The regulations are changing next season with the introduction of a new V6 turbocharged power unit with energy recovery systems which will weigh considerably more than the current V8 engines.
At present the car and driver - in overalls - must weigh a minimum of 642 kilos but while that will go up to 692kg next year to compensate for the new unit, some drivers argue it is not enough and gives the lighter men a significant advantage.
They would like a further 10kg to be added on to the combined weight.
"Everybody's been asking me why I look so skinny but you have to be skinny because it's to your advantage to be as light as possible," Red Bull's Webber told reporters at the Korean Grand Prix. "It's a car performance advantage.
"The lighter drivers should be pushing as well (for an increase in the minimum weight) but they don't because obviously it's nice for them," added the Australian, who is leaving Formula One at the end of the year and whose triple-champion team mate Sebastian Vettel is considerably shorter and lighter.
While those weighing 60kg will have the car at the optimum weight and have scope to use ballast to maximum effect, others - such as Sauber's German driver Nico Hulkenberg who weighs in at around 78kg - will be at a considerable disadvantage.
Hulkenberg's physique is already believed to have counted against him for a drive with top teams such as Ferrari and McLaren and that has made the subject a talking point in the paddock, particularly among German media.
Red Bull team principal Christian Horner told reporters Hulkenberg had not been on their list to replace Webber but, if he had been, his size would have counted against him.
SKIN ON BONES
Hulkenberg said he expected the Grand Prix Drivers' Association (GPDA) to discuss the situation as teams finalised their 2014 car designs and bigger drivers began to feel the squeeze in contract talks.
"I'm 74-74.5 kilos with my kit, and even I struggle to make the weight limit. I have done for the last three years," said 2009 champion Jenson Button, who is a GPDA director and will be at McLaren again next year.
"I love fitness training, but there is certain fitness training I have to do and parts of my training I can't do. I can't build muscle and I can't eat carbohydrates because I have to be a set weight, and it's going to get worse next year as well," added the Briton.
Button said some teams were sure to start next season without any ballast, which they move around to balance the car, to keep the car as close to the legal minimum as possible and some drivers could even see their careers threatened.
"It does hurt the heavier driver, and it's very unfair to say 'lose weight' because some of us can't lose any more," said Button, who reckoned 10 extra kilos equated to three-tenths of a second in lap time.
"You need to have skin on your bones, and a little bit of muscle to drive a Formula One car, so it is unfair.
"They are always trying to push the boundaries but in terms of weight limit, I can't see a reason why we can't put the weight limit up by 10 kilos," said Button. "It wouldn't penalise half of the grid next season.
"It's one of the easiest things to put right - it could save a driver's career, or make a driver's career."
- Motor Racing
- Nico Hulkenberg