Diets that focus on lowering carbohydrates and increasing fat have been associated with lower levels of “bad” cholesterol and higher levels of “good” cholesterol. Furthermore, lower triglyceride levels are typically seen in those on a ketogenic diet. A better cholesterol balance and fewer triglycerides can help to protect against plaque deposition in the arteries, which can lower your risk of atherosclerosis, heart disease, heart attacks, and stroke.

These types of back-and-forth weight fluctuations can contribute to disordered eating, Kizer says, or can worsen an already unhealthy relationship with food. “I think this diet appeals to people who have issues with portion control and with binge eating,” she says. "And in many cases, what they really need is a lifestyle coach or a professional counselor to help them get to the bottom of those issues."
"The diet was introduced in the 1920s as a way to treat epilepsy and then sort of fell out of popularity with the introduction of anti-seizure drugs," Turoff says. What's more, ketosis (the goal of keto, a state where the body uses fat for energy instead of carbs) is something seen in people during periods of starvation—including in people with anorexia nervosa. "The body is deprived of carbohydrates and thus has to turn to ketone bodies as a fuel source," Turoff explains. "People really need to understand that it's not just a low-carbohydrate, high-fat diet—it actually changes the way your body uses fuel."

What about heart health and the keto diet? Previous older schools of nutrition would purport that a diet rich in fats (specifically saturated fats) would be detrimental for heart health, but more recent research suggests that saturated fat is not as bad as previously believed.  There is actually a tiny little bit of evidence that a keto diet may improve triglyceride, HDL and LDL levels. Like here and here. An even more recent study found that a keto diet improved triglyceride, HDL and LDL levels. We’ll definitely have to wait to see how that research unfolds because there is definitely a lot of competing elements at play.
This diet also entails weight loss because it gets rid of excess water content in the body due to a lower amount of insulin produced. The food is broken down into simple sugars, with excess energy stored as complex sugars. The pancreas produces insulin that helps regulates sugar breakdown in the body. The body needs less sugar in switching to higher intake of fat. The liver can break down fatty acids to energy in ketogenic diets. Due to eating less carbohydrate or sugars, the production lowered. In a study, 90% of all type 2 diabetics were able to lower or completely eliminate their diabetic medication after 6 months of being on a low carbohydrate diet.
If you’re science oriented, you can also try his 2008 book “Good Calories, Bad Calories”. For a more journalistic view on the events that led to fat phobia starting in the 1950’s (as well as the joke that is the Mediterranean Diet), there is also Nina Teicholz’s 2014 book “The Big Fat Surprise.” Be sure to check out youtube for some of these folks’ lectures and discussions. They are not advocating whacky stuff.
Other potential culprits, Dr. Ede notes, are grains and legumes, which not only interfere with absorption of brain-healthy nutrients but are also high in lectins and other factors that may pose risks to brain health. Cutting out refined carbohydrates, refined oils, grains and legumes through the low-carb high-fat (LCHF) or ketogenic diet may improve mental health, just as doing so can reverse diabetes and promote weight loss, she notes. 
To be clear, most of the hype you’ll hear about how the ketogenic diet can ward off cancer is taking things too far. While there is a fair amount of research regarding cancer, studies have been limited to animals. One review published in Redox Biology highlighted some of them, indicating promising results for colon, gastric, and prostate cancers. Maybe more interesting are the few case studies involving human subjects. Bear in mind, we’re talking about a handful of people. In these cases, implementing a ketogenic diet seemed to halt disease progression.
All of our cells need fuel to function. This fuel comes from three sources: fat, carbohydrates and protein, called macronutrients. Too much protein without fat puts us at risk for a handful of complications, so protein can never healthily serve as a primary source of fuel. We are left then with fat and carbohydrates as the main providers of energy – the energy that allow us to do everything from breathing and blinking as we veg out on the couch to swimming the English Channel. Our cells’ preferred fuel comes from carbohydrates, which are easily converted to glucose, which, in turn, is readily converted to energy. This is why athletes “carb load” before they compete. Peak performance occurs when the body has plenty of glucose and glycogen stores available at hand. When glycogen runs out, that’s when the body turns to fat. When there is no more blood sugar for our cells to consume, they seek an alternative form of energy. This energy comes from ketones, which are compounds our body produces from stored fat. So a ketogenic diet is one that is high in fat and very low in carbohydrates, resulting in the production of ketones to be used for fuel instead of glucose.
What is the ketogenic diet exactly? The classic ketogenic diet is a very low-carb diet plan that was originally designed in the 1920s for patients with epilepsy by researchers working at Johns Hopkins Medical Center. Researchers found that fasting — avoiding consumption of all foods for a brief period of time (such as with intermittent fasting), including those that provide carbohydrates — helped reduce the amount of seizures patients suffered, in addition to having other positive effects on body fat, blood sugar, cholesterol and hunger levels. (1)
One of the mechanisms of a ketogenic diet in epilepsy may be related to increased availability of beta-hydroxybutyrate, a ketone body readily transported through the blood-brain barrier. In support of this hypothesis, it was found that a ketogenic diet was the treatment of choice for glucose transporter protein syndrome and pyruvate dehydrogenase deficiency, which are both associated with cerebral energy failure and seizures (26).
Prior to the advent of exogenous insulin for the treatment of diabetes mellitus in the 1920's, the mainstay of therapy was dietary modification. Diet recommendations in that era were aimed at controlling glycemia (actually, glycosuria) and were dramatically different from current low-fat, high-carbohydrate dietary recommendations for patients with diabetes [1,2]. For example, the Dr. Elliot Joslin Diabetic Diet in 1923 consisted of "meats, poultry, game, fish, clear soups, gelatin, eggs, butter, olive oil, coffee, tea" and contained approximately 5% of energy from carbohydrates, 20% from protein, and 75% from fat [3]. A similar diet was advocated by Dr. Frederick Allen of the same era [4].
Although many proponents recommend this high fat version of Keto for weight loss, it first gained notoriety as a treatment method for Epilepsy. Going as far back as the 1920’s, medical professionals have recommended high fat Keto Diets as a treatment method for difficult to control seizure disorders. However, a diet that includes a high percentage of fats as part of its eating program increases the daily caloric intake. More calories means slower fat loss. Therefore, the higher calorie count is why this Ketogenic Diet type is considered a slower weight loss model for dieters and is why the Ideal Protein Protocol is a more effective Keto Diet for weight loss.
"Your brain runs on glucose (a simple form of carbohydrates)," notes Adrien Paczosa, R.D., L.D., a registered dietitian and eating disorder specialist. "When you cut out carbs, your body has to 'make' carbs from breaking down other parts of the body. This results in what I like to call a hungry brain. You experience slower cognition, memory loss, headaches, and confusion." That doesn't sound so great, right? "Also, those who suffer from depression and anxiety may have higher levels of those periods when not eating carbs on a regular basis." Because of this, keto might not be the best choice for those with mental health issues.
The one important caveat: Eating keto also ups the risk for diabetic ketoacidosis, a life-threatening condition where fat gets broken down too fast and causes the blood to become acidic. It’s much more common in people with type 1 diabetes, but if you have type two and are eating keto, talk with your doctor about what you should be doing to diminish your risk.
I must note here, that as a nutrition professional who has worked in pediatrics and seen children who must follow this diet, it is incredibly challenging for both the child and family. Most people who must follow this diet for therapeutic medical reasons have trouble actually reaching ketosis with diet alone, and need to drink poor-tasting formula drinks to keep their carb-to-fat ratio in tight control. Many of these individuals must follow this way of eating to survive or have any sort of quality of life.
Additionally, you may find it difficult to eat adequate calories on a daily basis because fat is so filling. Some people even opt to fast for several hours each day. While this may help with weight loss, your body needs those calories for proper maintenance. Without them, it may turn to burning muscle for energy, and that can accelerate muscle loss.
Longer-term studies conducted on animals have shown the KD may be associated with some adverse events. For example, in rodent studies, some will develop nonalcoholic fatty liver disease (defined as liver damage that is not due to excess consumption of alcohol, viral or autoimmune causes, and iron overload ) and insulin resistance when put on the keto diet long-term. Other studies suggest that some individuals may be predisposed to heart-related problems if they eat a very high-fat diet for an extended period of time.

Low-calorie, low-carbohydrate diets are increasingly recognized to be more satiating than low-calorie mixed diets (meaning, overall calorie intake is reduced to promote weight loss).7 Many people on the keto diet commonly experience the feeling of being more satisfied after eating, and this could contribute to weight loss–but scientists have yet to find a clear advantage of keto for weight loss when compared to any other calorie-controlled diet.
You might be surprised to learn that many non-keto friendly foods are associated with a whole lot of health benefits – so by cutting them out, you forgo many of their perks. Fruit, for example, is brimming with a range of antioxidants that help to fight damage to your body’s cells. Another example is grain foods, which are associated with reduced risk of heart disease, diabetes and some cancers. Same goes for legumes, too.
The research on how diet affects PCOS is minimal, but there is one compelling study on the ketogenic diet and women with PCOS. In this study, five overweight women ate a ketogenic diet (20 grams of carbohydrates or less per day) for 24 weeks. The results were astounding — average weight loss was 12%, free testosterone decreased by 22%, and fasting insulin levels dropped by 54%. What’s even more impressive is that two of the women became pregnant despite previous infertility problems.
×