The start of every new year brings a flurry of snow and resolutions. Here at Tufts, new commitments to physical wellness send students to Gantcher in droves and lead many to wonder how to diet on a Tufts meal plan.
New research from the Tufts psychology department, however, suggests that the low-carbohydrate diets popularized by dieting regimes, like the Atkins diet, the Zone diet and the South Beach diet, affect the mind as well as the body.
Professor of Psychology Holly Taylor recently co-authored a study with Professor of Psychology Robin Kanarek, examining the effects of low-carbohydrate dieting on cognitive functioning.
After recruiting women for the study who were already planning to begin a diet, the researchers allowed the women to choose between a diet low in carbohydrates and a nutritionally balanced diet approved by the American Dietetic Association (ADA), a worldwide organization of food and nutrition professionals. The researchers tested the women's cognitive functioning after 48 hours of dieting and then once a week for the next three weeks.
Most low-carbohydrate diets, according to Taylor, cut out carbohydrates entirely for the first week of dieting, which was enough time for noticeable cognitive changes to occur.
"At the one-week point, short-term and spatial memory of the women on the low-carb diets was worse than that of the women on the balanced diet," Taylor said.
But these results were not entirely surprising. "The primary fuel of the brain is glucose, which the body gets when it breaks down carbohydrates," Taylor explained. So to stop eating carbohydrates is to deprive the brain of fuel it needs for short-term and spatial memory.
The study highlights how the effects of unbalanced dieting are not limited to the physical, according to Taylor. "The body needs all kinds of different nutrients," she said, "People don't think about how … [their] diet can affect [their] thinking processes as well."
Taylor advised dieters to anticipate these mental effects.
"The recommendation would be to watch out in the first week when a lot of these diets ask people to go on no-carb diets, [during which] you're going to see effects on the cognitive functions," she said.
Cutting down on carbs, while not eliminating them entirely, may be beneficial, though. The study found that low-carbohydrate dieting can have positive mental effects as well.
"We also saw that women on low-carb diets have better vigilance attention — being able to stay on task for longer periods of time," Taylor said.
And cognitive functions returned to a normal level when just five to eight grams of carbohydrates per day were reintroduced into the women's diets, which is far less than what the ADA recommends individuals consume.
This study is part of a long and renowned tradition of health and nutrition research at Tufts. "We have the Friedman School of Nutrition downtown; [Kanarek] is affiliated with that," she explained. "There is a lot of first-class diet and nutrition study going on here, and Tufts is known for that."
Taylor plans to work with Kanarek on future studies examining dieting and cognition. "We have a whole series of food- and diet-related studies, looking at breakfast consumption, chronic protein consumption and snacks," she said.
