Vacation souvenirs, from T-shirts to snow globes, that prove you’ve “been there” are lots of fun to collect over the years. Unfortunately for many adults, picking up a few extra pounds on vacation is an unwanted souvenir of good times, too.

According to a University of Georgia study, the small but steady creep of weight gain most adults experience over the years often sneaks in while we’re on vacation. The study found that a one- to three-week vacation is linked to an average of nearly a 1-pound weight gain.

“If you’re only gaining a pound or two a year, and you gained three-quarters of that on a one- to three-week vacation, that’s a pretty substantial weight gain during a short period of time,” said Jamie Cooper, an associate professor of nutrition in UGA’s College of Family and Consumer Sciences.

Previous diet studies have confirmed weight gain during the “turkey, gravy and all the trimmings” holiday season, but this is the first to link weight gain to short-term vacations. So much for the “summer of fun.”

What about all of that walking, hiking, biking, swimming, tennis, golf and paddleboarding so many people enjoy during their free time? Sorry, more sobering news: The weight gain occurred despite a trend for slightly increased physical activity during vacation.

“You might be a little bit more active, but it’s not enough to compensate for the extra calories you might be eating or drinking on vacation,” Cooper said.

Another weight-gain whammy: The study showed a decrease in physical activity in the weeks following vacation.

Hold the piña coladas

No big surprise, but a big impact on calorie intake: The study found participants ate and drank more when living it up on vacation. Alcohol consumption doubled from an average of eight drinks a week to 16 per week.

Tipsy tip: Seek out lower-calorie cocktails made with sparkling waters instead of sugary mixes, and avoid drinks made with high-fat coconut cream.

To help prevent body fat from taking a “staycation,” Cooper suggests weighing before and after any long trip away from home. “If you’ve gained 3 pounds, then work really hard in the next couple of weeks to take those 3 pounds off, because if it stays on long enough, it gets really hard to take off.”