'
overall physical and psychological well-being; see appendix) and collect their stool samples.
Participants will be provided self-administered tool kits and be taught how to collect the
stool sample at their first lab visit. At each of the four time points, the research
assistant will coordinate the collection of cheek swabs, saliva samples, and blood spot
samples. Biometrics will also be collected at each time point (weight, waist circumference,
and blood pressure).

Over the course of the study, participants will be instructed to keep a diet diary days one
through nine to record their daily dietary intake. During the intervention period, the
research team will also contact the participants for daily check-ins. Participants will not
need to record diet data for the remaining 11 days of the post-intervention period.

At the conclusion of the study, participants will bring back the final biological samples
(stool wipe and saliva), provide the set of samples, and be debriefed about the purposes of
the study.

The biological samples collected will then be processed and assayed for microbiome,
methylation, inflammatory markers, and glycemic markers.

Inclusion Criteria:

- Subjects considered as healthy by the investigator based on medical history and
completion of the screening questionnaire.

- Subjects who, according to the investigator, can and will comply with the requirements
of the protocol and are available for all scheduled visits at the investigational
site.

- Healthy male or female aged between 18 and 35 (included) years

- 18.5 ≤BMI ≤ 30 kg/m²

- Ability to give their informed consent in writing

Exclusion Criteria:

- Documented history of previous cardiovascular disease, including coronary heart
disease (CHD) (angina, myocardial infarction, coronary revascularization procedures or
existence of abnormal Q waves in the electrocardiogram (EKG)), stroke, syncope, and
clinical peripheral artery disease with symptoms of intermittent claudication.

- Severe medical condition that may impair the ability of the person to participate in a
nutrition intervention study (e.g. digestive disease with fat intolerance, advanced
malignancy, or major neurological, psychiatric or endocrine disease including
diabetes).

- Daily use of any prescription or non-prescription medication that has a high
likelihood of impacting systemic inflammation (e.g. non-steroidal anti inflammatories
or steroids), blood sugar control (e.g. medication for diabetes) or the human
microbiome (e.g. antibiotics).

- Any other medical condition thought to limit survival to less than 1 year.

- Known immunodeficiency disorder

- Illegal drug use or chronic alcoholism or total daily alcohol intake >80 g/d.

- Difficulties or major inconvenience to change dietary habits

- Impossibility to follow an elimination or juice fast diet, for religious reasons or
due to the presence of disorders of chewing or swallowing (e.g., difficulties to
consume nuts)

- A low predicted likelihood to change dietary habits according to the Prochaska and
DiClemente stages of change model (Nigg, 1999).

- History of food allergy with hypersensitivity to any of the components of the juice or
diet

- Patients with an acute infection or inflammation (e.g., pneumonia) are allowed to
participate in the study 3 months after the resolution of their condition.

- Dietary restrictions due to medical (including allergies), religious, or other
concerns

- Any diagnosis of allergic rhinitis, eczema, asthma, or inflammatory bowel disease
(e.g. ulcerative colitis or Crohn's) from a health professional