BOSTON • Like thousands of American convenience stores, many 7-Eleven outlets cram rows of snacks between a wall of chilled sodas and a bank of churning Slurpee machines.

But starting this month, 7-Eleven will also begin selling cold-pressed juice that is organic, vegan, fair trade and gluten-free.

Analysts said the launch is a tiny part of a major trend sweeping truck stops, corner stores and mini-marts from coast to coast.

As sales of petrol, cigarettes and soda plummet, many stores are vying for consumers with fresh produce and other "better-for-you" products.

Mr Jeff Lenard, who heads strategic industry initiatives at the National Association of Convenience Stores, said nearly half of all convenience stores expanded their fruit and vegetable offerings last year.

7-Eleven, the world's largest convenience store chain, has aggressively developed products under the Go!Smart banner, pushing out low-sugar herbal teas, fruit-and-nut bars and rice crackers.

At Kwik Trip, a chain seen by many in the industry as the leader of the healthy stores movement, executives hired in-house dietitian Erica Flint to help introduce new products and reformulate old ones.

Each of the company's 586 stores now stocks fresh fruit and vegetables, from avocados and potatoes to mushrooms and "snack packs" of grape tomatoes.

Convenience stores also face a collapse of the industry's top-selling items - cigarettes, soda and petrol, said Mr Frank Beard, an analyst for GasBuddy, an app and data service for convenience stores.

Soda and cigarette sales have been down for years, he pointed out, and the margins on petrol are low. "Food sales are an opportunity for them," he said. "It's a perfect storm of factors."

This is not to say that convenience stores do not still sell junk food. Customers must often navigate a maze of chips and sodas, he acknowledged, to reach the raw almonds and bottled water.

And while chain stores have leveraged on their size and distribution networks to source healthy items, many independent stores have struggled to do the same.

Ms Melissa Laska, director of the Public Health Nutrition programme at the University of Minnesota, said: "They don't have access to the distribution chains that other stores have."

Despite those hurdles, she and other public health advocates continue to push for change in convenience stores. They are a top target since 93 per cent of the US population live within 10 minutes of one.

Convenience stores are often one of the only food sources in lowincome areas, where people may rely on them for groceries in between big trips to bigger stores or drop by regularly for snacks.

"People can't purchase healthier foods if they aren't available," Ms Laska said. "So this is the first step - but only the first step. Other things need to happen to change the wider food system."

For Mr Lenard, those next steps will involve getting more produce and other perishable foods to smaller stores. The industry is working on solutions, including cooperative buying arrangements and direct sales from farms.

Four of the country's largest convenience store distributors have committed to tie-ups with Partnership For A Healthier America, which is allied with former first lady Michelle Obama's Let's Move! project.

The companies have promised to make it easier for convenience stores to source produce and other healthy foods.

"Some stores may be slower to adapt," said Mr Beard. "But there's no question that everyone is going to follow."

WASHINGTON POST