There are two ways of observing things when you're on a cruise ship: outwards, towards the horizon, enjoying the the Sun, the Moon, the stars and the gentle breeze touching your face; or inwards, watching your fellow passengers and taking note of their faces, bodies and behaviors. Well, on my last trip I looked inwards and what I saw was a lot of fat people. The sad thing was that many of them were kids.

      I've always been averse to cruises. The idea of being trapped for three or four days, without any possibility of escape on the high seas if you're feeling overwhelmed by people or boredom, made me nauseous. But with the idea of a different kind of vacation with my children, I embarked upon the sea adventure. And what I saw horrified me.

      Though I wasn't bored, I did feel overwhelmed by people; it's impossible to avoid this when you share everything, day and night, with 3,000 other passengers in a given space. However, what took me by surprise was the vast number of overweight children.

      The pool area was a terrible tribute to junk-food, to excessive food and to the lack of exercise. I saw kids around 8, 9 or 10 whose stomachs bulged grotesquely in their colorful turquoise-blue and Mexican-pink bathing suits. I saw big round cheeks, the size of baseballs, on teenagers who knocked back a quart of soda as if it were water. And then I saw a kid not much older than 6 whose skin seemed to burst with sun and corpulence, and whose tree-trunk-legs were so huge that when he walked he had to rock from side to side to maintain balance and drag his feet.

      Every time one of these kids threw themselves down the giant slide into the pool, it was as if a tsunami erupted. And when they jumped, curled in a ball, into the water to soak those around them, they managed also to drench unprepared tourists yards away.

      The children on the cruise, of course, did not come alone. There is, I believe, a direct relationship between obese parents and obese children. And my theory was right: The parents who heaped food on their plates, serving themselves a steak, two chicken legs, three orders of pasta, four heaped ladels of rice, five giant shrimps, six desserts and a token pinch of salad were the ones who had fat children. Obesity is a disease, yes. But it's also something learned at home.

      The idea of "all you can eat" generated such enthusiasm among the passengers that they were seen helping themselves three and four times from the buffet. There are people who eat as if the world is about to end and their limit seems to be the back of their throats. And for every adult who walked away olympically with two overflowing platters in their hands, you would often see one or two children following them, with ice-cream or pancake syrup dripping down their fingers.

      One out of every three adolescent youngsters in the United States suffers from obesity.

      And it is reaching epidemic proportions. For example: The number of overweight children under 18 in California schools, according to the California Center for Public Health Advocacy, increased from 26 percent in 2001 to 28 percent in 2004.

      Why? On its Web site, the controversial film "Supersize Me" gives us a clue: The most popular vegetable in the United States is French fries; Americans devour the meat of 1 million animals per hour and spend $110 billion a year on fast-food. With these data on the table, it's no surprise that former National Health Adviser David Satcher has said, "Fast food is a major contributor to the obesity epidemic" in the United States.

      This is a country of excess when it comes to food. Nowhere in the world have I seen bigger portions or people who eat so much in so few minutes than at American restaurants. Most of the passengers on this cruise were from the United States and their waistlines confirmed the statistics by the American Obesity Association: 127 million Americans over 20 years old are obese or overweight. That is, two out of every three Americans (64 percent) have excess poundage.

      I have never before seen so many fat children at sea. And many of those who started out slim or at a correct weight ended up looking a bit like their cruise mates.

      We can blame their parents, or America's excessive food, or the lack of public education on healthy nutrition, or sitting in front of a computer where exercise consists of surfing the Internet, or the hamburger restaurants or the buffets where you can eat until your stomach bursts. Maybe, all of these contribute to this epidemic.

      Too bad I realized this when I was on vacation. Reason enough for me never to sail aboard another of these floating food emporiums again.