A few months ago, in a conference room at the Yard, a co-working space in Manhattan, a group of female employees were updating their boss, Alisa Vitti, on their latest projects and the state of their hormones.

“I’m in my luteal phase right now, so very into organization,” said one woman, citing the second phase of her menstrual cycle as explanation for the series of perfectly structured charts she was presenting on a screen at the front of the room.

Ms. Vitti, 42, the founder of Flo Living, a lifestyle company focused on female health and nutrition, listened as she drank water and herbal tea. She has been caffeine-, dairy-, gluten- and sugar-free for 20 years, and maintains that the shift helped cure her of the polycystic ovary syndrome (PCOS) she struggled with since she was a teenager.

That recovery has also informed her professional mission — to spread a gospel of dietary and lifestyle changes that may help women dealing with complex and confounding hormonal issues, usually related to their periods.

There are some tips that Ms. Vitti dispenses somewhat universally: Eat fermented foods like kimchi and sauerkraut to help support your microbiome; avoid consuming large quantities of sugar; and eliminate dairy, which she sees as a root cause for issues like PCOS, acne and endometriosis.

Ms. Vitti does not have a medical degree. After studying for two years at the Integrative Institute of Nutrition, a licensed vocation school, she quit a job in marketing and apprenticed for a few years with alternative medicine practitioners. In 2000, she started her own walk-in clinic in Manhattan. By 2010, she said she was seeing around six patients every day, often during after-work hours, and receiving hundreds of emails from women in Europe and India seeking her advice. That year, she closed the clinic to focus on expanding the practice into a digital brand.

Dr. Elizabeth Fino, a reproductive endocrinologist and infertility specialist at the New York University Langone Fertility Center who is familiar with Ms. Vitti’s work, agrees that diet and lifestyle shifts should be the first line of treatment for women facing hormonal issues like PCOS. But she also believes that modern medical treatment — for example, taking birth control to regularize periods — is often the best and most realistic option. (Ms. Vitti is pro birth control in general, but does not encourage it as a treatment for existing hormonal imbalances.)

“Her approach takes significant dedication on the patient’s part, and it’s just not attainable for a lot of people,” said Dr. Fino, noting how expensive and time consuming it can be to follow a clean eating regimen. Ms. Vitti’s supplement kit, for example, which includes a 60-day supply of five different supplements including fish oil and magnesium, costs $215. That’s about $1,200 a year.

The language Ms. Vitti’s employees use is pulled from “WomanCode,” a book she published in 2013. Referred to by fans as “the purple period bible,” the book offers women alternative strategies for dealing with tough hormonal issues, including endometriosis and cystic acne.

Its treatment suggestions are meant to replace medicines like spironolactone and ibuprofen that many gynecologists rely on for symptom management. The approach is grounded in a concept of “cycle-syncing,” or catering one’s diet, exercise and lifestyle habits to the four phases of the menstrual cycle (luteal, menstrual, follicular and ovulatory).

Within each menstrual phase, women’s hormones shift, causing energy levels and dietary needs to shift as well, Ms. Vitti said. During the luteal phase, for example, “WomanCode” recommends that women eat roasted vegetables to stave off increased sugar cravings, and increase their intake of leafy greens to ward off bloating.

Unlike during the follicular and ovulatory phases, when Ms. Vitti said women have the most energy, exercise during the luteal phase should be less intensive — think gentle yoga or light weights.

For Nashira Arno, a 30-year-old jewelry designer in Brooklyn, discovering “WomanCode” gave her hope.

“I’ve had a horrible period — not a bad period, a horrible period — since I was 13,” said Ms. Arno, who grew up in the Dominican Republic. As a teenager, she would have to go to the emergency room because of the severity of her cramps.

She received no diagnosis, she said, and a stream of heavy-duty painkillers that didn’t solve the problem. Eventually, she felt even worse. By the time she came across “WomanCode” at age 29, she had written off doctors altogether.

Once she made the dietary shifts recommended by Ms. Vitti, she said, her cramps went from a pain level of 20 to 5, her once acne-prone skin cleared up, and she had fewer digestion issues.

“I’ve always been healthy-ish, but now I look at food as medicine,” said Ms. Arno, who takes supplements recommended by Ms. Vitti, including vitamin B6 and magnesium.

“WomanCode” is part of the larger Flo Living brand, which includes a digital clinic, a period tracking app and hormonal supplements. The company’s “Monthly Flo Program,” which costs $297, provides educational videos. Thousands of women have signed up for one or all of these offerings.

“I think most people today understand that there’s a clear overlap between your diet and lifestyle and how these things impact you medically,” Ms. Vitti said.

But many of these changes can be prohibitive. Even for those women who can afford to maintain the protocol laid out in “WomanCode,” some find the guidelines too complex to follow every day.

“It’s a lot, and that’s coming from me, a person who takes 500 different, obscure vitamins every morning,” said Ariana Cleo, a 26-year-old founder of a wellness public relations firm.

A few years ago, Ms. Cleo took a fertility test and was told by a doctor that she had diminished ovarian reserves. She is now using Ms. Vitti’s period tracking app to monitor her hormones while also eating more food — specifically more carbs and protein — which is all in line with the Flo Protocol. When she feels the need to rest, she is trying to honor that, instead of pushing through a SoulCycle class like she would have in the past. “Alisa’s teachings are all about tapping into our feminine energy — being intuitive, compassionate and empathetic towards our bodies — and resisting the masculine drive to succeed at all costs and just go, go, go,” she said.

There are some who have serious reservations about the approach. Dr. Jennifer Conti, an adjunct clinical professor at Stanford University School of Medicine, wrote in an email that the fixation on so-called hormone imbalances may be “on-trend,” but “in reality, hormones are necessary, fluctuating chemicals our body needs for a variety of everyday functions.”

Women who have a condition like PCOS, she said, should “talk with their gynecologist about creating a shared decision-making goal for management.”

Still, many women feel supported by Ms. Vitti’s approach. After Nicole Gulotta, 37, of Raleigh, N.C., struggled to get pregnant and then suffered a miscarriage in 2013, she followed the Flo Protocol for a year. She became pregnant and gave birth to a boy in October 2015.

To her, there was a clear connection. “The program helped me uncover the root cause of my symptoms and also release some emotional blockages that were holding me back,” Ms. Gulotta said.