Recent research has shown that both negative life events and breakfast cereal consumption are associated with the incidence and severity of subjective symptoms of upper respiratory tract illnesses (URTIs) Two studies were conducted to examine whether objective markers of illness were also associated with stress and breakfast cereal consumption. The results from the first study showed that regular breakfast cereal consumption was associated with lower sub-lingual temperatures in volunteers with URTIs. Stress had no effect on temperature. In the second study nasal secretion weight was lower in regular breakfast cereal consumers but was not influenced by stress. These studies suggest that breakfast cereal consumption is associated with reduced illness severity and that this does not reflect stress levels. Further research is now required to determine whether such results are directly due to cereal consumption or reflect correlated attributes, such as other aspects of the diet.