A new report on welfare uptake shows the number of people who access working-age means-tested benefits is much higher than snapshot figures would suggest.
While only about a fifth of people report receiving such benefits at any one time, more than half do so over an 18-year period, Institute for Fiscal Studies (IFS) research published in the Journal of Economic Inequality found.
The study used data which tracked the same individuals over long periods of time to get a better picture of what was happening in the benefits system.
IFS researchers stated: "Debates about welfare policy often discuss benefit recipients as though they are a fixed, relatively small group of people.
"In reality, people's circumstances fluctuate frequently over their lifetimes, often dramatically and in ways that matter hugely for entitlements to benefits.
"People's health changes, they move in and out of work, their earnings vary, and children come and go."
The study found that the number of adults who fall back on means-tested benefits is likely to be even higher because the estimates are based on survey data which tends to underestimate welfare claims.
The IFS report also raised questions about jobless benefits.
The study states: "While out-of-work benefits look much more effective at directing money to the poorest in any one year, looked at over a lifetime work-contingent benefits are at least as effective at supporting the lifetime poor."