FRESNO, Calif. (KFSN) -- New restrictions on the federal food stamp program could slash benefits for 688,000 people, according to the US Department of Agriculture.About a fourth of the households in Fresno alone receive food stamps through Cal Fresh or SNAP, the Supplemental Nutrition Assistance Program.Families with children would not be affected by the new rule.But as many as 18,000 people in Fresno County will lose their benefits.A Valley-wide breakdown on how many local food stamp recipients might be affected by SNAP reform has not yet been determined.Still, Central California Food Bank CEO Andy Souza expects to see a severe impact in some pockets of the Valley next year."It's a bit of a shockwave. It's a little disconcerting to families and individuals who are mostly affected by this. But at the same time, we've got to get our hands around this and figure out where those pockets of need are," said Souza.The Trump administration believes with a stronger economy, assistance to unemployed adults is not necessary in a strong job market.LA Mayor Eric Garcetti says tens of thousands of people will be affected."I find it absolutely unconscionable that we would have an administration in Washington, at a moment when so many Americans are still suffering, that we would literally take away the ability to feed their children," he said.The food stamp rule change will impact childless adults between 18 and 49 who are not disabled."We're talking about adults who are in transition. Getting back into the workforce. We're talking about adults who may be veterans transitioning back into the workplace," said Souza.Those impacted will need to work at least 20 hours a week, for more than three months to qualify for SNAP, though they can get waivers in some states with high unemployment.The new restrictions on food stamps take effect in April.