Memorial Day traditionally marks the beginning of the summer travel season. With the Centers for Disease Control reporting that nearly two-thirds of Americans are overweight or obese, this season is likely to find more travelers packing more pounds than ever.

Many people even expect to gain weight while traveling, not because they want to but because they have no guidance on how to prevent it. To help you avoid returning home heavier than when you left – and in a shameless plug for my book The Complete Travel Diet - I offer up the following five tips:

Eat. While you may not expect to find “eat” as a dieting tip, it is essential to any viable weight-loss or weight-maintenance program. While traveling to your destination, you may go for many hours without the opportunity to find food. Not good. Putting your body in this state of deprivation will cause it to conserve rather than burn fat, and it will make you hungry – “famished” is the word you’ll probably use – causing you to overeat as soon as you get the chance. If you will be spending many hours in transit, take along some healthful snacks to keep your body satiated.

Keep hydrated. Low humidity in airplane passenger compartments pulls moisture from your skin, and high temperatures at your destination can cause your body to perspire. Both consequences redirect water that your digestive system needs to function efficiently. Moreover, a stomach that is filled – even with just water – can lessen the sense of hunger and help prevent you from overeating. So drink plenty of water while on your way to your destination and while you are there as well.

Limit caffeine and alcohol. Alcohol and caffeine can act as diuretics – not the effect you are seeking when trying to keep yourself hydrated.

Walk. Whenever possible, avoid using trams, moving sidewalks, people movers, escalators, elevators or other mechanical conveyances. Take a hike rather than a drive. Walk to the beach rather than hopping on a shuttle. Try to get in some additional time moving rather than sitting and “vegging out.” You can easily burn a few extra hundred Calories a day just by walking.

Enjoy yourself. You’re on vacation. It’s time to unwind and enjoy yourself. Trying to adhere to a strict routine can get in the way of that enjoyment. Instead follow the principle of moderation. Sample smaller portions of a variety of foods, and get out and see the sights.