Their job is to protect and serve – but it seems some police officers interpret this as an excuse to enjoy too many extra servings at the lunch table.

A study has revealed US cops have the highest rates of obesity among any profession in the country.

Along with firefighters and security guards, nearly 41 per cent of boys in blue are obese, according to a study in the American Journal of Preventive Medicine.

Letting it all hang out: this NYPD officer is one of the nearly 41 per cent of his colleagues who are obese

Social workers, clergy and counsellors come in second, with 35.6 per cent having a body mass index (BMI) of 30 or more – the standard definition of obese used by the study.

Home health aides and massage therapists are third at 34.8 per cent.

Surprisingly sedentary professions such as truckers, bus drivers and crane operators, come in only fifth in a group with garbage collectors on nearly 32.8 per cent.

The slimmest workers are economists, scientists and psychologists, of whom 14.2 per cent are classed as obese.

Source: American Journal of Preventive Medicine

Police officers, firefighters and security guards could do with taking it easy on the doughnuts, says the study

Other svelte professions at the bottom of the list are artists, actors, athletes and reporters.

The proportion of all American workers who are obese is 27.7 per cent, according to the 2014 study.

Roughly one-third of US adults are obese, which costs companies more than $73 billion a year in healthcare bills and lost working hours and productivity, according to researchers from Duke University.

Some firms have started trying to tackle the problem by paying for employees’ weight-loss surgery, providing them with wearable fitness trackers and competitions on social apps and offering counselling designed to get them to shed the pounds, according to the Wall Street Journal.

Last year, Americans spent $60.5 billion on efforts to lose weight, according to research firm Marketdata Enterprises.

BMI is a measure of relative weight based on a person’s mass and height.

A healthy range is from 18.5 to 25, with anything over that mark considered to be overweight.