Patients with uncontrolled hypertension are ineligible; uncontrolled hypertension is defined as follows:\r\n* Patients aged =< years: greater than th percentile systolic and diastolic blood pressure based on age and height which is not controlled by one anti-hypertensive medication\r\n* Patients aged > years: systolic blood pressure >= mmHg and/or diastolic blood pressure >= mmHg that is not controlled by one anti-hypertensive medication Patients who are currently receiving more than one anti-hypertensive medication (grade ) or whose blood pressure is not controlled are not eligible for study enrollment Poorly controlled hypertension. During screening ?/ of readings must be < /, regardless of whether on a regimen of anti-hypertensive therapy or not. Patients who are currently receiving more than one anti-hypertensive medication (Grade ) or whose blood pressure is not well controlled are not eligible for study enrollment. Patients who are receiving anti-hypertensive medications for control of blood pressure at the time of enrollment are not eligible for this trial Presence of any of the following conditions, which are risk factors for RVO: Uncontrolled glaucoma with intraocular pressure > millimetres of mercury (mm Hg); Serum cholesterol >/=Grade ; Hypertriglyceridemia >/=Grade ; Hyperglycemia (fasting) >/=Grade ; Grade >/= uncontrolled hypertension (participants with a history of hypertension controlled with anti-hypertensive medication to Grade systolic or > diastolic mmHg) with anti-hypertensive therapy within days of first dose of therapy Patients will be excluded from study participation if they currently are known to have any of the following risk factors for RVO: a. Glaucoma with intraocular pressure >= mmHg b. Grade >= serum cholesterol c. Grade >= hypertriglyceridemia d. Grade >= or symptomatic hyperglycemia (fasting) e. Grade >= uncontrolled hypertension (patients with a history of hypertension controlled with anti-hypertensive medication to grade =< are eligible Hypertension requiring or more anti-hypertensive medications to control Have uncontrolled hypertension; subjects with a history of hypertension are permitted in the study provided their blood pressure is controlled by anti-hypertensive therapy PHASE II COLORECTAL CANCER COHORT (MEDI+C ONLY):\r\nAdequately controlled blood pressure (SBP < mm Hg and DBP < mmHg) on a maximum of three anti-hypertensive medications Patients must have controlled blood pressure with a systolic blood pressure < mmHg and diastolic < mmHg (for patients with an elevated initial blood pressure (BP) reading [hypertensive range], a repeat measurement at least minutes later should be performed, and the two readings should be averaged to obtain a BP reading); any hypertensive at-home blood pressure reading will be confirmed in clinic; patients on anti-hypertensive medications are eligible, if blood pressure is controlled; study drug dosing will be interrupted for any reading >= / Inadequately controlled hypertension (defined as systolic blood pressure > mmHg and/or diastolic blood pressure > mmHg) despite antihypertensive medication, or prior history of hypertensive crisis or hypertensive encephalopathy A requirement for a calcium channel blocker for blood pressure control that cannot be switched to an antihypertensive with an alternative mechanism of action; permitted anti-hypertensive medications include: chlorothiazide, hydrochlorothiazide, atenolol, nadolol, enalapril, lisinopril, eprosartan, and irbesartan Patients who are receiving anti-hypertensive medications for control of blood pressure at the time of enrollment are not eligible for this trial Hypertensive patients with uncontrolled blood pressure. Uncontrolled symptomatic hypertension that cannot be controlled with anti-hypertensive agents History of hypertension not well-controlled (>= /) even though on a regimen of anti-hypertensive therapy Controlled blood pressure defined as a systolic blood pressure =< mmHg and diastolic blood pressure =< mmHg on no more than three anti-hypertensive agents; drug formulations containing two or more anti-hypertensive agents will be counted based on the number of active agents in each formulation No patients with inadequately controlled hypertension (defined as a blood pressure of >= mmHg systolic and/or >= mmHg diastolic), or any prior history of hypertensive crisis or hypertensive encephalopathy Controlled blood pressure (systolic blood pressure < and diastolic blood pressure < ) on no more than three anti-hypertensive agents; drug formulations containing two or more anti-hypertensive agents will be counted based on the number of active agents in each formulation Patients with a history of hypertension should be well controlled (< / mmHg) on a regimen of anti-hypertensive therapy Inadequately controlled hypertension (systolic blood pressure of > mmHg or diastolic pressure > mmHg on anti-hypertensive medications); Note: history of hypertensive crisis or hypertensive encephalopathy not allowed Patients with a history of hypertension must be well-controlled (< /) on a regimen of anti-hypertensive therapy Patients with inadequately controlled hypertension (defined as a blood pressure of > mmHg systolic and/or > mmHg diastolic on medication), or any prior history of hypertensive crisis or hypertensive encephalopathy Uncontrolled hypertension (home blood pressure readings are permitted) or prior history of hypertensive crisis or hypertensive encephalopathy; however, treatment of hypertension with medications is permitted Patients receiving anti-hypertensive medicines must be on a stable regimen for at least month History of hypertensive or diabetic retinopathy Patients who have persistently elevated systolic blood pressures (BPs) >= or diastolic BPs >= need to have their systolic or diastolic BP controlled with anti-hypertensive agents for at least days prior to the initiation of cell therapy; patients already on anti-hypertensive agents will have their medicine adjusted based on the clinical judgment of the patient care team Patients with a history of hypertension must be well-controlled (< systolic/< diastolic) on a stable regimen of anti-hypertensive therapy Recent initiation (within -months) of anti-hypertensive medication (individuals on stable therapy may be enrolled) Hypertensive medication should be initiated or increased for optimal blood pressure control according to standard public health guidelines prior to starting the ketogenic diet Hypertensive medication should be initiated or increased for optimal blood pressure control according to standard public health guidelines prior to starting the ketogenic diet Inadequately controlled hypertension (defined as systolic blood pressure >= and/or diastolic blood pressure >= mmHg on antihypertensive medications), any prior history of hypertensive crisis or hypertensive encephalopathy, and history of myocardial infarction or unstable angina within months prior to study enrollment Poorly controlled hypertension (defined as requiring changes in any hypertensive regimen within week of study entry) or patients diagnosed with hypertension based on repeat blood pressure measurements of > / mmHg at screening Blood pressure <=Grade (hypertensive participants are permitted if their blood pressure is controlled to <=Grade by hypertensive medications. Blood pressure ?Grade (hypertensive participants are permitted if their blood pressure is controlled to ? Grade by hypertensive medications and glycosylated hemoglobin is ?.%). History of hypertension that is not well-controlled (>= /) on anti-hypertensive therapy Uncontrolled hypertension (defined as blood pressure in adults > /)\r\n* Patients on anti-hypertensive medications are eligible if blood pressure is controlled Hypertensive-level readings over three weeks, with at least two of three elevated blood pressure (BP) readings (systolic >= and/or diastolic >= ); OR one hypertensive crisis reading (systolic >= and/or diastolic >= ) (eligible for the study without having to return for second or third readings) OR have a known diagnosis of hypertension and have elevated values at one reading (eligible for the study without having to return for second or third readings) Normotensive or controlled blood pressure (< /) on a single anti-hypertensive medication Blood pressure <= Grade (hypertensive participants are permitted if their blood pressure is controlled to <= Grade by hypotensive medications and glycosylated HbAC <= .%).