Caloric Restriction In Sarcoma Patients Treated With Pre-Operative RT

Inclusion Criteria: * Age \>18 years * Biopsy proven soft tissue sarcoma located in the lower extremities * Patient to be treated with radiation therapy for a primary lower extremity soft tissue sarcoma or recurrent tumor after surgery, followed by surgical resection * Karnofsky Score ≥ 60% * Body Mass Index (BMI) ≥ 20 kg/m2 * Protein levels within normal limits within 45 days of enrollment * Normal kidney and liver function within 45 days of enrollment * Normal blood counts within 45 days of enrollment * Normal chemistries within 45 days of enrollment Exclusion Criteria: * Current pregnancy and breast feeding * Other cancers diagnosed within the last 5 years (in situ and/or invasive) * Diabetes mellitus * Current metformin therapy * Other conditions may exclude participants from the study (e.g. intractable nausea/emesis, allergic reaction to shake, patient decides not to have surgery, any medical condition that prevents patient from having surgery)