BACKGROUND: Little is known about the link between mood, food and metabolic function in Seasonal Affective Disorder (SAD). METHODS: We investigated this link in a combined glucose tolerance-alliesthesia test in eight SAD patients in winter before and after one week light therapy, and in summer. RESULTS: SAD patients exhibited faster post-glucose glycaemic and insulin responses (p textless0.05), and increased hedonic ratings of high concentrated sucrose solutions (p textless0.035) when depressed in winter than when euthymic (one week after light treatment or in summer). CONCLUSIONS: The rapid glycaemic and insulin responses to an oral glucose load may be a result of accelerated gastric emptying. LIMITATIONS: The number of studied patients was rather small and no control group was studied in parallel. CLINICAL RELEVANCE: the more rapid post-glucose glycaemia may impair glucose homeostasis in depressed SAD patients.