Carnival Slashes Food Waste and Saves Millions

Anyone who has vacationed on a cruise ship knows that the amount of food prepared by onboard chefs and kitchen staff can seem mind-boggling, considering the vast buffet areas, huge dining rooms, and variety of specialty venues.

Many have likely wondered: How do they know how much food to prepare and what happens to all of the leftover food? 

Thanks to an ambitious multi-pronged effort, Carnival Corporation announced on June 10, 2025, that it has exceeded its own goal to substantially reduce food waste across its global cruise brands as part of its “Less Left Over” policy.

The conglomerate that operates major cruise lines, including Carnival Cruise Line, Princess Cruises, Cunard, Holland America Line, and Seabourn, among others, vowed a 40% cut in food waste by 2025 but actually realized a reduction of 44% in 2024 compared to 2019.

Who knew, for example, that the company was turning used cooking oil into a biofuel for its excursion tour buses in Alaska, or that used coffee grounds are being up-cycled into vegan soap?

Those are innovative projects, for sure, but the company and its cruise brands are utilizing multiple onboard programs to cut down on waste and make sure that prepared meal portions are “just right.”

So far, the company has dodged paying some $250 million in the cost of food it estimates it would have spent without the “Less Left Over” initiative. Going forward, more gains are expected in the next five years.

“Our Less Left Over strategy is powered by dozens of large and small programs and technologies across our cruise lines to cut food waste by 50% by 2030,” said Josh Weinstein, CEO of Carnival Corporation. 

“But more than that, it’s also a global rallying cry that is turning everyday actions into lasting impact by nurturing a shared mindset among our 160,000 talented team members – a mindset that values creativity in delivering amazing meals for our guests and crew while getting the most out of our resources,” added Weinstein.

That mindset comes from using real-time data and AI systems to track dining patterns, cutting food waste in the ways that meals are plated, training staff in precision techniques when provisioning and preparing ingredients, and serving what the company calls “just right” portion sizes.

Also, the cruise brands donate extra meals and ingredients to food bank networks in destinations where food scarcity is a problem.

Biodigesters Help Lines Dispose of Leftover Foods

No matter how hard the cruise brands try to get portions just right and order only the precise amount of food believed necessary for any particular voyage, there will always be leftover food. That’s why Carnival Corporation began installing hundreds of so-called biodigesters on its ships three years ago.

By the end of 2024, it had 630 biodigesters installed across the brands. They are known as metallic stomachs, with technology that enables natural bacteria to liquify leftover foods, making them easier to discard.

The California-based company Power Knot Ocean provided the biodigesters to Carnival; its most recent investment came in 2024, when the company received orders for additional machines plus spare parts and other related services.

The Carnival brands also have more than 90 dehydrators and dryers that remove excess water from more challenging food items, reducing so-called hard waste by about 90%. The leftover dried material can eventually be used as organic mulch and compost.