It might not just be your waistline that thins if you embark on an intermittent fast. Those lost pounds might take a few hairs with them.

That’s what Chinese scientists suggest in a new study. They report that this style of fasting significantly delays hair regeneration.

Intermittent fasting comes in several flavors. It can involve eating normally during a specific time window, say 10 a.m. through 6 p.m., but then fasting the rest of the day. Some subscribe to alternate day fasting — eating normally on one day, then eating nothing or very little the next.

In the hair study, scientists put 49 young adults on a strict 18-hour daily fast that reduced hair growth by 18%. A separate experiment that involved mice fasting 16 hours a day demonstrated significantly delayed hair regeneration.

The mice who ate normally took just 30 days to regrow lost hair. The dieting mice took 96. But mice have a higher metabolism than humans. So, the impact of fasting is less pronounced in people.

So, what’s going on?

Well, blame it on hair follicle stem cells that fail to adapt to the metabolic upset of fasting. When fasting, our cells tap fat for energy instead of glucose. In doing so, they can be overwhelmed by oxidative stress, causing hair cells to self-destruct.

Some remedies, however, appear to help. For example, topical vitamin E can heighten antioxidant capacity that helps shield hair cells during fasting.

Researchers are quick to point out that they don’t want to scare people from trying intermittent fasting. The benefits, they say, can have a positive impact on health.

Just know that it could have a hairy side effect.