PurposeThere are several reasons to report days as being unusual with regard to dietary intake, including special occasions and celebrations. For breast cancer patients during the 12 month post-surgery period, unusual days may also include days that are affected by being a cancer patient. The aim of this study was to study dietary intake on “normal” and “unusual” days, and to study what is reported in “free text fields” of a food diary.MethodsWomen (n = 456), mean age 55.5 years newly diagnosed with invasive breast cancer (stage I/II) were included in this clinical study. “Normal” and “unusual” days in general, over time and during the week and weekends were studied using repeated administration of a 7-day pre-coded food diary.ResultsThe breast cancer patients reported 26% of all days as unusual. The intake of energy, most nutrients, especially alcohol and sugar, red and processed meat, and sweets, cakes, and snacks was 5–126% higher, whereas intake of fiber, fruit and berries, vegetables, and dairy products was 7–17% lower on unusual than on normal days (P < 0.001). The same pattern was seen for normal/unusual days during the weekdays, weekends and over time. Finally, 99% of the breast cancer patients used the free text fields to report additional intake with a mean energy of 1.1 MJ/day.ConclusionFor breast cancer patients during the 12-month post-surgery period, unusual days are important drivers of total intake, especially for alcohol. The free text fields in the pre-coded food diary contributed substantially to the total intake.