Reduce the obesity rate in New York City? Fat chance!

More New Yorkers than ever are living large, despite Nanny Bloomberg’s war on sugary drinks and fast foods, statistics obtained by The Post reveal.

The city’s obesity rate among adults has skyrocketed 25 percent since Mayor Bloomberg took office in 2002, city Health Department figures show.

That year, nearly one in five New Yorkers was considered obese. Now almost one in four is.

The figures are surprising given Gotham’s residents are doing better according to other health indicators.

For example, the percentage of adults who drink one or more sugar-sweetened beverages a day dropped to 28 percent last year from 36 percent in 2007, says the Health Department’s Take Care New York 2012 report.

The data also show more people are physically active and eating vegetables.

Both improvements come after Hizzoner pushed for the expansion of bike lanes and healthier school meals.

The city also banned unhealthy trans fats from eatery menus starting in 2007.

The obesity epidemic is one reason Bloomberg and city Health Commissioner Tom Farley issued the edict last year to limit the sizes of soda and other sugary drinks to 16 ounces. It has been struck down in court.

Health officials admit fat is a formidable foe.

“Despite recent declines, sugary-drink consumption remains far higher today than it was in the 1970s, when the obesity epidemic began to surge,’’ a department spokeswoman said.

“Nationwide, adult obesity rates have been going up for at least the last 30 years, and we expect a lag in changes in the adult obesity rate after a change in diet.

“We are seeing declines in obesity in children, and [the] fall in sugary-drink consumption may have prevented our city from having even higher obesity rates.”

Nutrition experts praised the Bloomberg administration for releasing anti-obesity ad campaigns and requiring calorie counts for meals in fast-food joints.

But they said education goes only so far.

“It’s easier to gain weight than lose weight. We live in a toxic environment of junk food and excess. It’s a culture we still embrace,” said Lisa Young, an NYU nutrition professor who writes The Portion Teller blog.

Noting that the city cut tobacco use by banning smoking in bars and restaurants and boosting cigarette taxes, Young said similar efforts must be waged for obesity.

“We need radical change in the environment. That’s why I supported the soda ban,” she said.