No. Cancer cells can use sugar for energy, but they also use protein and fat. In this sense, sugar, which is a type of carbohydrate, does not specifically feed cancer any more than other nutrients.
Research does not link moderate amounts of dietary sugar to the development or growth of cancer in people. A 2019 comprehensive review paper, published in European Journal of Clinical Nutrition, found no solid evidence of a connection between dietary sugar and cancer risk.
However, there is good evidence that malnutrition can make it harder for your body to recover from chemotherapy, surgery, radiation therapy and other medical interventions.
Eat small, frequent meals and snacks with plenty of protein to support good nutrition before, during and after mesothelioma treatment. Add carbohydrates and healthy fats for energy.