The United States is known for trends like fat-free and gluten-free diets, but residents in Flint, Michigan are struggling with a much more serious concern: how to keep food lead-free.

For more than a year, the drinking water in this impoverished former manufacturing hub has been contaminated with lead, after water from the polluted Flint River caused pipes to become corroded.

Staying healthy amid the contamination has proven difficult, with simple, daily tasks like washing vegetables or rinsing a pot able to cause lead exposure.

The crisis, which was first ignored and then hushed up by government officials, is sure to be a key topic during a debate in Flint on Sunday between Democratic presidential hopefuls Hillary Clinton and Bernie Sanders.

- 'Afraid' -

In the contamination's wake, many Flint residents have been diagnosed with lead poisoning and more than 8,000 children have been reported exposed to lead, a harrowing statistic since it can irreversibly harm brain development.

Replacing all the corroded pipes could take years and residents are unsure when they can expect their water to be safe again.

Authorities are distributing vast quantities of bottled water, an operation that involves National Guard soldiers and hundreds of volunteers. They have also given away 108,000 water filters.

Most residents say they don't trust the filters, after being burned by authorities who had falsely assured the public that the drinking water was safe until the contamination was exposed by citizen activists.

"I am afraid of this water. I do everything with these bottles of water. I don't want to die," said Robert Cmejrek, a 72-year-old retiree.

Chia Morgan, a social worker and mother, said she uses about 10 bottles of water to cook a meal.

"You always have to go and make sure you have bottles of water in the house, it's no longer a pleasure."

Families are facing a logistical challenge to constantly buy, transport, store and then recycle all those plastic bottles.

Cafes and restaurants are also trying to reassure customers that their water is safe.

The cozy Cafe Rhema in downtown advertises on a sign that "Our water is filtered using reverse osmosis."

- Iron against lead -

Vendors at the nearby Flint Farmers Market are also quick to declare that their products are lead free.

Director Karianne Martus said the market and its vendors are recommending certain foods to residents who worried about lead poisoning.

A "nutrition and lead" cooking class is held in one corner of the large covered building, with recipes such as black bean and vegetable quesadillas, chocolate strawberry French toast, tuna melt and hearty egg burritos.

"Any foods that are high in iron, vitamin C, or calcium are really good in decreasing your lead absorption," said Joanna Sheill, the dietician who teaches the class.

Among the foods she recommends are fruits, vegetables, dairy, meat and dark green vegetables.