The incidence and seriousness of childhood obesity is increasing, especially among boys, according to a survey conducted by the First Pediatric Clinic of Athens University on 10,925 infants, children and adolescents in the Greater Athens area. Comparison of the results with those of an earlier study by the same clinic reveals that overweight boys are up to 15 kilos heavier and girls are up to 3 kilos heavier than their counterparts 20 years ago. After the age of 12, however, fewer girls are overweight, as they start altering their diet in order to enhance their appearance. While 10 percent of boys are overweight (ranging from 9.17 percent to 11.8 percent across different age groups), only 3.5 percent of girls (3.3 to 3.65 percent) have the same problem. This phenomenon, which is confirmed by two other studies, is hard to explain. George P. Chroussos, professor of pediatrics at Athens University, attributes it to the greater emphasis society places on girls’ appearance and their own interest in their looks from puberty onward. Mediterranean first Although the percentage of overweight children in Athens is high, comparative statistics show that it is lower than in other Mediterranean countries, particularly among girls. A recent study that evaluated data from various European states showed a rather high percentage of obesity among children and adolescents, which rises from north to south. The Athens study was conducted at nursery schools run by the City of Athens and the Health Ministry, maternity hospitals, health centers and schools in 25 municipal wards. It showed that the incidence of obesity among girls is fairly low, except for their first year of life when it is high (9.16 percent). Girls have their lowest body mass indicator (BMI = weight in kilos divided by the square of the height in meters) at the age of 3.5 to 4, after which it gradually increases. Obesity is uniformly high among boys of different ages, while a large percentage of boys aged 1 to 6 (10.88 percent) and 13-18 (20.63 percent) are overweight. «It is hard to define obesity in childhood and adolescence,» says Chroussos, «when children’s height and weight keeps changing. But one can define the normal BMI, above which there is a heightened risk of late-onset diabetes or heart problems. A pediatrician can easily use diagrams to ascertain whether a child is obese. «From the age of 18 onward, a BMI of 25 is considered normal, above 25 overweight and above 30 obese. Every BMI unit above 25 is considered to raise the risk of ailments such as diabetes by 10 percent. «A normal BMI for a child of 14 is not 25 but 23. BMI is very useful because it takes height into consideration as well as weight.» Obesity is a problem to a greater or lesser extent in most European countries. The epidemic mainly affects children aged 7 to 11, with 12 to 36 percent of primary school pupils in European being overweight or obese. At that age, Greek children as a whole are lighter than their counterparts in Italy and Spain, mainly because Greek girls weigh less. In Greece, 23 percent of children are overweight (28 percent of boys and 17 percent of girls), as against 36 percent in Italy and 34 percent in Spain. The percentages of overweight children are much lower in Britain (20 percent), France (19 percent), Sweden (18 percent) and Denmark (15 percent). But in those countries, the number of overweight children does not change significantly at puberty, whereas in Mediterranean countries, many children lose weight in adolescence, lowering the number of overweight adolescents to 21-23 percent. This trend is not in evidence in Greece, mainly due to Greek boys, who add kilos during adolescence.