How would you feel if your boss asked you to lose weight so you could carry on doing your job?
That is the reality facing Formula One drivers whose body mass is constantly checked by their employers, the teams.
Leading drivers, including 2009 world champion Jenson Button and Red Bull racer Mark Webber, spoke openly about the problem.
Earlier this month Webber commented on this Twitter page: "Haven't eaten for last 5 years!" He later removed the tweet.
"I love fitness training but there are things I can't do because I have to be a set weight -- not eat carbohydrates, not build muscle," Button told reporters at the Korean Grand Prix, in the city of Mokpo, South Korea.
"I struggle to meet the weight limit. I have done for three years."
Driver weight is a hot topic because next season's redesigned car are heavier.
That means lighter drivers -- such as Felipe Massa, who weighs 59 kilos, will have an advantage over taller drivers like Nico Hulkenberg, who weighs in at 74 kilos.
Just like horse racing and boxing, motor racing has scales to balance.
The car must meet a minimum weight of 642 kilos -- the weight of the car and driver combined without fuel -- to help level the competition but the further the car tips over this ideal weight, the slower it becomes.
Teams also like to have the leeway to add ballast to adjust the balance and handling of the car for each circuit.
The preference is for the car and driver to weigh in below the minimum weight and for ballast to make up the difference. The heavier a driver is the less ballast the teams have to play with.
One way to lose weight is to ask the driver to get skinny -- and this can go on all season long.
"This year we had a problem with weight," Carlos Corell, who manages Caterham driver Giedo Van Der Garde's fitness regime and diet, explained to CNN.
"We try to develop the car but sometimes that means the car is going to be heavier, so when the car is heavier the only way to lose weight is the driver.
"Giedo is one of the tallest drivers on the grid. He is 1.83m. He is around 73.5 kilos with his helmet and overalls on. It's really light.
"We had to lose one and a half kilos -- and that's what we did."
Highly rated Sauber driver Hulkenberg is, like Webber, Button and Van Der Garde, one of the taller drivers on the F1 grid. The German measures 1.84m.
His former manager Timo Gans told CNN that, just like Van Der Garde, Hulkenberg had also been asked by a team to lose weight during the season.
"In 2011, when Nico was third driver for Force India, I spoke to [someone] in a leading position at Force India," Gans explained.
"He told me that they had noticed that Nico's weight had changed a little bit.
"He had gained one and something kilos in two or three months. I was advised to make sure that Nico get his weight back in the limits."
A Force India spokesman told CNN: "Drivers are encouraged to be as fit as possible without sacrificing strength or endurance."
While it is not known exactly how many drivers have been asked to lose weight, Gans explained that teams regularly check a driver's weight.