Can't Think Straight?

New international research shows that low-carbohydrate diets may impair cognitive performance, following a study comparing an Atkins-type diet with a reduced calorie regime.

The study, by Tufts University, Massachusetts, United States, clearly shows that dieters don’t perform as well on cognitive tests (i.e. mental function tests that deal with thinking, learning and problem solving) when carbohydrates are restricted. With reduced cognitive function, people are likely to find it difficult to concentrate, reason and problem solve, all of which can lead to poor judgement and poor decisions.

Trish Griffiths, Accredited Practising Dietitian and Executive Manager of Go Grains Health & Nutrition comments, one of the most popular diet myths of recent times is that grain-based foods such as bread, rice and pasta, and the carbohydrates they contain, provide excess energy to the body and are therefore fattening. Scientific evidence has found the complete opposite is true, that a regular intake of wholegrain foods is linked with healthy weight management. Those most successful at maintaining weight loss follow a low fat, high carbohydrate diet.

Ms Griffiths continues, the overwhelming evidence for the benefit of grain-based foods in the diet, coupled with this latest research, dispels the myth that a low carb diet is an easy option for quick results.

The brain needs glucose for energy (produced from the breakdown of carbohydrates) and diets low in carbohydrates were found to be detrimental to learning, memory, thinking and overall mood. The research suggests that restricting carbohydrates reduces the amount of energy available to the brain, thereby adversely affecting our cognitive ability.

The research findings also show that cognitive impairment improved when carbohydrates were included in meals, with data suggesting that diets can affect more than just weight.

The lower GI values of diets high in most wholegrain foods and legumes is also an important factor in weight control, as they provide a slow and sustained release of energy creating a feeling of fullness.

There is no quick fix solution to weight loss. The best way to lose weight is to eat less and be more physically active. It is also important to remember that in addition to helping to maintain a healthy body weight, grain-based foods are an excellent source of carbohydrate plus dietary fibre and protein, and are a good source of many B-group vitamins, vitamin E, and a number of minerals especially iron, zinc, magnesium and phosphorous, Ms Griffiths said.

Go Grains Health & Nutrition encourages all Australians (aged 4 years and over) to enjoy four or more daily serves of grain-based foods (preferably wholegrain) as part of a healthy, balanced diet, and make physical activity a regular part of daily life.

To find out more about the benefits of grain-based foods and health, visit the Go Grains website at or call the Go Grains 4+ Info Line: 1300 GRAINS (1300 472 467).

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