Obesity is a “growing global epidemic,” says the WHO. More than one billion people worldwide are obese and childhood obesity has quadrupled since 1990.

In 2025, Italy became the first country to pass a national law recognizing obesity as a chronic, progressive and recurring disease.

Rather than treating obesity simply as a result of poor decisions, the country’s new law recognizes it as a chronic disease influenced by biology, environment and social circumstances.

The Campania region has become a testing ground for putting that philosophy into practice, implementing a series of ambitious interventions, including a controversial trial of a “fasting-mimicking diet.”

Researchers are recruiting 300 overweight adolescents who will spend five days every three months on a controlled diet of 1,100 calories on the first day and 770 calories on the next four days, so restrictive that it resembles fasting.

The goal is to cause a “metabolic reset.”

“Fasting, or controlled food deprivation, is linked to a longer, healthier life,” says Dr. Longo, who has spent three decades studying the effects of fasting.

But not all obesity specialists are convinced that fasting is the right approach for children.

Pediatrician Berni Canani believes that the evidence on diets that mimic fasting in children is still too limited to be recommended in Italian clinical guidelines.

She also worries that restrictive diets could carry psychological risks for teenagers, whose relationship with food is still developing.

“I fear that imposing dietary restrictions on teenagers could increase the risk of eating disorders, anorexia and body dysmorphia,” she says.

Meanwhile, Salvatore hopes to have surgery in the summer so he can, for the first time in years, put on a swimsuit without feeling self-conscious.

But he is not alone. Across Italy, a generation of children is growing up increasingly removed from the Mediterranean diet for which the country once was famous.

Additional reporting by Bob Howard.