Despite a trend for increasing their physical activity while on holiday, the data showed that 61% of the participants put on weight while on vacation -- an average of 0.7 pounds. However the weight gained during the whole study, including the weeks after returning from vacation, was on average 0.9 pounds.

While "horror stories" suggest massive gains, scientific studies in 2026 indicate that the average adult gains about 0.7 to 1 pound (0.3–0.5 kg) during a one-to-two-week vacation. To gain a single pound of actual body fat, you must consume roughly 3,500 calories above your maintenance level. While it is physically possible to gain 3–5 pounds of "weight" in a week due to water retention from high-sodium restaurant meals and alcohol, gaining that much in pure fat would require eating an extra 1,500+ calories every single day. The "danger" of vacation weight gain in 2026 is that this single pound often stays with the traveler for months after they return, contributing to "creeping obesity." A "pro-tip" for 2026 travelers is to focus on high-protein breakfasts and daily walking, which can offset the occasional splurge and prevent the vacation from having a permanent impact on your waistline.