Workers on zero-hours contracts are more likely to be happy with their work-life balance than other employees, according to a new study.
The report said the use of zero-hours contracts has been "unfairly demonised" amid controversy over their widespread use.
Employees on the contracts do not know if they will have work from one week to the next, but research among 2,500 adults found that those on zero-hours are just as happy with their job as the average worker, and are more content with their work-life balance.
Just over half of the 456 zero hours workers questioned by the Chartered Institute of Personnel and Development (CIPD) said they did not want more hours, with 38% saying they would.
Four out of five said they were never penalised if they were unavailable for work.
Peter Cheese, chief executive of the CIPD, said: "The use of zero-hours contracts in the UK economy has been underestimated, oversimplified and in some cases, unfairly demonised. Our research shows that the majority of people employed on these contracts are satisfied with their jobs.
"However, we also recognise that there is a need to improve poor practice in the use of zero-hours contracts, for example the lack of notice many zero-hours staff receive when work is cancelled.
The CIPD said that where zero-hours contracts are being used fore the right reasons, they provide flexibility for workers and employers.
The study confirmed CIPD's previous estimate that around a million people are on zero-hours contracts, although other studies have suggested that the figure is much higher.
Steve Radley, director of policy at EEF, the manufacturers' organisation, said: "The debate on zero-hours contracts has become unbalanced and needs greater focus on the benefits it can bring to both workers and employers.
"With skills in scarce supply, zero hours help employers to tap into specialist skills when they are needed and to draw on the experience of older workers. For many workers, zero hours give them the flexibility and they allow older workers to taper the transition from work to retirement."
TUC General Secretary Frances O'Grady said: "Whilst not every employee on a zero hours contract is exploited, this survey shows that job insecurity and low pay are concerns for a significant number of workers, including white collar staff.
"The CIPD guidance will help enlightened employers manage zero hours contracts better. But the real problems lie with bosses who aren't interested in good practice and are more concerned with squeezing staff to boost their profit margins. That's why we need legislative action to stamp out the growing abuse of workers on zero hours contracts and other forms of insecure work."
Shadow trade minister Ian Murray said: " This new research confirms estimates that there are as many as one million people employed on zero-hours contracts, while ministers still insist on using a discredited statistics which are far lower than this.
"It also highlights concerns on bad practice and exploitation, with one in five workers on zero-hours contracts saying their pay is lower than comparable permanent staff and 40% not receiving notice of work not being available.
"While the government has failed to act, Labour would outlaw the exploitative use of zero-hours contracts."
Unison general secretary, Dave Prentis, said: "The CIPD has taken a snapshot of worker and employer views without some of the context. Many of these new jobs are in the public services and they replace permanent jobs. Staff are being forced onto them against their will or face losing their jobs.
"Not knowing from week to week what money you have coming in to buy food and pay your bills can be distressing. Having your working hours varied at short notice is also stressful and it makes planning, childcare arrangements and budgeting hard."