The obesity epidemic is not only bad for our waistlines, but it could have a significant effect on our minds, as well. “Obesity not only impacts how you look … or physical health, it also impacts your brain,” says Ranjana Mehta, an assistant professor of environmental and occupational health at the Texas A&M Health Science Center School of Public Health in College Station, Texas. The researcher, who’s received National Institute on Aging funding to study obesity’s effects on brain function in seniors, notes obesity can change the structure of the brain and cause atrophy.

ADDED POUNDS COULD CLOUD MEMORY.

A higher BMI is associated with poorer episodic memory – or difficulty recalling past events – in young adults ages 18 to 35, according to a small study published online in February in The Quarterly Journal of Experimental Psychology. The findings could suggest that “people who are overweight may experience memory slightly less vividly or in less detail,” said lead researcher Lucy Cheke, a lecturer in the department of psychology at the University of Cambridge in England, in an email. Other evidence indicates memory plays an important role in regulating what we eat, so Cheke says such slight problems may make it harder to watch what one eats and lose weight.

MIDLIFE OBESITY IS ASSOCIATED WITH A HIGHER RISK OF DEMENTIA.

In addition to the research Cheke led focused on young adults, other studies have found that being obese in one’s 40s, 50s and even early 60s is associated with a higher risk of dementia as a person ages. “Midlife obesity is linked to an increased risk of Alzheimer’s and related dementias in later life,” says Heather Snyder, senior director of medical and scientific operations at the Alzheimer’s Association. The reasons for this are not clear, but it’s known that added pounds negatively affect cardiovascular health, which plays a role in brain health.

OBESITY CAN MAKE IT HARD TO GET A GRIP.

If you’re reading this while holding a smartphone, you have your brain to thank as well as your hand for maintaining a firm grasp on your mobile device. However, research Mehta led in elderly individuals finds that obesity is associated with changes in brain activity that affect neuromuscular function, including making it harder to grasp. That could make it more difficult to open a pill bottle to take meds or grip a stair railing. “It could result in a fall if their grip is not reliable,” Mehta says, noting obese individuals’ grasping ability was further impaired under stress.

IT MAY BE HARDER – ON THE BRAIN AND BODY – TO WALK AND TALK.

Step by laborious step, it’s simple to see how extra weight can bear heavily on joints, making ambulation a chore. Using imaging technology to guage brain activity, Mehta and fellow researchers found obese subjects also expended more mental resources when walking, even though they were able to walk as well as non-obese test subjects. And stress further taxed the brain of obese individuals, compared to their normal-weight counterparts. In addition to the physical challenge, the added mental burden of obesity might also lead individuals to tire more quickly, Mehta says.