Dieters who want to keep the weight off should make sure they are walking 8500 steps per day, new research suggests.

Experts who compared a group of people dieting and exercising with a group dieting alone or not receiving any treatment found daily steps were a crucial factor in preventing weight regain.

The research, being presented at the European Congress on Obesity in Istanbul, Turkey, will also be published in the International Journal of Environmental Research and Public Health.

Marwan El Ghoch, from the University of Modena and Reggio Emilia in Italy, who led the study, said around 80 per cent of people who initially lose weight tend to put some or all of it back on again within three to five years.

"The identification of a strategy that would solve this problem and help people maintain their new weight would be of huge clinical value," he said.

Professor El Ghoch and colleagues in Italy and Lebanon analysed 14 existing studies on the issue to look for themes.

These studies included 3758 people with an average age of 53 who were overweight or obese, from countries including Australia, the UK, US and Japan.

Overall, 1987 people were on lifestyle modification programs, including eating healthily and walking more.

Another 1771 people were either dieting alone or not receiving any treatment and acted as the comparison group.

The programs had a weight loss phase, followed by a weight maintenance phase, where the aim was to keep the weight off in the long term.

A person's daily number of steps was measured at the start of the trials, at the end of the weight loss phase (average 7.9 months) and at the end of the weight maintenance phase (average 10.3 months).

Both groups of patients were found to have a similar step count at the start (7280 in the lifestyle group and 7180 in the comparison group), indicating that they had similar lifestyles.

Researchers found that, overall, the control group did not increase their number of steps and did not lose weight at any time.

However, in contrast, the group following the lifestyle advice programs increased their step count to 8454 a day by the end of the weight loss phase, losing 4.39 per cent of their body weight on average, or around four kilos.

At the end of the weight maintenance phase, these people were still walking and doing 8241 steps per day.

They also kept off most of the weight they had lost (with average weight loss at end of trials being 3.28 per cent, or around three kilos).

Researchers concluded there was a clear link between increasing step count and preventing weight regain, though during the weight loss phase it was reduced calorie intake that seemed to play the biggest role.

"Participants should be always encouraged to increase their step count to approximately 8500 a day during the weight loss phase and sustain this level of physical activity during the maintenance phase to help prevent them from regaining weight," Prof El Ghosh said.

"Increasing the number of steps walked to 8500 each day is a simple and affordable strategy to prevent weight regain."