A low-carbohydrate/high-fat diet and a high-carbohydrate/low-fat diet both improve weight loss, enhance mood, and speed thinking, a study shows, but the low-carb diet may offer less benefit in terms of the rate of cognitive processing.
"In overweight and obese patients, following an energy-restricted dietary plan for weight loss is associated with improvements in mood, regardless of macronutrient composition," Dr Grant D. Brinkworth said.
Moreover, while both a high- and low-carbohydrate diets seem to boost the speed of cognitive processing, "the interesting result was that compared to the high-carbohydrate diet, subjects consuming the low-carbohydrate diet had a smaller improvement", Brinkworth noted.
Brinkworth, of the Commonwealth Scientific and Industrial Research Organisation-Human Nutrition, in Adelaide, Australia and colleagues compared mood and cognitive function in overweight or obese, but otherwise healthy, men and women who were between 24 to 64 years old.
8-week study
Over 8 weeks, participants followed one of two diets of similar caloric and macronutrient content, the researchers report in the American Journal of Clinical Nutrition.
The low-carbohydrate diet contained 35 per cent total protein, 61 per cent total fat (20 per cent saturated fat) and 4 per cent total carbohydrate. The high-carbohydrate diet consisted of 24 per cent total protein, 30 per cent total fat (less than 8 per cent from saturated fat), and 46 per cent total carbohydrate.
The researchers found no changes in mood among the 93 participants consuming either the low- or high-carbohydrate diet for the study duration. They did find, however, a small between-group difference, favouring the high-carb dieters, in the speed in which participants performed intelligence and reasoning tests.
The findings suggest, Brinkworth noted, that "very low carbohydrate diets may offer less benefit than a high carbohydrate diet for improving cognitive function".
