![\"New](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2026\/04\/21140625\/SEI_294031830.jpg\")
<\/div>In February,\u00a0Robert F.\u00a0Kennedy Jr., the US secretary of health,\u00a0made a\u00a0characteristically\u00a0bold claim.\u00a0A doctor\u00a0at\u00a0Harvard University,\u00a0he\u00a0proclaimed,\u00a0\u201chas cured schizophrenia using keto diets\u201d.<\/p>\n
If you happened to be passing Harvard University that day, you might have heard the sound of that doctor\u2019s palm hitting his forehead. \u201cFor the record, I have never ever once used the word \u2018cure\u2019\u202fin any of my work,\u201d says Christopher Palmer, a psychiatrist at Harvard Medical School. \u201cNonetheless, I have<\/em>\u00a0used the word\u00a0\u2018remission\u2019\u2026\u201d<\/p>\n The idea that a diet best known as a fat-busting fad could treat serious mental illness might sound like the latest offering from the wild west of online wellness: something destined to be filed alongside raw water\u00a0and coffee enemas\u00a0in the annals of terrible\u00a0suggestions.<\/p>\n But\u00a0there are\u00a0a number of\u00a0reasons why\u00a0the idea of\u00a0using\u00a0the\u00a0diet\u00a0for\u00a0conditions affecting\u00a0the brain\u00a0deserves\u00a0closer inspection.\u00a0For\u00a0one thing,\u00a0over\u00a0100\u00a0years\u2019 worth of\u00a0research has shown\u00a0that ketogenic diets\u00a0have real, measurable effects on\u00a0the body\u00a0in general, as well as on the organ between your ears.\u00a0For another,\u00a0many of\u00a0these changes\u00a0\u2013\u00a0some at the cellular level, others throughout the whole body\u00a0\u2013\u00a0are\u00a0known\u00a0treatment targets\u00a0in mental illness.<\/p>\n With evidence from small trials and case studies indicating that ketogenic diets can dramatically improve symptoms in some people with mental health conditions, a growing number of scientists are wondering if what is called metabolic psychiatry could lead to much-needed new treatments for conditions affecting the brain and the mind-body connection.<\/p>\n <\/p>\n \u201cWe\u2019ve wasted 30 years thinking about dopamine and serotonin as the sole targets for psychiatric medications,\u201d says\u00a0Daniel Smith,\u00a0a psychiatrist at the University of Edinburgh, UK.\u00a0\u201cThis is\u00a0a new paradigm.\u00a0It\u2019s\u00a0exciting.\u201d<\/p>\n Nowadays, ketogenic diets are mainly associated with efforts to lose weight, but they were first developed more than a century ago to treat problems with the brain. At that time, few drugs were available for epilepsy. One thing that did seem to work was fasting for several days at a time, which significantly reduced seizures and sometimes stopped them altogether. The problem was, it wasn\u2019t sustainable. Sooner or later, people would need to eat and when they did, their seizures would return.<\/p>\n Researchers set out to find a solution,\u00a0and in\u00a0the\u00a01920s,\u00a0Russell Wilder, a physician and epilepsy researcher at the Mayo Clinic in Minnesota, cracked it. He developed a high-fat, moderate-protein and very-low-carb diet to mimic fasting, while still providing enough energy to live on. He called it the ketogenic diet because it was designed to trigger the metabolic shift that happens when the body cannot get hold of carbohydrates from food and so has to switch to burning fats, generating small molecules called ketone bodies in the process.<\/p>\n As we are a species that mostly eats plants, carbohydrates are our default fuel. Carbs are quickly broken down into glucose during digestion, which can be burned in our cells for energy. This process takes place in the mitochondria, cellular organelles where food is converted into adenosine triphosphate (ATP), the body\u2019s energy currency. What isn\u2019t used straight away is stored as glycogen in the liver and muscles, to be called on between meals. When those stores are full, any spare calories are deposited as fat.<\/p>\n If food is short, and carbohydrates\u00a0aren\u2019t\u00a0so easy to come by, the body\u00a0reverses the process.\u00a0First\u00a0it\u00a0releases stored glycogen, which can keep us ticking over for up to a day. When that runs out, the body\u00a0begins\u00a0to break\u00a0into its\u00a0fat reserves\u00a0for energy.<\/p>\n Some of the fatty acids\u00a0released\u00a0are\u00a0sent to be\u00a0burned in the mitochondria, while others are\u00a0passed\u00a0to the liver,\u00a0where they are\u00a0converted into ketone bodies.\u00a0Ketone bodies are smaller\u00a0than fatty acids\u00a0and, because they are water-soluble, are\u00a0easier to transport in the blood\u00a0to where they are needed.\u00a0They also\u00a0have the advantage of being small enough to cross the blood-brain barrier,\u00a0allowing them to be\u00a0used in place of glucose as\u00a0fuel for the brain.<\/p>\n The keto diet is high-fat, moderate-protein and low-carb \u2013 making foods like eggs, meat, avocado and leafy greens typical fare<\/p>\n Addictive Stock\/StockFood<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n It is an ingenious system, and the switch back and forth between fuel types probably came into play pretty regularly for our hunter-gatherer ancestors. For most modern humans, though, carbs are so easy to come by that the metabolic switch happens rarely, if at all.<\/p>\n Wilder\u2019s idea was for a\u00a0diet\u00a0designed to\u00a0flick\u00a0the\u00a0switch to fat\u00a0burning,\u00a0while\u00a0providing enough fat in the diet\u00a0so the body\u00a0didn\u2019t\u00a0need to break down its own\u00a0fat\u00a0reserves. If this state\u00a0of\u00a0\u201cnutritional ketosis\u201d\u00a0worked, it could be used as a more sustainable alternative to fasting.<\/p>\n In 1921,\u00a0Wilder published\u00a0a paper showing\u00a0that\u00a0it\u00a0did indeed\u00a0work. In three people with epilepsy,\u00a0the ketogenic\u00a0diet reduced\u00a0seizures as\u00a0effectively\u00a0as fasting,\u00a0and could be\u00a0maintained\u00a0for longer.\u00a0Later\u00a0research\u00a0backed him\u00a0up\u00a0and the keto diet\u00a0became an\u00a0epilepsy treatment.\u00a0When new anticonvulsant medications\u00a0came along in the 1930s,\u00a0though,\u00a0Wilder\u2019s diet\u00a0fell out of\u00a0favour,\u00a0only to be\u00a0used\u00a0in\u00a0young children and those\u00a0who\u00a0don\u2019t\u00a0respond to any available medications.<\/p>\n Nevertheless, the fact that it worked suggested that there\u2019s something about \u201cgoing keto\u201d that corrects problems with brain function. Several decades of research later, we have a better idea of what\u2019s happening under the lid when our bodies switch to back-up-fuel mode.<\/p>\n The short answer is: lots of things. The simplest and most obvious is that it involves eating far less sugar. While glucose is our body\u2019s default energy source, having too much of it is known to be disastrous for the health of the body and brain. Long-term overindulging in carbs contributes to inflammation, insulin resistance, diabetes and obesity, while the evidence suggests that high-sugar diets are more likely to lead to low mood in people\u00a0both\u00a0with and without depression.<\/p>\n It\u00a0is possible, then, that some of the\u00a0keto diet\u2019s\u00a0effects come down to bringing us closer to the diet our bodies evolved to expect. \u201cWe are wired to like sugar,\u00a0but in nature,\u00a0sugar\u00a0wasn\u2019t around that much,\u201d\u00a0says\u00a0Guido Frank,\u00a0a psychiatrist at the University of California, San Diego. \u201cIt\u2019s not that sugar\u00a0is\u00a0[always]\u00a0bad for us, it\u2019s about the quantity.\u201d<\/p>\n One upshot of reducing carbs\u00a0is a change in the microbiome.\u00a0Ketogenic diets have been shown to\u00a0inhibit the growth of\u00a0carb-loving,\u00a0pro-inflammatory bacteria in the gut,\u00a0which may\u00a0reduce inflammation\u00a0throughout the body and brain. The\u00a0well-known link between the\u00a0microbiome and mental health, and the role of the gut-brain axis in regulating brain function, may also play a role in improving symptoms.<\/p>\n Some of these effects may be possible without going full keto. The classic ketogenic diet involves reducing carbohydrates from 45 per cent of total calories to just 1 to 5 per cent. Reducing carbs less dramatically, or following a low-glycaemic-index diet that focuses on slow-release carbohydrates instead of simple sugars, might provide at least some of the benefits, says Palmer. \u201cA low-glycaemic-index diet is not necessarily\u202fketogenic, but it\u2019s certainly having anti-inflammatory and insulin-signalling effects and probably affects the gut microbiome as well,\u201d he says.<\/p>\n Other changes, however, do seem to require switching to ketosis. One example is the way ketone bodies appear to act directly on the brain to balance two key neurotransmitters: glutamate, which excites neurons to fire, and GABA, which inhibits their firing. An excess of glutamate, relative to GABA, is associated with the uncontrolled firing seen in epileptic seizures and the erratic brain activity implicated in psychosis. Some of the anticonvulsant medications that are used to treat epilepsy, schizophrenia and bipolar disorder boost GABA relative to glutamate. Evidence from mouse studies suggests that keto diets\u00a0do something similar.<\/p>\n How exactly\u00a0ketone\u00a0bodies\u00a0rebalance\u00a0these\u00a0neurotransmitters\u00a0isn\u2019t\u00a0clear.\u00a0One possibility, however,\u00a0is that\u00a0they simply provide enough energy for the\u00a0brain\u00a0to do\u00a0its\u00a0job properly.\u00a0Ketone bodies\u00a0are\u00a0harder to\u00a0produce in the body\u00a0than glucose,\u00a0but, once formed, are\u00a0a more efficient fuel source for the mitochondria,\u00a0netting 27 per cent more ATP\u00a0per molecule.<\/p>\n A boost of energy in the brain could do more than just\u00a0even out\u00a0neurotransmitter levels. Studies\u00a0focusing on\u00a0schizophrenia,\u00a0bipolar disorder\u00a0and\u00a0depression, as well as Alzheimer\u2019s disease and anorexia nervosa, have found evidence of mitochondrial dysfunction. And while there are many routes to malfunctioning mitochondria \u2013 from genetics to diet and other lifestyle factors \u2013 it does suggest that a problem with releasing energy from glucose may play a role in many brain-related issues.<\/p>\n Carmen Sandi, a neuroscientist at the Swiss Federal Institute of Technology in Lausanne, studies the connection between mitochondrial health and mental illness. She points out that the brain is the most energy-hungry organ, demanding 20 per cent of the body\u2019s fuel at rest, despite only accounting for 2 per cent of body weight. But \u201cthat\u2019s only part of the story\u201d, she says.<\/p>\n Ketone bodies are tiny enough to cross the blood-brain barrier, which means they can be used as fuel for the brain, in place of glucose<\/p>\n JAMES BELL\/SCIENCE PHOTO LIBRARY<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n \u201cMitochondria are not just the energy producers \u2013 they also contribute to the precise functioning of neurons and brain circuits\u201d, with a role in making hormones and other signalling molecules, and in regulating inflammation and managing oxidative stress. There is some evidence that ketone bodies generate less oxidative stress than glucose, says Sandi, so reduce the demand for metabolic clean-up.<\/p>\n For Palmer,\u00a0all of\u00a0this evidence points to a common underlying cause for mental health\u00a0conditions: that\u00a0they\u00a0are\u00a0due to\u00a0metabolic\u00a0problems in the brain. He points to the fact that physical metabolic conditions, such as diabetes, obesity and\u00a0insulin resistance, substantially increase the risk of depression. The reverse is also true: people with mental health\u00a0conditions\u00a0are at greater risk\u00a0of diabetes,\u00a0obesity\u00a0and heart disease.<\/p>\n That ketogenic diets might help treat metabolic problems in the brain first occurred to Palmer in the late 2010s when he was treating a women in her 70s who had experienced debilitating, drug-resistant schizophrenia for more than 50 years.<\/p>\n As is common in severe mental illness, in addition to being extremely mentally unwell, the woman, Mildred, had obesity and her physical health was deteriorating. She was advised to try the keto diet to lose weight. Within weeks, in addition to weight loss, she started to notice improvements in her schizophrenia symptoms. The voices in her head became quieter, her mood improved and, then, after decades of being affected by the condition, she went into full remission. Palmer was amazed, and in\u00a02019 published a paper\u00a0describing\u00a0Mildred\u2019s experience and a similar\u00a0remission result from a second\u00a0person\u00a0with schizophrenia.<\/p>\n It was this research that caught the attention of Robert F. Kennedy Jr., and spawned a grassroots movement spearheaded by the philanthropist\u00a0Jan Ellison Baszucki and her husband David Baszucki, founder and CEO of the tech company Roblox. In 2021, the couple\u2019s son, Matthew, had been struggling with treatment-resistant bipolar disorder for five years. Having run out of other treatment options, he went on the ketogenic diet, under the guidance of Palmer. Within months, he, too, was in remission. The family went on to set up a foundation to fund research in metabolic psychiatry and to share stories from people who have had a positive experience with keto. At the last count, the foundation\u2019s Metabolic Mind YouTube account had more than 97,000 subscribers.<\/p>\n When eating keto, carbohydrates like bread are firmly off the menu<\/p>\n Patrick Chatelain\/www.plainpicture.com<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n Meanwhile,\u00a0research by\u00a0other groups\u00a0added to the excitement, including\u00a0one 2022 study in 31 people, all of whom had previously been hospitalised with severe depression, bipolar disorder or schizoaffective disorder. Of the 31 volunteers who agreed to try the ketogenic diet, 28 managed to stick to it for two weeks or more. All 28 saw some improvement in their symptoms and almost half reached the criteria for clinical remission. However, the study had no control group.<\/p>\n If there is one mental health condition where a fat-burning diet wouldn\u2019t seem to apply, it would be anorexia. Suggesting that people who have a history of disordered eating cut a major food group out of their diet sounds irresponsible and potentially dangerous.<\/p>\n Yet evidence shows that, when people are properly supported and under medical supervision, ketogenic diets might just help. Frank was involved in a 2022 pilot study in five people with anorexia that reported that they were able to maintain a healthy weight on the ketogenic diet with fewer food-related anxieties. Four of the five kept the diet up after the study and continued to improve. \u201cIt was incredible,\u201d says Frank. \u201cI hadn\u2019t seen that before in 20 years of working in this field.\u201d<\/p>\n As with other mental health conditions, there are plausible reasons why going keto might help. For one,\u00a0studies by\u00a0Cynthia Bulik, a clinical psychiatrist at the Karolinska Institute in Sweden,\u00a0and her colleagues\u00a0have shown that anorexia is associated with gene variants linked to inefficient energy release in the mitochondria.<\/p>\n As such, one possibility is that when someone with a genetic metabolic vulnerability starts dieting, the switch to ketosis brings a boost of energy and\u00a0lowers\u00a0anxiety. This, in turn, may reinforce the compulsion to restrict food further, trapping people in a cycle of weight loss that gets out of control. \u201cPeople with anorexia nervosa may have a goal weight,\u00a0but for many of them,\u00a0it\u2019s never enough,\u201d says Frank. \u201cIt\u2019s almost like an addictive process.\u201d<\/p>\n Now, researchers are wondering if a properly balanced ketogenic diet could help people with anorexia to find a delicate balance \u2013 allowing them to get to a healthy weight while removing the compulsion to restrict food. If going into nutritional ketosis can reduce anxiety in a similar way to self-starvation, then \u201cmimicking the underweight state by providing ketone bodies for energy creation might make the need to restrict unnecessary\u201d, says Frank.<\/p>\n It\u00a0is early days, says\u00a0Sahib Khalsa, a psychiatrist who researches and treats anorexia at the University of California, Los Angeles. He adds that keto diets shouldn\u2019t be tried for mental health conditions without a doctor\u2019s support. \u201cThere\u2019s a difference between trying it with an\u202feating disorder psychiatrist who\u2019s monitoring you carefully, and reading about a ketogenic diet and then deciding spontaneously to do it,\u201d he says. \u201cFrom a safety standpoint, I think\u202fit\u2019s definitely premature for that.\u201d<\/p>\n For all the case studies and testimonials,\u00a0keto for the brain is far from\u00a0a done deal.\u00a0Smith points out that there have been no properly controlled,\u00a0randomised\u00a0trials in large numbers of\u00a0individuals, so it\u00a0is impossible to\u00a0know\u00a0what proportion of people will respond as dramatically as Mildred and Matthew\u00a0Baszucki. \u201cThere might be two people who have an excellent response, and that\u2019s great,\u201d he says.\u202f\u201cBut there might be 98 other people who don\u2019t get any response.\u201d<\/p>\n To try\u00a0to\u00a0fill this gap,\u00a0Smith, along with\u00a0Steven Marwaha\u00a0at the\u00a0University of Birmingham, UK,\u00a0is\u00a0beginning\u00a0a\u00a0large-scale,\u00a0randomised\u00a0controlled trial\u00a0in\u00a0200 people with bipolar depression. The study will\u00a0compare\u00a0a nutritional ketogenic diet with\u00a0a diet based on\u00a0UK healthy eating guidelines. The results won\u2019t be in for at least five years, says Smith. In the meantime, the results of a pilot study\u00a0with 27 people that Smith and his colleagues published in 2025 were encouraging, finding a correlation between ketone levels and improved mood and energy levels. Brain imaging also showed a decrease in glutamate levels in brain regions involved in emotional processing.<\/p>\n Another unknown is whether any of the many\u00a0mechanisms\u00a0are more\u00a0important\u00a0than others\u00a0for people\u00a0who might\u00a0benefit\u00a0from the keto diet. \u201cIt is plausible that different individuals derive benefit through different dominant mechanisms, depending on their underlying metabolic and neurobiological vulnerabilities. However, in many cases, the therapeutic\u00a0effects\u00a0likely arise\u00a0from their combined impact,\u201d says\u00a0Shebani Sethi, a metabolic psychiatrist at Stanford University\u00a0in California.<\/p>\n As larger clinical trials get under\u00a0way, and the results continue to roll in, metabolic psychiatry could go\u00a0a number of\u00a0ways.\u00a0Keto diets\u00a0might turn out to\u00a0work very well for some people, and not at all for others, in which case research will focus on\u00a0identifying\u00a0markers that\u00a0indicate\u00a0who\u00a0they\u00a0might\u00a0benefit.\u00a0Or\u00a0further\u00a0research may\u00a0allow us to extract the special sauce from ketogenic diets,\u00a0which could then\u00a0inform new\u00a0drug treatments\u00a0and make\u00a0it unnecessary to\u00a0stick to\u00a0a\u00a0restrictive\u00a0diet.<\/p>\n For now, though, says Palmer, the important thing is to make people aware that, even when they have tried everything, there is still hope. \u201cSome people respond really well to existing treatments, but it\u2019s heartbreaking to see patients year after year, decade after decade,\u202fwho are doing everything we\u2019re asking them to do and they are profoundly suffering. Offering even one additional tool that might work for some patients\u202fis my passion. This is our moment for metabolism and mental health. That\u2019s what I\u2019m hoping.\u201d<\/p>\n Topics:<\/p>\n<\/section><\/div>\n\n","protected":false},"excerpt":{"rendered":" In February,\u00a0Robert F.\u00a0Kennedy Jr., the US secretary of health,\u00a0made a\u00a0characteristically\u00a0bold claim.\u00a0A doctor\u00a0at\u00a0Harvard University,\u00a0he\u00a0proclaimed,\u00a0\u201chas cured schizophrenia using keto diets\u201d. If you happened to be passing Harvard University...<\/p>\n","protected":false},"author":1,"featured_media":3018,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"https:\/\/images.newscientist.com\/wp-content\/uploads\/2026\/04\/21140625\/SEI_294031830.jpg","fifu_image_alt":"","footnotes":""},"categories":[1],"tags":[2643,2642],"class_list":["post-3017","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-rj","tag-depression","tag-diet"],"_links":{"self":[{"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=\/wp\/v2\/posts\/3017","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3017"}],"version-history":[{"count":0,"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=\/wp\/v2\/posts\/3017\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=\/wp\/v2\/media\/3018"}],"wp:attachment":[{"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3017"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3017"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rjbarrett.redirectme.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3017"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Fuelling the brain<\/h2>\n
![\"healthy](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2026\/04\/17131749\/SEI_293510037.jpg\")
<\/div>Ketone bodies<\/h2>\n
![\"Polarised](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2026\/04\/17131736\/SEI_293510553.jpg\")
<\/div>![\"Baguettes](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2026\/04\/17131802\/SEI_293510110.jpg\")
<\/div>Filling the gaps<\/h2>\n