The preliminary budget proposal released by the Trump White House on Thursday calls for cuts to a program aimed at improving nutrition among low-income women and children, potentially placing some of its key programs in jeopardy. The cuts proposed are similar to those sought in recent years by House Republicans as they targeted social welfare programs for federal savings.

Trump’s budget proposes to cut the Special Supplemental Nutrition Program for Women, Infants, and Children, known as WIC, from $6.4bn to $6.2bn. The program, which is aimed at reducing infant and maternal mortality and morbidity, provides food vouchers for low-income pregnant women, nursing mothers, and children under five years old, as well as breastfeeding support and nutrition education.

The cuts are probably not significant enough to threaten WIC’s ability to provide vouchers for its current caseload, according to the National WIC Association. But it could impede WIC’s ability to provide local education programming and breastfeeding support, or administer its existing programs.

More than 7.8 million women and children participated in WIC in the first three months of the 2016 fiscal year. Children and infants usually make up three-quarters of WIC recipients.

The program is already troubled. WIC differs from other forms of welfare in that not everyone who is eligible for WIC assistance is guaranteed to receive it. In 2013, the program served about half of all infants born in the US, but only 83% of eligible infants. Congress’s inability to pass a budget that year also forced many WIC field offices to close. Families with children or pregnant mothers living at or below 185% of the federal poverty line are generally eligible for the program.

From 2010 to 2016, according to preliminary numbers from December last year, the number of people enrolled in WIC declined by nearly 2 million.

Research suggests that WIC may have had a hand in eradicating some food deserts – neighborhoods with little or no access to fresh or healthy foods – and causing the rate of early childhood obesity to go into freefall. Beginning in 2009, the program, which dates to the 1970s, began providing vouchers for fresh produce and permitted the purchase of whole grains and baby food.

A group of Yale University researchers observed 300 Connecticut grocery stores before and after the change in policy and found that many began to carry more whole wheat products and fruits and vegetables.

That change has also been linked to a steady decline in the calorie consumption of households with children. In 2013, health officials in 18 states said the obesity rate had decreased for WIC-enrolled preschoolers.

It is only recently that WIC has become a target of conservatives seeking to slash government funding. In the 1990s and 2000s, WIC for the most part enjoyed bipartisan support. But House Republicans have been seeking to slash WIC since 2012, when they proposed cuts of $243m. Democrats in the Senate blocked those cuts.