But a new study from researchers at the University of Michigan finds that that may not be the case—and serves as a reminder that figuring out what is and what is not bad for the environment is more complicated than it seems.

Meal kit services, from companies including Blue Apron and Plated, send pre-portioned raw ingredients along with recipes. They’re pitched as a way to avoid grocery shopping, spice up your kitchen routine, and provide a home-cooked meal without the stress of, well, planning a home-cooked meal. But those pre-portioned ingredients are often wrapped in plastic, insulated with styrofoam, and chilled with cooling packets, prompting environmental criticism.

The new study traces food in meal kits from farm to table, and actually found that meal kits—they used Blue Apron, though the company did not provide funding for the study—clock in at using a third less greenhouse gas emissions than shopping at the grocery store. How is that possible?

One of the chief benefits of meal kits, and one touted by the companies selling them, is a reduction in food waste: the kits only provide what you’ll need for that recipe, and no more. That has a substantial impact on reducing emissions. But there’s also a lot of transportation stuff involved. Meal kits bypass the entire need for a grocery store—those are pretty bad for emissions—and also, because they’re delivered on trucks along with other mail, eliminate the need for shoppers using personal cars to drive to the store.

It’s worth noting that this study compares meal kits to shopping at traditional supermarkets, rather than, say, farmers markets. It also doesn’t address the fact that meal kit companies are failing at an alarming rate; MarketWatch calls the entire business model “unsustainable.” But the study does serve as a reminder that more goes into your food—including environmental resources—than we might realize at first glance.