Rome, January 25 - One in seven residents of Molise - or 13.5% of the adult population - are obese compared with a national average of 10%, putting the small southern region at the top of the Italian obesity charts, the national statistics institute said Friday. The southern region of Basilicata came in at second place with an obesity rate of 13.1% followed by neighbouring Puglia with 12.6%, according to the 2013 edition of the Istat Noi Italia report. Instead the slimmest regions were Liguria and Val d'Aosta with 8.3%, followed by Tuscany and Abruzzo (8.7%), Lombardy (8.9%) and Lazio (9.2%). The figures were based on the adult population and updated to 2011. "Even though the figures are lower than in other European countries we must not underestimate the situation," said Marcello Lucchese, President of the Italian society of obesity and metabolic surgery. "The number of obese Italians has risen by 25% since 1994, including in northern regions". Lucchese said bariatric surgery was "opportune" to protect patients from serious conditions such as hypertension, diabetes and cancer that can result from obesity when diet, physical exercise and drug treatment proved to be ineffective. Obesity in Italy has a social cost of around 23 billion euros a year, of which 11 billion is borne by the national health service. This figure does not include the indirect cost of 65 billion euros per year due to death, decreased productivity, absence from work and unemployment. "Incentivising weight-loss surgery could lead to savings of 88 billion euros," said Lucchese.