The report found 2.13 million children and young people between the ages of three and 17 years old are overweight or obese.
Of those, two million “do not play sport or do any other form of exercise,” the study's authors wrote.
The report said that, while 74.2 percent of Italian children eat fruit and vegetables every day, only 12.6 percent have the recommended four or more portions.
Meanwhile, a quarter of Italian children consume sweets and fizzy drinks every day.
The study found geographical differences in the results, with childhood obesity more likely in the south of the country. The lowest levels were found in the north-west of Italy (18.8 percent) while in Campania the figure was 35.4 percent.
The study also pointed out that Italy has one the highest levels of obesity among children aged seven-to-eight years old in Europe.
Some 18 percent of children in Italy and Spain were found to be obese. The only country which recorded higher levels of childhood obesity was Cyprus, with 20 percent.
In total around one in ten Italians are obese, according to figures from the OECD, while a further 22 million Italians are overweight.
Italian dieticians are calling for an end to discrimination against obese people, stressing that obesity should be recognised as “a disease and not an aesthetic problem.”
“So far preventative interventions have proved ineffective because they are based on the paradigm of personal responsibility… in reality, obesity is a complex condition that derives from the interaction of genetic, psychological and environmental factors,” stated Dr. Giuseppe Fatati, president of the Italian Obesity Network.