Warning: the Surgeon General suggests that you take the following with a grain of salt. It worked for me, though.

I was born before 1960. How long before, I'm not telling. One biological effect of aging is that the body begins to store fat in the midsection, occasionally in response to even the aroma of good food. The aphorism "a moment on the lips; a lifetime on the hips" was developed by a woman in Peoria who was born prior to 1960 and who discovered through scientific testing the validity of the formula E=mc2, where E = the total number of calories in a particular food, m = the fat cells added by eating said food, and c2 = the resultant underwear size. Or something like that.

In any case, calories and cruising have more in common than the mere fact that they begin with the letter "c." It is literally possible on some ships to eat twenty-four hours a day for the entire length of the cruise. I know this because my youngest son attempted it with more than partial success on his first cruise. In fact, an actual scientific study demonstrated that the average increase in body weight for a seven day cruise is seven pounds per person -- or a pound a day. Though this sounds a piffling amount, consider the fact that on one of those new gigaships that carry 3,000 passengers, this represents a net increase in passenger weight of 21,000 pounds, or 10.5 tons. Stated another way, that's enough body mass to create 131 brand new people weighing 160 pounds each. Perhaps this explains why the captain sometimes blows the ballast tanks on the way back to home port.

With all of that delicious food lying about on a cruise, how the devil do you actually lose weight? If you suspect I'm going to reveal some secret herbal concoction that melts fat away, or give you the name of a new wonder drug, I'm afraid you will be sadly disappointed. There's really no secret to it at all -- it's all diet and exercise.

Now wait a minute, before you hit the "back" button, I want you to know that I ate anything I wanted on this mythical weight loss cruise, and never set foot in the fitness center. When it comes to exercise I tend to agree with that quintessentially fit astronaut, Neil Armstrong, who said "I believe every human has a finite number of heartbeats. I don't intend to waste any of mine running around doing exercises."

So just how did I lose weight on my last cruise? I simply maintained my normal (if you can call it that) routine and did not run around eating everything I saw on a platter with a toothpick stuck in it. This was not a version of the Mark Twain diet. As Twain wrote, "the only way to keep your health is to eat what you don't want, drink what you don't like, and do what you'd rather not." No, my tried and true cruise weight-loss secrets are simple and painless, and only involve a little bit of doing what you'd rather not:

• Have a continental breakfast en suite in the morning. This both allows you to sleep in if you want, and means you will likely consume a few less calories than those frequenting the formal dining room (or even the Lido deck buffet). If you have a balcony cabin, you'll feel privileged and superior to all those other masses of folks chowing down in the dining room anyway.
• Drink plenty of liquids, water, seltzer, or diet drinks during the day. This will keep something in your stomach but won't load you up with calories.
• Buy a big bag of pretzels ashore and throw it in your beach bag when you go up on sun deck to lounge by the pool. This takes care of the nibbles with a low-fat snack.
• If you must eat lunch, stick with the fresh fruit section of the buffet line, or have a light salad. Save those calories for dinner.
• If you simply cannot bear to miss the midnight buffet, just take photographs of it like all the other first-time cruisers.
• Don't take the elevator. Stair climbing burns thousands of calories an hour. Well, hundreds at least.
• Skip that guided bus tour around those postage stamp-sized port villages and take a walk on your own. You'll save money and burn fat at the same time.
• Splurge on dinner and have whatever you want. Dinner always represents the best available food during a cruise and if you enjoy yourself at dinner you won't mind denying yourself breakfast.
• If it doesn't put a crimp in your evening routine, take First Seating dinner. This allows you to digest some of the groceries before you turn in for the night.
• Dance up a storm. Your wife will appreciate it and you might have fun.

Of course, if you're a first-time cruiser, or only go once every few years, please ignore all the above and stuff yourself silly. One of the pleasures of a first cruise is the memory of that continual aura of contentment that a slightly overstuffed stomach gives rise to. Or, as Fran Lebowitz so eloquently put it: "Favorite animal: steak."

But if you are a frequent cruiser, and you don't want to purchase a new wardrobe for every voyage, or keep explaining that no, you're not bulking up to try out as a defensive lineman for the Green Bay Packers, try a few of the tips above.

Happy cruising.

Brent Betit is a freelance writer who lives in Vermont with his wife and two young children.

Brent has written many SeaLetter columns on such subjects as sea-going language, cruising with kids and cruise etiquette. To find all of Brent's SeaLetter columns and cruise reviews, use the SeaLetter Search Engine entering "Brent Betit" as your search phrase.

Brent is always interested in your comments and suggestions and may be reached at: Brent@sealetter.com.