The study looked at more than 30,000 participants, who were set challenges such as quitting smoking, and what effect incentives had.
The team from Newcastle University looked at 16 previous studies and found that as little as £3 could make people up to 50% more likely to change their behaviour, when compared with usual care or no intervention.
Financial penalties were also found to work but they concluded that larger incentives were no more likely than smaller ones to be effective.
The team said they were not clear if the effects would continue after the rewards had stopped and said more work needed to be done to calculate whether the policy would save the NHS money in the long run.
Dr Jean Adams, senior lecturer in public health, said: "We were surprised how few studies we found which had looked at the impact financial incentives can have."