This open-label study involves evaluating tolerance and acceptability of the test ONS in 16 adult participants who are already taking an ONS. Following a 2-day baseline data collection on their current ONS, patients switch to the test ONS, which is taken for a further 8 consecutive days. Patients revert to their current ONS at the end of the study. Patients act as their own controls and thus all patients are allocated the same intervention.