The idea that sugar feeds the tumor cells is relayed by some health professionals and media alike. Patients may be torn between what they read in the media and their food preferences during and after treatment. With this survey, we aim at understanding the perception and overall consumption patterns of sugar in cancer patients together with possible physiological and psychological triggers. We decided not to include quantitative nutritional measures of the sugar consumption. The survey was distributed in a hospital setting and through a cancer support online network. Results have shown that opinion on sugar was globally "average". However, there were differences depending on sex and age. Half of the patients declared having a decreased consumption of sugar and sweet products while 26% declared an increased consumption. When looking at psychological triggers to consumption, the weight of fatigue and worry increased after cancer diagnosis compared to before. Environmental triggers such as mixed messages from health professionals or the media need to be further investigated. In line with ESPEN guidelines, we advise to maintain moderate sugar intake as part of a healthy diet to prevent malnutrition as a first line of defense against cancer-associated morbidity and mortality.