Does radiation make you lose weight?
Christopher Davis
Updated on May 14, 2026
Many cancer patients lose weight unexpectedly during radiation therapy because they struggle with side effects caused from treatment.
How much weight do you lose during radiation treatment?
Weight changes during the radiotherapy were as follows: 78.7% of patients lost weight, 8.5% gained weight (0.7 −3.6 kg), and 12.8% had no weight change. Weight loss was significant (t-test two-paired, p-valueDoes radiation make you lose or gain weight?
Radiotherapy to your head and neck area can make you lose weight because you might have: a sore or dry mouth. a poor appetite.What is the most common side effect of radiation?
Early and late effects of radiation therapyThe most common early side effects are fatigue (feeling tired) and skin changes. Other early side effects usually are related to the area being treated, such as hair loss and mouth problems when radiation treatment is given to this area.