Discrimination on the basis of sex, race, religion, age or sexual orientation will quickly see employers falling foul of the equality police. But employers in the UK who discriminate against obese job candidates are quite within their rights to do so - as long as there is no medical reason for their weight problem.
According to law firm DWF, UK law offers no specific protection against 'fattism'. But being overweight is not sufficient grounds to sack an existing employee unless it is affecting their performance, the firm warns.
"With the nation's waistlines getting bigger, weight is increasingly becoming an issue for employers and some have sought our advice," said DWF's Stephen Robinson.
"You can choose not to employ an overweight candidate, provided there is no underlying medical reason for it, although you should take the precaution of asking all candidates as part of the application process whether they suffer from a disability and whether they would need support or assistance should they be employed."
Fail to ask these questions, he warned, and there is a risk that employers might be adjudged to have discriminated against them.
It would also be dangerous to dismiss someone because of their weight unless it clearly had a detrimental impact on the business, he added.
"If an employee is underperforming due to excess weight, provided there is no underlying medical reason, you should take them through your capability procedure sensitively, by highlighting how their excess weight has caused a performance issue, its effects on the business and what both employer and employee should do to resolve the issue.
"It may be that you set a timescale for them to lose weight and provide them with the support they need to achieve the goal. However, if once you have exhausted the procedure and there is no option but dismissal you must be clear that the reasons for dismissal relate to their capability to do the job and not simply because you object to their weight."
But a more effective long-term solution is for employers to take a lead in encouraging staff to stay fit and healthy, Robinson argued.
"Consider offering subsidised gym membership and encourage team building sports, offer weight loss and healthy eating advice and include healthy and low-fat foods in vending machines and on the menu in the staff canteen. Installing bike sheds and showers will encourage employees to walk, run or cycle to work.
Obesity can cause increased absence and reduced productivity and this time of year, when New Year resolutions are uppermost in people's minds, is an ideal opportunity to take a proactive approach to combat it."