“This is a crazy diet,” Secretary of State Marco Rubio recently said, referring to Health Secretary Robert F. Kennedy Jr.’s sauerkraut-centric eating habits. “He has to travel with coolers of sauerkraut,” Rubio said.Kennedy is reportedly so obsessed with sauerkraut that he brings his own bag of the fermented cabbage to restaurants, travels with coolers of it and regularly pairs it with grass-fed meat. His wife, actress Cheryl Hines, said on a podcast last fall that Kennedy is so “dedicated” that he eats a steak and sauerkraut before 7 a.m. and often asks her to carry sauerkraut in her purse when they go out to eat. GettyRFK Jr. is reportedly so obsessed with sauerkraut that he brings his own bag of the fermented cabbage to restaurants.The eating pattern was introduced by Dr. Sean O’Mara, who advocates for grass-fed meat with fermented vegetables, like sauerkraut and kimchi. O’Mara refers to it as the Living Diet and says it can improve your gut health and metabolism, helping you lose weight and reduce the visceral fat that surrounds organs, according to The New York Times. Kennedy said he lost 20 pounds in 30 days eating this way. Rubio said the diet isn’t sustainable for him. But Commerce Secretary Howard Lutnick, Transportation Secretary Sean Duffy and Vice President JD Vance are embracing, The Wall Street Journal reports. But is eating this much sauerkraut healthy for everyone? Registered dietitians explain the health benefits and who should avoid fermented foods. The health benefits of sauerkrautSauerkraut is fermented cabbage that originated in China thousands of years ago to preserve the vegetable, and it’s often associated with Eastern European cuisine, according to the Cleveland Clinic. Fermented cabbage is popular in other cuisines, too, including kimchi in Korea and curtido in El Salvador. “Cabbage itself is rich in vitamin C, vitamin K and dietary fiber,” Sibylle Kranz, a registered dietitian and spokesperson for The Obesity Society, told HuffPost. “Fermentation can increase the bioavailability of some nutrients.” For example, fermentation can enhance certain B vitamins in sauerkraut, she said. Sauerkraut is also rich in potassium and beneficial plant compounds and low in calories, registered dietitian nutritionist Julie Pace, founder of Core Nutrition Health and Wellness, told HuffPost. One cup of sauerkraut contains 27 calories, according to the U.S. Department of Agriculture. It’s also a source of probiotics, or healthy live bacteria, as long as it’s raw and unpasteurized, Kranz said, adding, “Pasteurized, shelf-stable versions lose most of these live cultures.”Fermented foods have been shown to improve the gut microbiome, which supports digestive health. The new Dietary Guidelines for Americans state that fermented foods, like sauerkraut, kimchi, kefir, and miso, can support a diverse gut microbiome. Kranz added that fermentation can break down cabbage, making it easier to digest than when it’s raw. Research also suggests sauerkraut may benefit cardiovascular health. A recent study found that consuming sauerkraut (either raw or pasteurized) daily for four weeks led to a small reduction in systolic blood pressure. Sauerkraut may also support your immune system and help you lose weight. Is it healthy for everyone? And how much should one eat?There are no official serving guidelines for fermented foods, according to Stanford Medicine, which recommends a quarter cup per serving. Kranz suggested eating half a cup to a cup of sauerkraut each day, spread across your meals. “For most healthy people, there’s no reason they can’t enjoy sauerkraut every day as part of a balanced diet,” Pace said. However, some people should potentially avoid it, or at least talk to their doctors first, including: Anyone on a low-sodium diet.Salt is essential for fermentation, so sauerkraut is typically high in sodium, Kranz said. The exact amount of sodium depends on the brand or recipe, but it could contain 200 to 500 milligrams per half a cup, she said. The American Heart Association recommends a maximum of 2,300 milligrams of sodium per day, ideally 1,500 milligrams. picture alliance via Getty ImagesIt’s recommended to eat no more than 1/2 to 1 cup of sauerkraut per day.“High sodium foods can be particularly problematic for people who are managing high blood pressure or have heart or kidney conditions,” Pace said, explaining that too much sodium could contribute to fluid retention and make it more difficult to manage these conditions.People sensitive to histamine.Aged and fermented foods often have higher levels of histamine. Some people are sensitive to it, and others can’t break down histamine properly. As a result, eating sauerkraut or other fermented foods can trigger migraines, flushing, or digestive problems for them, Pace said. Individuals with gastrointestinal conditions. People with irritable bowel syndrome, small intestinal bacterial overgrowth (SIBO) or sensitive digestion should be cautious about eating sauerkraut. Pace said the fiber and fermentable carbs may cause gas, bloating, abdominal pain, or changes in bowel habits. Pregnant or immunocompromised individuals. Anyone who’s pregnant or immunocompromised should be cautious about consuming homemade or unpasteurized foods, like sauerkraut, Pace said. These items can become contaminated with microorganisms that may cause food poisoning or other illnesses. People taking certain medications. The vitamin K found in sauerkraut could interact with medications like the blood thinner warfarin, Kranz said. Sauerkraut also contains tyramine, an amino acid that helps manage blood pressure, and this could interact with the depression medication monoamine oxidase inhibitors (MAOIs) and cause an increase in blood pressure, Pace said. If you take these medications, talk to your doctor before eating fermented foods. How to add sauerkraut to your dietEating sauerkraut every day as part of a balanced diet is likely safe for most people, Pace said. But start small, such as a tablespoon to a quarter cup, if you’re not used to fermented foods, Kranz said, and progress to a half a cup to a cup a day. Keep in mind that “a sudden increase in fermented foods can cause gas, bloating or digestive discomfort while the gut adjusts, especially if the usual diet was low in high-fiber or probiotic-rich foods,” Kranz added. Also, check the amount of sodium in your sauerkraut and be careful not to consume too much salt, Pace said. “When buying sauerkraut, compare sodium levels, and look for a simple ingredient list, ideally cabbage, salt and spices,” she said. Sauerkraut with live cultures will be refrigerated and have terms like “raw,” “unpasteurized” or “live cultures” on the label.