Tired of Thanksgiving weight gain? Next year you might want to pass on the sweet potato pie and drink a tall glass of sweet potato wastewater instead.

That’s what a new study in the Heliyon journal hints at with what Modern Farmer says “might be the weirdest weight-loss discovery of the year.” Scientists in Japan had been brainstorming on what to do with all of the wastewater left over after people had boiled or steamed their sweet potatoes.

They fed the starch-heavy water to mice and were surprised to find that the rodents ended up losing weight, as well as experiencing lowering liver mass and cholesterol and triglyceride levels.

The apparent cause: the sweet potato peptide (SPP) created by enzyme digestion of proteins in the wastewater, per a press release. The mice in the experiment were split into three groups, all given high-fat diets, but with only two of the groups also fed SPP (one group received a low concentration, the other a higher one).

After 28 days, mice who took in the SPP enjoyed “significantly lower body weight and liver mass,” and their cholesterol and triglyceride numbers dropped. The study indicates that SPP may set off hormones in mice that reduce hunger; it may also help control lipid metabolism.

More research is needed to see if the findings also apply to humans, but lead scientist Dr. Koji Ishiguro calls it “promising” in the release, saying SPP may offer “new options for using this wastewater instead of discarding it.” (Another type of potato is used for …contraception?)