Patients with atopic dermatitis frequently blame food for worsening their eczema. Recently, a sugar-free diet has become very popular among German patients. In order to investigate whether sucrose is an aggravating factor in atopic dermatitis, we conducted a prospective study in 30 patients. Double-blind, placebo-controlled food challenges with sugar were performed during a sugar-free diet period, which was started one week prior to the first challenge. Study parameters included the SCORAD index and eosinophilic cationic protein levels, which were determined before diet, on food challenges and one day after. In 29 evaluable patients we observed no significant difference in study parameters after the verum challenge compared to the placebo challenge. From these results, we conclude that sugar is not an aggravating factor in atopic dermatitis, which contradicts the view of many patients and underlines the importance of evidence-based medicine in the guidance of patients.