Giving rats a special vitamin-like supplement called nicotinamide riboside every day for 12 weeks seemed to help them gain less belly fat, even when eating fatty food.

What we've found so far suggests that nicotinamide riboside may be linked to reduced fat gain in rats eating a high-fat diet. Our analysis of the available research shows this effect has been observed in studies we’ve reviewed. We analyzed 45.0 research assertions and found all of them support the idea that giving nicotinamide riboside to rats on a high-fat diet is associated with less belly fat gain over 12 weeks [1]. No studies in our review refuted this observation. The evidence we’ve reviewed consistently points in one direction: rats receiving this supplement tended to accumulate less fat, especially in the abdominal area, even when their diet was high in fat. Nicotinamide riboside is a form of vitamin B3 that plays a role in cellular energy production. While we don’t yet know exactly how it might influence fat storage in rats, the pattern across the studies we’ve examined is clear—supplementation was linked with lower fat gain in this context [1]. That said, our current analysis is based only on animal research, and all the data come from studies involving rats. We cannot assume these results apply to humans or even to other animal species. Also, while the evidence leans toward a consistent effect in rats, we’re still building our understanding of the conditions, dosages, and long-term impacts. The takeaway: in rats, daily nicotinamide riboside over 12 weeks has been associated with less belly fat gain, even when eating fatty food. This is what we’ve found so far—but science keeps evolving, and so will our analysis.