PSYCHOLOGICAL EFFECTS OF SNACKS AND ALTERED MEAL FREQUENCY

Over the past two decades, substantial research has been conducted to investigate the idea that alterations in short-term nutritional intake play a role in influencing cognitive behaviour and mood. A portion of this research has examined specifically the effect of meal intake on the performance of mental tasks and subjective feelings of mood. Resul ts of this research indicate that a number of variables including the timing and nutritional composition of the meal, nutritional status, ha bitual patterns of feeding behaviour, beliefs about food, and the natu re of the mental tasks, can influence the effects of meals on cognitiv e behaviour. For example, studies have demonstrated that breakfast int ake generally is associated with an improvement in cognitive performan ce later in the morning, while Lunch intake is associated with an impa irment in mid-afternoon performance on mental tasks and more negative reports of mood. Intake of nutrients late in the afternoon appears to have a positive effect on subsequent performance on tasks involving su stained attention or memory. Although research has provided insights i nto the role of meal intake on cognitive behaviour and mood, there are a number of factors which remain to be studied. These include the int eraction of age, gender, activity level, meal composition, personality factors, stress with the effects of meals on cognitive behaviour. Add itionally, more work is needed on the time-course of short-term nutrie nt effects, and the effects of chronic changes in meal intake on behav iour.