You may spot low-carb and sugar-free ice cream in your grocery store’s freezer case. Take one look at the ingredients, though, and you’ll find artificial colors, potentially moldy corn products, and sucralose that can harm your gut bacteria. This version tastes like a dirty keto recipe, but sweetens the results with grass-fed butter, collagen protein, and simple flavors like cocoa powder and cinnamon.
The popular low-carb diets (such as Atkins or Paleo) modify a true keto diet. But they come with the same risks if you overdo it on fats and proteins and lay off the carbs. So why do people follow the diets? "They're everywhere, and people hear anecdotally that they work," McManus says. Theories about short-term low-carb diet success include lower appetite because fat burns slower than carbs. "But again, we don't know about the long term," she says. "And eating a restrictive diet, no matter what the plan, is difficult to sustain. Once you resume a normal diet, the weight will likely return."
Ketoacidosis, on the other hand, is dangerous. But it’s usually limited to people with type 1 diabetes, striking when their glucose levels rise due to illness or a missed insulin dose. Without insulin, cells can’t take in glucose, so they burn fat for fuel instead, producing exceptionally high ketone levels—much higher than the amount generated by the keto diet. That, in combination with high blood glucose levels, essentially poisons the blood. “It’s very easy to tell the difference between nutritional ketosis, which has no negative symptoms [aside from ‘keto breath,’ which can smell like nail polish remover], and dietary ketoacidosis, which is an illness that requires hospitalization and causes lethargy, abdominal pain, nausea, vomiting, rapid breathing, and lack of appetite,” says William Yancy, MD, program director at the Duke Diet and Fitness Center in Durham, North Carolina.
Ketosis is an adaptive state that allowed our ancestors to survive temporary food shortages. When food was not available at all, or the only food available was extremely low in energy (such as leaves and grasses), their bodies could start to break down their body fat reserves after a couple of days. Ketone bodies were generated as a result allowing them to sustain their brains and preserve their muscle and other vital proteins.
“I really believe that the more informed you are about the benefits of a healthy bite versus the chain reaction that you’re going to put into effect in your body when you take that bite — you just suddenly don’t want to make that choice for yourself anymore. It’s beyond willpower at that point; it’s become a desire to do something good for yourself.” — Christie Brinkley
During the 1920s and 1930s, when the only anticonvulsant drugs were the sedative bromides (discovered 1857) and phenobarbital (1912), the ketogenic diet was widely used and studied. This changed in 1938 when H. Houston Merritt, Jr. and Tracy Putnam discovered phenytoin (Dilantin), and the focus of research shifted to discovering new drugs. With the introduction of sodium valproate in the 1970s, drugs were available to neurologists that were effective across a broad range of epileptic syndromes and seizure types. The use of the ketogenic diet, by this time restricted to difficult cases such as Lennox–Gastaut syndrome, declined further.[10]

The ketone bodies are possibly anticonvulsant; in animal models, acetoacetate and acetone protect against seizures. The ketogenic diet results in adaptive changes to brain energy metabolism that increase the energy reserves; ketone bodies are a more efficient fuel than glucose, and the number of mitochondria is increased. This may help the neurons to remain stable in the face of increased energy demand during a seizure, and may confer a neuroprotective effect.[56]


No animal on earth lives permanently in ketosis. Omnivorous animals such as bears and dogs, and obligate carnivores such as cats – the ultimate low-carbers – use gluconeogenesis to transform amino acids from protein into glucose[1]. This allows them to maintain optimal blood glucose levels to fulfill their bodies’ needs for this vital nutrient. Only in prolonged starvation or a diabetic state will these animals enter ketosis.
Potatoes and gravy are total comfort food — and luckily, there’s a keto version. These are made with cauliflower, which is quite low-carb, particularly when compared to potatoes. Made with cream, butter, rosemary and parmesan, this mash is creamy, full of flavor and smooth. You’ll finish it all off with a stock-based gravy, that would be perfect on a roast, too.
There are three essential components of all food: fats, carbohydrates and protein. The ketogenic diet is a carefully prescribed ratio of fats to carbohydrates and protein. This ratio causes the body to convert fat into substances called ketone bodies (thus the name). These ketones are then used for fuel in many cells of the body, including the brain. When this happens, the brain goes into a higher energy state and is better able to protect itself against seizures.
There are many ways in which epilepsy occurs. Examples of pathological physiology include: unusual excitatory connections within the neuronal network of the brain; abnormal neuron structure leading to altered current flow; decreased inhibitory neurotransmitter synthesis; ineffective receptors for inhibitory neurotransmitters; insufficient breakdown of excitatory neurotransmitters leading to excess; immature synapse development; and impaired function of ionic channels.[7]
Bulk buy and cook. If you’re someone who doesn’t like to spend a lot of time in the kitchen, this is the best of both worlds. Buying your food at bulk (specifically from wholesalers) can reduce the cost per pound tremendously. Plus, you can make ahead food (bulk cook chicken thighs for pre-made meat, or cook entire meals) that are used as leftovers, so you spend less time cooking.
On the ketogenic diet, carbohydrates are restricted and so cannot provide for all the metabolic needs of the body. Instead, fatty acids are used as the major source of fuel. These are used through fatty-acid oxidation in the cell's mitochondria (the energy-producing parts of the cell). Humans can convert some amino acids into glucose by a process called gluconeogenesis, but cannot do this by using fatty acids.[57] Since amino acids are needed to make proteins, which are essential for growth and repair of body tissues, these cannot be used only to produce glucose. This could pose a problem for the brain, since it is normally fuelled solely by glucose, and most fatty acids do not cross the blood–brain barrier. However, the liver can use long-chain fatty acids to synthesise the three ketone bodies β-hydroxybutyrate, acetoacetate and acetone. These ketone bodies enter the brain and partially substitute for blood glucose as a source of energy.[56]
As in adults, glucose is the predominant cerebral fuel for the fetus and newborn. Studies in experimental animals and humans indicate that cerebral glucose utilization initially is low and increases with maturation with increasing regional heterogeneity. The increases in cerebral glucose utilization with advancing age occur as a consequence of increasing functional activity and cerebral energy demands… glucose plays a critical role in the developing brain, not only as the primary substrate for energy production but also to allow for normal biosynthetic processes to proceed.
Missing Nutrients. One of the biggest concerns for dietitians is the keto diet’s lack of key foods. Many question the eating plan’s impact on the development of certain chronic diseases. Without milk, for example, getting enough calcium and vitamin D for sturdy bones becomes a challenge. Take away whole grains, fruit, beans, and potatoes, and it’s nearly impossible to consume enough potassium for healthy blood pressure or enough fiber to stay regular. And unless you’re eating lots of low-carb, leafy green vegetables, you miss out on vitamins A, C, K, and folate, too. 
Although many hypotheses have been put forward to explain how the ketogenic diet works, it remains a mystery. Disproven hypotheses include systemic acidosis (high levels of acid in the blood), electrolyte changes and hypoglycaemia (low blood glucose).[19] Although many biochemical changes are known to occur in the brain of a patient on the ketogenic diet, it is not known which of these has an anticonvulsant effect. The lack of understanding in this area is similar to the situation with many anticonvulsant drugs.[56]

First reported in 2003, the idea of using a form of the Atkins diet to treat epilepsy came about after parents and patients discovered that the induction phase of the Atkins diet controlled seizures. The ketogenic diet team at Johns Hopkins Hospital modified the Atkins diet by removing the aim of achieving weight loss, extending the induction phase indefinitely, and specifically encouraging fat consumption. Compared with the ketogenic diet, the modified Atkins diet (MAD) places no limit on calories or protein, and the lower overall ketogenic ratio (about 1:1) does not need to be consistently maintained by all meals of the day. The MAD does not begin with a fast or with a stay in hospital and requires less dietitian support than the ketogenic diet. Carbohydrates are initially limited to 10 g per day in children or 20 g per day in adults, and are increased to 20–30 g per day after a month or so, depending on the effect on seizure control or tolerance of the restrictions. Like the ketogenic diet, the MAD requires vitamin and mineral supplements and children are carefully and periodically monitored at outpatient clinics.[48]
On your keto food list, stick to low-glycemic sweeteners to avoid spikes in blood sugar, and avoid fillers and binders such as maltodextrin and dextrose, which can spike blood sugar and contain sneaky carbs. Sugar alcohols such as maltitol or xylitol may read as no sugar on a label, but be aware that they will still cause moderate glycemic response when digested.
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Even hibernating bears do not go into ketosis[2]. And predatory animals who undergo extended periods of food deprivation, such as elephant seals[3], are metabolically resistant to ketosis; instead, they have upregulated gluconeogenesis pathways through which they can steadily produce glucose. This makes perfect sense, since predators’ survival depends on their ability to catch their prey, which usually requires intense bursts of activity. And sprinting capacity is dependent on glucose, as humans who adopt a ketogenic diet quickly discover.
I have great respect for Harvard Medical School. I notice that they support their readers posting comments and I am most appreciative of the article and all the many thoughtful comments by the readers. The readers seem to have the most expertise here and I hope that the doctor who wrote the article will think long and hard about the comments by readers. After 35 years of clinical practice in mental health, I notice that all issues of emotion involve medical issues, nutrition, and the gut bacteria. I would say that these issues and all of the executive brain functions seem to improve with ketogenic principles. For those that apply it in a flexible and smart manner, it appears to improve every area of their lives. I strongly encourage the author of the article to take one class via The Institute for Functional Medicine. If he is open to more learning he can take more classes and get certified. I’m sure a fine doctor, he will be an even better doctor and personally healthier, if he gets more training. Are we all open to new learning(especially us healthcare providers)?
Most people have probably heard of the Atkins diet, which is a pretty general take on ketogenic eating. Wildly popular in the 70s and again in the 90s, Atkins and the low-carb diet are one of the best ways to lose weight. In fact, one of the biggest benefits to low carb eating is that it is a very efficient way to lose weight without much effort. The combination of filling meals that reduce overeating and the fact that, when you’re in ketosis your body burns stored fat for energy makes this an ideal diet for people whose primary goal is fat loss.
My point here is that the warnings about the ketogenic principles are well taken and well documented. My concern is implications that this is a fad. I don’t use the word diet with my patients and I’m concerned that the principles behind the label and the real results that these readers have commented on might get minimized. I have found it best to encourage patients to read authors like: Stephen Phinney, Jeff Volek, Patricia Daly, and Charles Gant and the be partners with their doctors and check blood work as they move along. I am not for or against the article. If ketogenic principles offer people enduring, satisfying, and cohesive change then why not read about its potential and flexilbity?
It seems like everyone is talking about the keto diet — the high-fat, low-carb eating plan that promises to turn your body into a fat-burning machine. For that reason, keto has surged in popularity over the past year as a lose-weight-fast strategy. Thank Hollywood A-listers and professional athletes like Halle Berry, Adriana Lima, and Tim Tebow who’ve publicly touted the diet’s benefits, from shedding weight to slowing down aging. Here’s everything you need to know about going keto.
Because some cancer cells are inefficient in processing ketone bodies for energy, the ketogenic diet has also been suggested as a treatment for cancer.[59][60] A 2018 review looked at the evidence from preclinical and clinical studies of ketogenic diets in cancer therapy. The clinical studies in humans are typically very small, with some providing weak evidence for anti-tumour effect, particularly for glioblastoma, but in other cancers and studies, no anti-tumour effect was seen. Taken together, results from preclinical studies, albeit sometimes contradictory, tend to support an anti-tumor effect rather than a pro-tumor effect of the KD for most solid cancers.[61]
Low carb diets focus on keto recipes (also known as ketogenic recipes) like the ones below to keep your blood sugar stable, helping your body regain insulin sensitivity and keeping your mood and energy levels stable. Also, since processed food has so many additives – usually sugar included – low carb diets encourage you to cook for yourself. This leads to eating more whole foods and improving your diet in that way as well.
There are three essential components of all food: fats, carbohydrates and protein. The ketogenic diet is a carefully prescribed ratio of fats to carbohydrates and protein. This ratio causes the body to convert fat into substances called ketone bodies (thus the name). These ketones are then used for fuel in many cells of the body, including the brain. When this happens, the brain goes into a higher energy state and is better able to protect itself against seizures.

If you’re looking to get a jump start on your health and fitness goals this year, you may be thinking about trying the ketogenic diet. Maybe you’ve heard the phrase before — it’s a huge diet buzzword — but aren’t sure what it means. Here’s a primer: The ketogenic diet is an eating plan that drives your body into ketosis, a state where the body uses fat as a primary fuel source (instead of carbohydrates), says Stacey Mattinson, RDN, who is based in Austin, Texas.
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