A gut health scientist easily eats 50 grams of fiber a day. Here's her breakfast, lunch, and dinner.

Dr.

Megan Rossi is a gut health scientist at King's College London and a registered dietitian.

The Gut Health Doctor Gut health scientist Megan Rossi eats at least 50 grams of fiber per day.

Fiber feeds the beneficial microbes that live in the gut microbiome and influence overall health.

To add an extra 10 grams of fiber a day, Rossi whips up a fruit and veggie smoothie.

Megan Rossi is serious about fiber.

The dietitian and gut health scientist based at King's College London estimates that she eats between 50 and 60 grams of the hearty stuff every day.

"It sounds like a lot, but our ancestors used to have 100 grams of fiber a day," Rossi told Business Insider.

Fiber is found in plant foods like fruits and veggies, whole grains, beans, nuts, and seeds.

It plays many crucial roles in the body, including feeding the trillions of "good" microbes living in the colon lining, which make up part of the gut microbiome and influence overall health.

" Fiber is beneficial because it doesn't feed the human part of us.

It feeds the bacterial part of us.

And when the bacteria eat the fiber, they produce all these amazing chemicals which help things like our mental health, keep our gut lining strong, regulate our appetite, our hormone balance ," Rossi said.

Although the dietary guideline in the UK, where Rossi lives, is 30 grams of fiber daily, she aims for 50 grams because evidence suggests this amount could improve mood, although more research is needed.