Inclusion Criteria:

Cancer groups (for aims 1 and 2)

1. Recently diagnosed (up to 4 weeks prior to treatment for cancer) with stage I, II
or III invasive breast cancer

2. Undergoing mastectomy

3. Age greater than 30 years

4. Ability to sign informed consent

5. Good performance status defined by ECOG scale 0,1 or 2 (see CRF performance status)

Control group (for aim 1)

1. Age greater than 30 years

2. Undergoing prophylactic mastectomy

3. Ability to sign informed consent

4. Good performance status defined by ECOG scale 0,1 or 2 (see CRF performance status)

Exclusion Criteria:

All groups (aim 1 and 2)

1. Body weight loss of greater than 10% in the past 3 months

2. Previous anti-cancer therapy (e.g. chemotherapy or radiotherapy) or surgery less than
4 weeks prior to the experiment

3. Diagnosed diabetes type I or II

4. Untreated metabolic diseases including liver or renal disease

5. Any documented autoimmune disease

6. Use of corticosteroids, beta-antagonists or nitrovasodilators

7. Use of supplements enriched with amino acids

8. Presence of acute illness or metabolically unstable chronic illness

9. Unstable heart disease requiring therapy or recent myocardial infarction (less than 1
year)

10. Current alcohol or drug abuse (ETOH more than 2 servings per day)

11. Allergy/intolerance to any of the ingredients of the study products

12. Any other condition deemed by the PI and the study physician as exclusion or that
interferes with proper conduct of the study/ safety of the patient.