Megyn Kelly Reveals She's Trying New Diet Followed by JD Vance and RFK Jr.

Megyn Kelly tried a meat-and-fermented-foods diet that, she said, Vice President JD Vance and Health and Human Services Secretary Robert F. Kennedy Jr. have followed. She also gave the doctor who designed it, Dr. Sean O'Mara, a long interview to make his case to her audience.

The interview is not new. It ran again in a health-themed Sunday compilation of The Megyn Kelly Show, which Kelly introduced as "three of our recent deep dives." The conversation itself was recorded sometime after late March 2026. Kelly said Vance had started the diet for Lent and showed photos of him taken "February 28th to March 27th," and O'Mara referred to "today, 2026." The compilation did not say when the segment first aired.

Kelly said she first heard that Kennedy was on the diet. "And then one thing led to another and I found out JD Vance was on this diet too," she said. She added that The Wall Street Journal "did a piece on it and said that Sean Duffy, the transportation secretary was on this diet," and, she said, the Journal's report also named Commerce Secretary Howard Lutnick.

Who in the Trump Administration Has Followed the Diet

In an interview with Katie Miller that Kelly played on the show, Kennedy's wife, the actress Cheryl Hines, described his routine: "Well right now he is only eating meat and fermented vegetables." She said he "will bring his own sauerkraut to a restaurant."

What is known about Vance's diet comes from Kelly, not from Vance himself. She said on air: "His name is JD Vance and he started it for Lent." Kelly then showed the late-February and late-March photos of the vice president and told viewers, "You can see how much less puffy he is."

O'Mara said "senators and congressmen, politicians have been finding out about this. And so I work with quite a few of them now." He did not name any of them.

Megyn Kelly's MRI and a Day and a Quarter In

Kelly said her staff booked her a full-body MRI before the interview. O'Mara read the scan for visceral fat, the fat that surrounds the organs, and Kelly said, "let's just say I didn't get an A." At the time of the recording, she said, "I am a day and a quarter into the Sean O'Mara diet."

She described her first full day on the plan. Breakfast was eggs, a little kefir, a couple of small strips of steak and a little cheese of the smelly, old-world kind the diet allows, such as blue cheese, gorgonzola or Roquefort. Lunch was steak with several ferments, and dinner was the same again.

Kelly noted that her father died of a heart attack at 45. She said she planned to see her cardiologist about three months into the diet to check for arterial buildup, and to repeat the MRI. She told listeners: "Check with your doctor before you jump full in." She also said, "I'm actually excited to try it."

How Sean O'Mara's Claims Compare With Federal Guidelines

Parts of O'Mara's approach match federal advice. The 2025–2030 Dietary Guidelines for Americans, released in January, recommend fermented foods such as kimchi and miso for gut health and tell Americans to limit highly processed food. The same guidelines still include fruit and whole grains and cap saturated fat at 10 percent of daily calories.

O'Mara goes much further. He tells clients to eat fruit only when it is fermented, and he said of sourdough bread, "It is very bad for you, it's just not as bad." He called LDL cholesterol the wrong thing to watch. That contradicts a 2017 European Atherosclerosis Society consensus statement, which found that genetic, epidemiologic and clinical studies "unequivocally" establish that LDL causes atherosclerotic cardiovascular disease.

O'Mara also showed photos of Joe Biden and Donald Trump from 2020 and 2024. He admitted, "we don't have the benefit of MRIs to see what happened," and put the changes in their faces down to cortisol and inflammation. Of Trump, he said he believed one of the president's sons had "gone carnivore" and might be influencing his father. He did not say Trump was on his diet.