While it sounds like an urban legend, gaining 10 pounds on a 7-day cruise is physically possible but statistically unlikely to be entirely fat. To gain 10 pounds of actual body fat, a person would need to consume a staggering 35,000 calories above their daily maintenance level—roughly 5,000 extra calories per day. However, a significant "weight gain" on a cruise is often a combination of water retention, inflammation, and glycogen storage. Cruise food is notoriously high in sodium, which causes the body to hold onto several pounds of water. Furthermore, the increased consumption of carbohydrates (unlimited bread, pasta, and desserts) refills the body's glycogen stores, which also carry water weight. Combined with alcohol consumption and less sleep, a traveler might step on the scale upon returning home and see a 10-pound increase. The good news is that much of this "cruise weight" typically vanishes within a week of returning to a normal diet and hydration routine. To minimize the gain, savvy cruisers try to take the stairs instead of the elevator and balance the "midnight buffet" with visits to the ship's fitness center or participating in active shore excursions like hiking or snorkeling.