(FOX BUSINESS) -- Back to school is fueling online grocery sales.

Online grocery delivery service FreshDirect reported a 46% year-over-year sales gain for Labor Day week as schools began to open up after the holiday, Supermarket News reported.

Among the most in-demand items have been frozen foods, which also saw a spike in popularity when pandemic lockdowns first went into effect in March. Sales of frozen pizzas and burritos surged 100% year-over-year, according to the report. On-the-go food items have also increased in interest.

Fresh foods like ground turkey and plant-based items have seen a spike of 80% in online grocery orders, perhaps as consumers aim to provide healthy family meals after many relied on processed canned goods and shelf-stable items during the nationwide lockdowns.

While many schools have reopened for in-person learning, a number of parts around the country are still holding virtual classrooms, which have placed an added expense for families who relied on free lunch programs for their children.

Around 30 million children received meals from their schools’ breakfast and lunch programs, according to the School Nutrition Association, and now one in four parents say providing breakfast and lunch for their kids at home has resulted in debt taken on during at-home learning, according to an August survey from finance company Credit Karma.

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