What percentage of unintentional weight loss is considered a red flag during active cancer treatment?

• A. 2% or more
• B. 1% or more
• C. 5% or more
• D. 0%

Answer: (A)

During active cancer treatment, unintentional weight loss is watched closely because it can signal developing malnutrition and affect treatment tolerance. A small but ongoing loss of two percent or more is treated as a red flag, triggering a nutrition assessment and possible intervention to prevent further decline and support treatment effectiveness. A one percent loss is generally not enough to raise concern, while five percent or more indicates more substantial malnutrition risk but the threshold for a red flag in this context is two percent. Zero percent means no weight change, which isn’t a red flag.