Intermittent fasting is nothing new. People around the world have known for centuries that skipping some meals is good for the body.

A growing body of research is probing why fasting is so good for us.

Cancer researcher Dr. Miriam Merad just published a study showing that people who fasted for 19 hours in a day drastically reduced the number of circulating inflammatory cells in their blood. These cells accumulate in fat tissue and contribute to disease.

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When cancer researcher Dr. Miriam Merad came home from her laboratory with new results about how fasting might help reduce people's risk of developing certain deadly chronic diseases, her husband was so impressed that he stopped eating one meal a day.

She says he never eats breakfast anymore, limiting his eating hours to lunch and dinnertime.

She, too, has started moving her dinnertime to earlier in the evening.

"Indeed, you feel better if you have time to digest," Merad said.

The household shifts in Merad's eating hours come on the heels of her latest research, a small but novel study published in the journal Cell on Thursday that showed fasting can have positive benefits on a cellular level for otherwise healthy people.

Intermittent fasting helps prevent inflammation in the body

By examining the blood of 12 healthy adults who'd fasted for 19 hours, Merad and her co-authors found that a break from regular eating helped put people's inflammatory monocyte cells at rest. These cells, which are dispatched to heal wounds and prevent infection, also accumulate in fat tissue and contribute to chronic diseases like diabetes and heart disease.

In other words, Merad is starting to think that skipping some meals could help people live longer, healthier lives.

Read More: Skipping a few meals with intermittent fasting may help people avoid cancer, diabetes, and heart disease

Some of her research partners are now trying out a meal-skipping strategy, too.

"Many of the people in my lab are starting to do this intermittent fasting," she said.

Her lab partners are not alone. Celebrities including Terry Crews, Hugh Jackman, Kourtney Kardashian and Jack Dorsey all swear by their own intermittent fasting plans, which limit the number of hours reserved for eating in a day, or (in more extreme cases) in a week.

"My first meal is at 2 p.m.," Crews previously told Business Insider. "And then I eat from 2 to 10."

Terry Crews. REUTERS/Brendan McDermid

Evidence suggests fasting is good for our hearts and guts

People have been experimenting with periods of deprivation, either for religious or cultural reasons, for thousands of years. Lab research, though scant, suggests that people who fast or restrict calories may have fewer heart issues, better cholesterol levels, lower stroke risk, and fewer instances of diabetes.

The science of intermittent fasting for weight loss, however, is far from settled. Merad cautions that anyone who wants to attempt a new fasting routine should consult a doctor and nutritionist before they start.

"I'm not saying food is our enemy, absolutely not, we need to eat otherwise we die," she said. "But it is true that we probably eat too much ... we eat too often."

Fasting can still be dangerous, and not everyone should try it

Not everyone should fast. People with a history of eating disorders or diabetes, as well as those who are pregnant, should be especially wary of skipping meals.

But even for people who have no reason to avoid fasting, the practice can be a bit of a catch-22. While eating puts extra stress on the gut, not eating for extended periods of time requires a lot of willpower (something us humans are notoriously terrible at harnessing), and might result in bingeing, releasing stress hormones, too.

Some nutrition experts don't support the practice at all.

"We all have a natural overnight fast when we sleep," New York City-based dietitian Alissa Rumsey recently told Business Insider. "I typically don't recommend any type of specific fasting outside of that because really what you're doing is overriding your body's intuition."

Still, there is some consensus in the new fasting research. Even nutrition experts who don't support fasting tend to agree with Merad that sugar is one of the most toxic foods for the human body. We have clear evidence that too much sugary food contributes to all kinds of chronic diseases, including diabetes and heart disease.

In this new study, monocyte cells were most excited when people ate especially sugary diets, providing even more evidence that too much sugar is dangerous for people.

"I would encourage everyone to revisit this snacking thing, like is there a way we can eat differently?" Merad said. "Maybe eating two times a day would be entirely sufficient and very beneficial, in fact, in terms of health."