Major weight loss and taste changes are well documented in patients with hematological cancer during chemotherapy. We have previously documented, that such patients have preferences for much umami, a little sweet, sour and salt, and no bitter. We wanted to convert these results into real diets. Patients participated in two sensory pilot studies (n = 10), where dishes were tested for preferences before and after chemotherapy. From these results, four dishes were selected and tested on 32 patients in 30 days in a cross-over design. The diets resulted in a beneficial and statistically significant difference in weight development (p = 0.0008), with 1.2 ± 1.9 kg (+2%) in the intervention period and -2.8 ± 5.2 kg (-4%) in the control period. This difference persisted after sensitivity analysis (±10%) P = 0.005. However, the nutritional intake was still low in both periods, and the treatment with cytarabine turned out to be a major confounder as dosage was significantly higher in the control period.