Weight loss improves memory and alters brain activity in overweight women

June 17, 2013

Memory improves in older, overweight women after they lose weight by dieting, and their brain activity actually changes in the regions of the brain that are important for memory tasks, a new study finds. The results were presented today at The Endocrine Society's 95th Annual Meeting in San Francisco.

"Our findings suggest that obesity-associated impairments in memory function are reversible, adding incentive for weight loss," said lead author Andreas Pettersson, MD, a PhD student at Umea University, Umea, Sweden.

Previous research has shown that obese people have impaired episodic memory, the memory of events that happen throughout one's life.

Pettersson and co-workers performed their study to determine whether weight loss would improve memory and whether improved memory correlated with changes in relevant . A special type of brain imaging called (functional MRI) allowed them to see brain activity while the subjects performed a memory test.

The researchers randomly assigned 20 overweight, postmenopausal women (average age, 61) to one of two healthy for six months. Nine women used the Paleolithic diet, also called the Caveman diet, which was composed of 30 percent protein; 30 percent carbohydrates, or "carbs"; and 40 percent unsaturated fats. The other 11 women followed the Nordic Nutrition Recommendations of a diet containing 15 percent protein, 55 percent carbs and 30 percent fats.

Before and after the diet, the investigators measured the women's (BMI, a measure of weight and height) and body fat composition. They also tested the subjects' episodic memory by instructing them to memorize unknown pairs of faces and names presented on a screen during functional MRI. The name for this process of creating new memory is "encoding." Later, the women again saw the facial images along with three letters. Their task, during functional MRI, was to indicate the correct letter that corresponded to the first letter of the name linked to the face.

Because the two dietary groups did not differ in body measurements and functional MRI data, their data were combined and analyzed as one group. The group's average BMI decreased from 32.1 before the diet to 29.2 (below the cutoff for obesity) after six months of dieting, and their average weight dropped from 188.9 pounds (85 kilograms) to 171.3 pounds (77.1 kilograms), the authors reported. This study was part of a larger, diet-focused study funded by the Swedish Research Council and the Swedish Heart-Lung Foundation.

Memory performance improved after weight loss, and Pettersson said the brain-activity pattern during memory testing reflected this improvement. After weight loss, brain activity reportedly increased during encoding in the brain regions that are important for identification and matching of faces. In addition, brain activity decreased after weight loss in the regions that are associated with retrieval of episodic memories, which Pettersson said indicates more efficient retrieval.

"The altered brain activity after suggests that the brain becomes more active while storing new memories and therefore needs fewer brain resources to recollect stored information," he said.

Explore further: Multivitamin lifts brain activity, memory

Related Stories

Multivitamin lifts brain activity, memory

November 2, 2012

(Medical Xpress)—A daily multivitamin supplement may improve brain efficiency in older women, according to new research from Swinburne University of Technology.

'Eating more protein' strategy helps women lose weight

May 11, 2013

(HealthDay)—Women who report "eating more protein" as a weight loss strategy achieve weight loss over two years, according to a study published in the May issue of the Journal of Nutrition Education and Behavior.

Adolescents' high-fat diet impairs memory and learning

June 17, 2013

A high-fat diet in adolescence appears to have long-lasting effects on learning and memory during adulthood, a new study in mice finds. The results were presented Saturday at The Endocrine Society's 95th Annual Meeting in ...

Recommended for you

New insights on how cocaine changes the brain

November 25, 2015

The burst of energy and hyperactivity that comes with a cocaine high is a rather accurate reflection of what's going on in the brain of its users, finds a study published November 25 in Cell Reports. Through experiments conducted ...

Can physical exercise enhance long-term memory?

November 25, 2015

Exercise can enhance the development of new brain cells in the adult brain, a process called adult neurogenesis. These newborn brain cells play an important role in learning and memory. A new study has determined that mice ...

Umbilical cells help eye's neurons connect

November 24, 2015

Cells isolated from human umbilical cord tissue have been shown to produce molecules that help retinal neurons from the eyes of rats grow, connect and survive, according to Duke University researchers working with Janssen ...

Brain connections predict how well you can pay attention

November 24, 2015

During a 1959 television appearance, Jack Kerouac was asked how long it took him to write his novel On The Road. His response – three weeks – amazed the interviewer and ignited an enduring myth that the book was composed ...

No cable spaghetti in the brain

November 24, 2015

Our brain is a mysterious machine. Billions of nerve cells are connected such that they store information as efficiently as books are stored in a well-organized library. To this date, many details remain unclear, for instance ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.