Following a ketogenic diet — one that's low in carbohydrates and rich in fat — for six months significantly reduced measures of body fat and fatigue, eased disease symptoms, and improved exercise capacity, cognition, and arm and hand dexterity in people with relapsing-remitting multiple sclerosis (RRMS), a study showed. Moreover, some of these benefits were sustained for at least three months after the study’s completion, though several measures worsened during that roughly 12-week period, mostly due to difficulties in maintaining a strict ketogenic diet in the real world, according to researchers. While most patients demonstrated interest in following the diet after the trial ended, only 58% did so, the data showed. People who experienced greater reductions in body mass index or BMI — a ratio of weight to height — and fatigue more often maintained the dietary plan. "This post-trial observational study provides evidence that [ketogenic diets] are sustainable diets (in the short-term) outside of the clinical trial setting," the researchers wrote, though stressing that "longer-term dietary intervention and observation studies are essential." The study, “Ketogenic diet in relapsing multiple sclerosis: Patient perceptions, post-trial diet adherence & outcomes,” was published in the journal Clinical Nutrition. Investigating the long-term impact of a ketogenic diet for MS. The so-called ketogenic diet, originally developed as a way to manage certain seizure-causing disorders, consists of eating minimal amounts of carbohydrates, moderate protein, and high quantities of fat. The goal is to mimic a fasting state, leading the body to use fats as its main energy source — a process called ketosis. A few small studies have indicated that following a ketogenic, or keto, diet may help to ease fatigue and depression, and improve quality of life in people with MS. But the diet may also have some negative effects, like vitamin deficiencies, high fat levels, and kidney problems. To better understand the tolerability and clinical efficacy of a keto diet in certain types of multiple sclerosis (MS), researchers in the U.S. conducted a Phase 2 clinical trial (NCT03718247) that began in 2018 and ran through 2021. It enrolled 64 RRMS patients, all of whom followed the diet for six months. Results published last year showed that patients saw significant reductions in weight, fatigue, and depression, better exercise capacity, improved dexterity, and a higher physical and mental quality of life. However, the long-terms effects of a ketogenic diet for MS outside of a clinical setting remained largely unknown. Thus, researchers analyzed the perspectives of a group of RRMS patients who followed the diet over the six months — as well as dietary changes and outcomes three months after the trial's completion. Most patients experience fewer MS-related symptoms on ketogenic diet. From the initial pool of 64 patients, 89% — 57 individuals — completed the study’s half year of a ketogenic diet. After the six months, 27 patients reported an easing in their MS-related symptoms, with reductions of prickling sensation and pain for 41%, lessening of numbness in 15%, and improvement in balance for 15%. Also, reductions were seen in the frequency of severe headaches (by 15%), in urinary urgency (by 7%), and in muscle spasms (by 4%). Vision improvements were reported by 4% of patients. Most patients reported they would continue following the keto diet, either exactly as in the trial (44%) or following a less rigorous carbohydrate restriction (47%). Five patients (9%) said they would not continue the dietary regimen. Almost all patients (93%) said they would recommend the ketogenic diet to their friends with MS "without reservation," according to researchers. The participants also were willing to join a future trial testing a ketogenic diet for a median of 12 months (range 1-60 months, or five years). Weight loss was reported as a the main benefit of the ketogenic diet by 62.5% of the patients. More energy and focus (28.5%), improved health (5%) and sleep (2%), and fewer headaches (2%) also were reported. The most challenging aspects of following a ketogenic diet included avoidance of typical foods or ingredients (44%), difficulties in adhering to a ketogenic diet when eating out (31.5%), and difficulty increasing overall fat intake (14%). Doing the keto diet alone (5%), lower energy (3.5%), and the need for daily urine ketone checks (2%) also were reported as challenges. The ketogenic diet was deemed more costly than the diet outside of the study by 63% of participants, who reported a median cost increase of $100 per month. The other 37% of patients considered it similar or even cheaper than their previous diets, particularly considering the costs saved from eating out less frequently. During the trial, 23% of patients stopped or reduced their use of medications for fatigue/attention, muscle stiffness/nerve pain, diabetes, and prevention of migraines. Only five patients (9%) started or increased the use of certain medications during the study. Less than 60% of RRMS patients stuck to ketogenic diet after study's end. A total of 52 patients (81%) returned and completed the three month post-intervention assessment. The majority continued adhering to a ketogenic diet — 21% followed the same dietary plan used in the study and 36.5% opted for a less strict regimen. A total of 23% went back to their pre-study diet; the remaining transitioned to what they deemed a more balanced diet or to another special diet. "We show that despite a high [participant] interest in continuing with a KD [ketogenic diet] at the end of a structured, 6-month intervention trial (91% of subjects), there is expected attrition of subjects who continue to adhere to a KD in the real world (58% of subjects) outside of study parameters," the team wrote. Those with greater reductions in BMI and fatigue during the study were more likely to continue the diet following trial completion. Patients who opted to stop the ketogenic diet were asked about the most frequent changes they noticed when no longer following the eating plan. A lack of sustained weight loss was reported by 62%, and on-diet fatigue reduction by 49%. Worse concentration (30%), anxiety (25%), MS symptoms (23%), and sleep (23%), among others, also were reported by individuals who stopped the keto diet. Overall, after the trial’s completion, patients continued to exhibit significant improvements in several parameters, albeit to a lesser extent. Lab work showed that vitamin D levels remained significantly higher and the hemoglobin A1c — a measure of blood sugar over the past three months — remained reduced. The levels of circulating fats, including cholesterol, also remained significant reduced. "Regardless of diet type following trial completion, the 6-month KD intervention did appear to produce sustained dietary changes in study [participants] in the 3-months following KD intervention," the team wrote. However, they noted that “the intervention and follow-up phase of this research is relatively short," with further studies needed on longer-term effects.