A lower rather than a higher glycemic load (GL) meal has been shown to benefit cognition and mood, however, the data in older adults and those most prone to cognitive dysfunction, is limited and conflicting. One explanation is that the GL of a meal may interact with a person's pre-existing glucose tolerance (GT).

As older adults have a higher incidence of glucose tolerance and are more likely to experience memory problems the present study considers the interaction between the GL of meal in those with better or poorer GT.

The population studied will not have a history of diabetes or dementia. A battery of cognitive tests will be administered after meals sweetened with one of three sugars known to vary in the rate that they release glucose into the blood stream.

On day one subjects will take an oral glucose tolerance test and will then be divided into four groups depending on their glucose tolerance (how long values remain raised) and the tendency for values to subsequently fall to low values.

On a second occasion 155 healthy older adults, aged 45-80 years, will be randomly assigned to receive either a glucose, sucrose or isomaltulose based meal. All meals are matched on macronutrient composition and differ only in glycemic load. Cognitive performance and mood will be assessed 30, 105 and 180 minutes after breakfast. Measures of memory, attention, reaction times and mood will be taken.

The response to the three meals will be contrasted in those with different glucose profiles on day one

Inclusion Criteria:

• Healthy adults of 45 to 80 years

Exclusion Criteria:

• Type 1 or type 2 diabetes
• Dementia
• Liver disease
• Gastro-intestinal problems