Just as the US entertainment industry has taken over the imaginations of Irish children, the American lifestyle has taken hold of their bodies. One in four US children is obese, and Irish children are rapidly catching up, thanks to sedentary habits and an abundance of high-fat processed foods.

In the US obesity is regarded as the most significant health problem among children because it leads directly to adult morbidity and mortality.

Obese children have higher blood pressure and higher cholesterol than children of normal weight, making childhood obesity an important predictor of future heart disease risk. So serious is the problem that a government-appointed expert panel suggested that public health agencies should consider curtailing advertising of nutrient-poor foods directed towards children and adolescents.

Perhaps we should consider this, too, because now "overweight is over here". The obesity problem among Irish teenagers was highlighted during the week by Prof Denis Gill, a paediatrician at the National Children's Hospital in Temple Street, Dublin, who described four record-breaking paediatric weight problems on his caseload late last year.

These were a two-year-old who weighed 27kg (over four stone), a four-year-old who weighed 38kg (7.5 stone), a seven-year-old weighing 71kg (over 11 stone) and a 13-year-old weighing 123kg (well over 19 stone).

"Irish children are likely to become increasingly fat," he predicts. "The evidence is already present. The bedside lockers of the hospitalised children contain litres of sweet drinks, kilograms of confectionery and great bags of crisps.

"Sweet-drink sales, sweet consumption, starchy, salty convenience food ingestion and crisp-munching are at an all-time high. I suspect that the next generation of infants will have their powdered milk formulas made up with 7-Up."

A dramatic increase in childhood obesity is a trend across Europe. While there is a lack of research into the subject in the Republic, we do know that 20 per cent of nine- to 11-year-olds think they need to lose weight.

In Scotland, where the lifestyle is similar to that in the Republic, 4 per cent of children are obese and a further 18 to 20 per cent are overweight, a good indicator of what may be happening here, according to Emma Ball, lecturer in the Department of Nutrition at the Dublin Institute of Technology.

In Australia, children's average body mass index (the ratio of height to weight) has increased by 4 per cent since 1985.

Obesity is a form of malnutrition, and poor diet is obviously partly to blame, but TV-watching is also significant. A randomised controlled trial of 200 nine-year-olds in California found that children lost weight as a direct result of reducing television, videotape and video-game use as part of an educational programme introduced in two schools.

The Journal of the American Medical Association, which reported the research, concluded that switching off the TV "may be a promising, population-based approach to childhood obesity".

Playing, running and jumping should be an intrinsic part of childhood, but not to the current generation of Irish couch potatoes. A US panel of experts at the American College of Sports Medicine recommended that children exercise for 30 to 40 minutes a day, that schools build more physical exercise into the curriculum, and that safe facilities where children could be active were urgently needed.

In the Republic, more and more parents are afraid to let their children out of the house to play, and there is a lack of sports facilities. Exercise does not have to involve special equipment: something as simple as walking or cycling to school can make a huge difference.

Two other major risk factors almost doom a child to obesity from birth: having obese parents and not being breast-fed. Parental obesity more than doubles the risk of adult obesity among both obese and nonobese children under 10 years of age.

As for breast milk versus formula, if you were looking for a magic solution to prevent obesity, breast-feeding would be it. Children who are breast-fed for one year have a less than 1 per cent incidence of obesity. Being breast-fed, even for two months, halves the risk of obesity, regardless of socio-economic factors.

In his article, Prof Gill also describes how a generation of mothers are nurturing their infants by stuffing foreign objects into their mouths as soon as they emerge from the womb. Day and night "dummy"-sucking is soon followed by mineral sucking through straws, while chewable food is going off the menu altogether, replaced by sloppy custards, yoghurts and other foods of toothpaste consistency.

Home environment is the major influence on obesity. Parents who have problems with food and unhealthy eating habits predispose their children to having poor eating habits. Some 15 per cent of Irish adults are obese and nearly half are overweight, making us among the fattest in Europe. So, of course, Irish children are growing fat, too.

US research has shown that obesity is most common in lower socio-economic groups, but that does not mean that the middle classes are immune. Some conscientious parents may actually be encouraging their children to become overweight without realising it.

Babies and pre-school children have an innate ability to control their calorie intake; the problem is that adults have no respect for children's internal hunger clocks.

When a child says, "I'm hungry", feed him or her, and when a child says "I'm full", stop feeding, advises Dr Susan L. Johnson of the Centre for Human Nutrition at the University of Colorado School of Medicine.

If your child comes up to you at 5 p.m. and says "I'm hungry", and you say "You can't have anything now. We're eating in an hour", it tells the child that the way they feel - their hunger - is not as important as the time on the clock. Instead of ignoring the child's hunger cue, a parent should give raw vegetables. This response reinforces the child's appetite cues, provides a nutritious snack, and allows the parent to continue preparing the family meal, she suggests.

Prof Gill constantly hears parents ask: "What can I do to get her to eat vegetables?" Show by example. Serve and be seen to enjoy fruit, vegetables and low-fat foods. Don't worry if your children reject them.

Children learn to like the foods to which they are exposed. A child needs to taste a new food eight to 10 times before learning to like it. If the parents persist and refuse to give up after two or three rejections, the chances are that their children will broaden their palates.

But there is a wider issue, too, which is of children confusing food with nurture. Comfort-eating in front of the TV in a house where both parents are out working has already been noted by paediatricians in Europe.

With the woeful lack of childcare and support for families in the State, such a scenario seems inevitable here.