Patients with a body mass index (BMI) > , < Body mass index (BMI) > Body mass index (BMI) is >= . BMI > Body mass index (BMI) > at study entry Patients must be eligible to undergo a ketogenic or Atkins based diet according to baseline body mass index (BMI), comorbid medical conditions, and baseline laboratory assessment Body mass index (BMI) < . Body mass index (BMI) < . Body mass index (BMI) >= at time of study enrollment BMI < at time of study enrollment Body mass index (BMI) >= BMI < at time of study enrollment Body mass index (BMI) >= mg/m^ =< days prior to registration Body mass index (BMI) > % will be considered on a case-by-case basis by the Radiation Oncology principal investigator (P.I.) Patients who are significantly below their ideal body weight (body mass index [BMI] < ) Patients with a body mass index (BMI) of or more Subjects with known severe claustrophobia or with body habitus not compatible with the bore (> lbs, body mass index [BMI] > ) may also have to be excluded Conformality index . or less cannot be achieved, or homogeneity index is > . Body mass index (BMI) > Body mass index (BMI) > % will be considered on a case-by-case basis by the radiation oncology principal investigator (PI) Body mass index (BMI) >= . Body mass index (BMI) >= BMI < Body mass index (BMI) < or > DONOR: Body mass index (BMI) =< Body mass index (BMI) of - Patients who are severely underweight (body mass index [BMI] less than ) or patients with a body surface area (BSA) < . m^ as calculated per Dubois or Mosteller Body mass index (BMI) > Body mass index ? Body mass index equal to or greater than Women of any body mass index (BMI) undergoing a laparotomy procedure for a presumed gynecologic malignancy Body mass index (BMI) >= . Body mass index of . . and body weight < pounds Patients with a body mass index (BMI) > Body mass index (BMI) < Participants must have a body mass index (BMI) of . or higher as assessed in the medical record Body mass index (BMI) =< Subjects who are underweight (defined as a body mass index [BMI] < .) Body mass index (BMI) > (morbid obesity) Body mass index (BMI) > Body mass index (BMI) > or < Body mass index (BMI) >= Body mass index (BMI) > Patients with body mass index (BMI) less than . and/or score in the severe malnourished category of the patient generated subjective global assessment (PGSGA) will be excluded Overweight (body mass index [BMI] >= ) BMI >= Patients with a body mass index (BMI) > (obese class III criteria) The subject has a body mass index (BMI) > Subjects who have a body mass index (BMI) over Body mass index (BMI) >= Body mass index (BMI) < A body mass index (BMI) >= as assessed in the medical record and have intact breasts and ovaries Body mass index under or over Body mass index (BMI) between - Overweight or obese (body mass index [BMI] of or greater) Subjects with a body mass index (BMI) of ? ; Any body mass index (BMI) Subjects must have a body mass index (BMI) of - Participants must have a body mass index (BMI) >= , defined as (weight in kilograms/[height in meters]^) Patients must have a body mass index (BMI) >= . as calculated by the formula: weight in pounds / height squared x = BMI; a BMI of:\r\n* .-. is considered normal;\r\n* .-. is considered overweight;\r\n* .+ is regarded as obese Body mass index (BMI) between - The patients has a body mass index (BMI) >, Body mass index (BMI) >= HEALTHY VOLUNTEER: Must have a body mass index (BMI) greater or equal to and less than or equal to Body mass index (BMI) > Patients exceeding the weight limitations of the scanner or are not able to enter the bore of the PET scanner due to body mass index (BMI) Patients exceeding the weight limitations of the scanner or are not able to enter the bore of the PET/CT scanner due to body mass index (BMI) Patients exceeding the weight limitations of the scanner or are not able to enter the bore of the PET/CT scanner due to body mass index (BMI) Body mass index (BMI) > (patients who may not fit on a x detector) Patients with body mass index (BMI) greater than or less than Have a body mass index (BMI) > Body mass index of or greater Patients with a lower body mass index (BMI) (BMI < ) will be excluded