I can barely eat during chemo. How do I keep my strength up?

Thank you for caring for your mother so attentively — what you describe (metallic taste, early fullness, weight loss) is very common during chemotherapy, and there are practical things that help.

1) Shift from three meals to 6–8 small "snack-meals" a day. Early fullness is easier to work around than to fight. 2) Prioritize protein first in each mini-meal: eggs, yogurt, soft fish, tofu, or a nutrition shake. 3) For metallic taste: cold or room-temperature foods usually taste less metallic than hot ones; plastic or bamboo utensils instead of metal can help; lemon or vinegar seasoning masks the taste for many patients. 4) A 4kg loss in a month deserves attention from her own team — please tell her oncologist at the next visit, and ask for an oncology dietitian referral. If she develops mouth sores, fever, or cannot keep fluids down, contact her team promptly rather than waiting.

This answer is general medical information, not a diagnosis or a prescription. Her own care team, who know her full history, should guide any changes.