There's many ways to try to secure a job: Brush up on the business; practise your answers; dress smartly.
But it seems one of the quickest methods for women to win that role might simply be to lose some weight.
Research shows even those who are as little as a pound (0.45 kg) heavier than their rivals are at a disadvantage because of weight-based prejudice in the workplace.
Even women whose BMI is in the healthy range are penalised for their figures - with womenbosses being just as guilty of the prejudice as men.
Professor Dennis Nickson, of University of Strathclyde Business School - who led the study - said the findings were "deeply unsettling".
"In service sector employment, women on the upper end of a normal and medically healthy BMI range face greater weight-based prejudice than men," he said.
"Even a marginal increase in weight appears to have a negative impact on the hireability ratings of female job applicants.
"For women, it seems, even seemingly minute changes to the shape, size and weight of the body are important."
The report come days after a leading recruiter suggested women should ditch their engagement rings if they want to secure a job.
Bruce Hurwitz, an executive recruiter from New York, said men who see a fancy ring will assume the woman to be "high maintenance".
The latest study asked 120 men and women to rate eight pictures of women for their suitability for jobs working with the public, such as in a shop or in a restaurant or office.
Participants were told the women, who had a BMI of around 18.8 - considered healthy - were all equally qualified and the only criteria was looks. They also repeated the experiment with pictures of men ranging from normal to overweight.
The researchers found that marginally 'heavier' female faces were rated lower on hireability - showing that a subtle increase in BMI, even within the healthy range, "'is a very real stigma that negatively impacts on women's life chances".
The greater a woman's weight the less likely she was to be given a job, particularly in jobs dealing with the public, the study found.
The researchers added: "Interestingly, the sex of the respondent was not significant in any of these evaluations. Women respondents in our study were equally likely to rate 'heavy but healthy' female job applicants just as negatively as the male respondents.
"The main conclusion of this paper is that women within the normal BMI range appear to suffer greater weight-based bias than men who are overtly overweight.
"This research speaks to the challenges that women (and to a lesser extent men) face in what appears to be a highly 'weight-conscious' labour market."
Some employers have openly admitted they prefer to hire slimmer workers. They include US clothing firm Abercrombie & Fitch, which has in the past been accused of 'look-ism' - only employing young, slim and attractive assistants.