It’s a common problem among retired athletes. Athletic activity slows, but the appetite doesn’t … so the pounds pile on. For football players at the youth, collegiate and professional levels, being overweight in retirement could pose another problem, too.

Those with a lot of hits under their belts are already at risk for brain trauma from multiple concussions, and carrying extra weight could compound the conundrum. The study, published in the journal Translational Psychiatry, found that retired pro football players who are overweight suffer from more thinking and memory problems than those who stay fit post-gridiron.

Scientists compared blood flow in the brains of healthy weight players and overweight retirees. Heavy players had less blood flow to areas of the brain responsible for attention, reasoning, organizing and planning. They also performed worse on tests measuring attention and memory. Scientists believe the extra burden of obesity increases the release of inflammatory markers associated with impaired brain function.

In fact, another study found retired football players have an increased risk for mild cognitive impairment, which is a precursor for Alzheimer’s disease. Concussions and traumatic brain injuries are a common injury in football, even with helmets. They happen when a hard collision causes the brain to bump against the skull, resulting in dangerous bruising or even bleeding in extreme cases. Symptoms include dizziness, blurred vision, confusion and nausea. The best remedy for a concussion is rest — the brain needs to heal. The worst remedy is another hit to the head, which can cause permanent damage.

So whether you’re a parent, coach, spectator or player be sure to keep your head on straight, play smart and take a time-out if concussion symptoms appear. Like any athlete, a brain needs rest, too.