Is a ketogenic diet safe? Before you try this at home . . .
First and foremost, if you pick up a copy of Jimmy Moore and Dr. Eric Westman's excellent new book, Keto Clarity (which I highly recommend—see my review here) and feel (understandably) inspired to immediately embark on a ketogenic diet, I would caution anyone with a serious chronic health problem, especially anyone who is taking prescription medications, not to attempt a ketogenic diet on his/her own without medical supervision.
Medications and early ketosis
Even though I personally believe in the power of ketogenic diets to improve and even reverse many chronic illnesses, from diabetes to chronic fatigue to mood disorders, the diet does this by causing very real shifts in body chemistry that can have a major impact on medication dosages and side effects, especially during the first few weeks.
Examples of problematic situations include sudden drops in blood pressure for those on blood pressure medications (such as Lasix, Lisinopril, and Atenolol), and sudden drops in blood sugar for those on diabetes medications (especially insulin). These changes in blood pressure and blood sugar are very positive and healthy, but the presence of medications can artificially intensify these effects and cause extreme and sometimes dangerous reactions unless your dosage is carefully monitored by you and your clinician in the first month or so.
Another important example of a medicine that would require careful monitoring is Lithium, an antidepressant and mood stabilizing medicine. The ketogenic diet causes the body to let go of excess water during the first few days, which can cause Lithium to become more concentrated in the blood, potentially rising to uncomfortable or even toxic levels.
These are just a few important examples, so regardless of what medication you take, please consult with your clinician before getting started. If you are taking lithium or any other psychiatric medication, please read my article: "Ketogenic Diets and Psychiatric Medications."
Special medical and psychiatric conditions
Some health situations which call for careful medical supervision include (please note this is not a complete list):
- People with gallbladder disease or without a gallbladder, because fat is more difficult to digest
- People who have had bariatric surgery (weight loss/gastric bypass) because fats are harder to absorb
- People with rare metabolic disorders that interfere with normal fat metabolism
- Women who are pregnant or breastfeeding, because protein requirements are higher
- Children, because protein requirements vary by age
- People with pancreatic insufficiency, because fats are more difficult to digest
- People prone to kidney stones (perhaps due to salt and fluid balance changes)
- People who are naturally very thin (BMI of 20 or less) because weight loss may occur for some (additional fat calories may be required)
- People with anorexia* (read on below)
*Anorexia and the ketogenic diet
Anorexia bears special mention. As a psychiatrist, I feel compelled to go into some detail about this particular condition. Men and women with anorexia have an irrationally intense fear of weight gain that distorts their perception of body image and is typically associated with an extreme fear of eating fat. Most people with anorexia try to minimize their weight through starvation-level calorie restriction and complete avoidance of dietary fat. This is very dangerous; keep in mind that the body can function perfectly well without carbohydrates but it cannot function without fat. The brain cannot function without dietary fat (approximately 2/3 of the brain is made of fat) and the body cannot digest and absorb vital nutrients without dietary fat as part of every meal.
While it is slowly becoming more common knowledge that carbohydrates are far more fattening than dietary fat, it is rare in my practice to meet a person with anorexia who does not eat carbohydrates regularly (even if it is only secretly during the night and with tremendous guilt . . . ) this is because anorexia causes starvation, and people who are starving get very hungry. When this happens, they tend to choose low-fat or non-fat carbohydrate-rich snacks. They are less afraid of eating sweets and starches than fatty foods, because sweets are lower in calories.
If a person with anorexia decides to embark on a ketogenic diet, it may be tempting to try to do so without eating the proper amount of fat. This can be deadly, because the ketogenic diet already limits protein and severely restricts carbohydrates. If fat is also limited, starvation will rapidly occur, especially if you do not have plenty of body fat to burn for energy.
However, with careful medical and psychiatric supervision, a ketogenic diet rich in healthy fats can be potentially very healing for people with anorexia, as it can restore proper body and brain composition, naturally regulate appetite and weight, and eliminate carbohydrate cravings. Since it is a nutritionally adequate diet high in fat, it is excellent for brain health and can therefore potentially correct the emotional imbalance and cognitive impairment that are typical of this serious illness. There are compelling arguments for the use of ketogenic diets in bipolar mood disorders, as well.
Ready, set, go!
All that having been said, please don’t let these cautionary statements stand in your way—talk to your health care professional about your particular situation, and if he/she does not feel comfortable or knowledgeable enough about the diet, recommend Jimmy Moore's new book, and/or find someone else who is! LowCarbUSA has a list of keto-friendly doctors in the US and Marika Sboros of FoodMed.net has created a Low-Carb Map of the World of low-carb providers.
Even if you do not take medication or have a serious health problem, you may want to consult with a knowledgeable clinician, especially during the first month or two, to help you troubleshoot any issues that may arise, but ultimately the ketogenic diet is a safe and healthy diet for the vast majority of human beings—certainly much safer and healthier than the standard American diet, which should come in a package with a skull and crossbones on it. :) A properly-formulated ketogenic diet contains everything the brain and body require to function well. Not everyone benefits or feels well on it, but most can and do. For those of you who don't feel well on the diet, please read "Freshness Counts: Histamine Intolerance," which explains how "biogenic amines", which are compounds in aged and fermented foods like salami and cheese (very popular in ketogenic circles), can cause miserable food sensitivity symptoms in some people.