Can a Ketogenic Diet Reduce ADHD Symptoms?
The low-carb, high-fat keto diet is popular for a reason: it is a powerful tool for achieving and maintaining weight loss, plus it’s shown to help patients with seizures, diabetes, and high blood pressure. So could it be used to treat ADHD symptoms naturally as well? Here is what the science tells us to date.
The Amazon Best Seller list is stacked with cookbooks dedicated to the ketogenic diet, which is equally inescapable in health magazines, talk shows, and transformation photos across Instagram. This popularity is due, in part, to studies linking a keto diet to impressive weight loss, insulin stabilization, and decreased seizures in children. Which naturally leads patients searching for non-pharmaceutical ways to reduce ADHD symptoms to ask: Can it work for ADD, too?
The short answer: Maybe. No solid research about the ketogenic diet and ADHD yet exists, however early indications suggest that it may reduce some symptoms.
The Keto Diet — How It Works
Like the Atkins, Paleo, and South Beach diets, a ketogenic diet is very low in carbohydrates. But unlike those diets, the keto diet is high in fats. There is no set of standard intake ratios for a keto diet, but popular versions comprise 70–80 percent fats (e.g. cheese, cream, meat, eggs), 10–20 percent protein (fish, meats, seeds, nuts are all OK), and about 5–10 percent carbohydrates (this means cutting out sweets, rice, grains, white potatoes, milk, beans and most fruit), according to a diet review by the Harvard T.H. Chan School of Public Health.
With carbohydrate intake drastically reduced, a person’s body runs out of glucose stores to use for energy and so it uses dietary and stored fat instead, turning it into molecules called ketone bodies. This metabolic process is called ketosis, and is sometimes described as tricking the body into thinking it’s starving.
The keto diet is currently most popular for its weight-loss benefits (a 2013 study from Brazilian researchers found it more effective than a conventional low-fat diet), but studies indicate it may be used to control type 2 diabetes and improve symptoms in people with mild-to-moderate Alzheimer’s disease.
The diet has been around for decades. In the 1920s, doctors discovered that a strict ketogenic diet could reduce, and even eliminate, seizures in children with some forms of epilepsy. Though there is no medical consensus explaining why a ketogenic diet reduces seizures, one recent study led by UCLA scientist Elaine Hsiao, Ph.D., suggests that the keto diet changes key gut bacteria that affect neurotransmitters in the brain.
A Keto Diet for ADHD?
ADHD, like epilepsy, is a brain-based disorder. So could a keto diet likewise reduce ADHD symptoms? Heidi Pfeifer, R.D., LDN, a clinical dietitian specialist at Massachusetts General Hospital for Children, has seen positive evidence.
Pfeifer has spent more than 20 years treating epilepsy in children for whom medications do not work. When these children are put on a strict or liberalized version of the keto diet (40–60 grams of carbohydrates per day), ADHD symptoms improve. “We have seen improved behavior and focus with both versions independent of full seizure control,” says Pfeiffer.
A 2001 Johns Hopkins study points to the same result. Looking at 65 children with epilepsy who were put on a ketogenic diet for one year, researchers saw “significant behavioral improvements in attention and social functioning” in the children, and a reduction in epileptic seizures.
But following a strict keto diet is not easy. In a 2010 New York Times article, writer Fred Vogelstein detailed the extreme caution that he and his wife used when carefully measuring and weighing every bit of food for their epileptic son, Sam; even a slight variation from the diet would lead to a cascade of seizures, he reported.
“For kids with ADHD, the classic ketogenic diet is really hard,” says Pfeifer. She recommends making an appointment with a registered dietitian who understands low-carb diets. To gradually transition to a low-carb, high-fat diet, “take out sugar, processed food, and foods made with white flour, dye, or additives,” Pfeiffer says. “Leave in fruits, vegetables, and whole grains — foods with high nutrient value.” This kind of eating throughout the day prevents peaks and valleys in blood glucose levels that cause the cycle of feeling energetic, then crashing with fatigue. She adds that many people who eat this way report better energy and better moods.
Downsides of the Keto Diet
Some people who go on the keto diet initially experience headaches, fatigue, irritability, nausea and difficulty sleeping — a cluster of reactions sometimes referred to as “keto flu,” according to Marcelo Campos, M.D., in a recent Harvard Medical School health blog. This is not flu at all, and the negative symptoms are usually temporary; if not, Dr. Campos advises seeing a doctor.
When staying on the diet long term, developing kidney stones is another risk, especially if adequate hydration is not maintained, Pfeifer says. Like any other treatment, following a new and restrictive diet should be done with the guidance of a doctor or knowledgeable registered dietitian. Limiting carbohydrates may limit intake of essential micronutrients, so it is important to supplement with the appropriate vitamins and minerals to avoid deficiencies. And it should be noted that most keto studies are short term; the long-term impact of a keto diet is not fully understood.
And some experts are wary. “Ketogenic diets do have evidence of helping with seizures and may reduce hyperactivity in individuals with epilepsy,” says Joel Nigg, Ph.D., author of Getting Ahead of ADHD: What Next-Generation Science Says about Treatments That Work—and How You Can Make Them Work for Your Child. “Beyond that, the ketogenic diet, per se, is not sufficiently studied in ADHD to support recommending it for that purpose in non-epileptic individuals.”
Abby Langer, a Toronto-based registered dietitian, and mother to a daughter with severe ADHD and anxiety, is worried that parents may unnecessarily put their child onto a keto diet: “There is zero evidence that the diet will help with ADHD — for children or adults — and it’s extremely concerning to me when people put their children on diets,” she says. “It’s a highly restrictive diet that can impact a child’s growth and health if not done correctly. It can also establish unhealthy eating behaviors in children that may then end up as disordered eating.”
Langer is also against labeling foods as good or bad. “It’s never a good thing to tell a child that otherwise healthy foods are ‘bad or ‘off limits’ unless there is a serious, legitimate reason for avoiding those foods,” Langer says. “I don’t think ADHD qualifies as this.”
Each adult and child with ADHD is unique; for some people, more conservative steps may be effective in treating symptoms. “If individuals with ADHD want to consider dietary intervention, they can supplement with omega-3 fatty acids (fish oil or algae supplements), reduce food additives by eating less preprocessed and packaged food, or consult a dietician to undertake a hypoallergenic or restriction diet,” Nigg says. “Each of those (dietary interventions) has some modest empirical support for a subset of individuals with ADHD.”
But, he warns, “Any restriction diet should be done under dietetic or medical supervision to ensure adequate nutrition, particularly in developing children, and may also require supportive counseling since these diets are difficult to undertake.”
Curious? Keto Recipes Worth Trying
What do everyday meals look like on a keto diet? Bacon and scrambled eggs made with spinach is one popular keto breakfast. Lunch may include a tuna salad with quinoa, or a cheeseburger without the bun. Roast chicken, salmon, or steak with a side of asparagus makes for a keto dinner.
Want to know more about keto diet meals? Try any one of these kid-friendly recipes from Cristina Curp who has written several cookbooks featuring healthy keto recipes, including the new Made Whole: More Than 145 Anti-Inflammatory Keto-Paleo Recipes to Nourish You From the Inside Out. Curp says she does not follow the traditional keto macronutrient ratio. “I just stick to low-carb, high-fat real food,” she says. “My family eats the same way I do, but with the addition of some fruit and safe starches.”
Keto Recipes to Try: