First, the good news: most people can adopt a ketogenic diet! No need to overthink this. If you enjoy salmon and asparagus, or beef and broccoli, then you’re most of the way there. More good news: you’ll begin to experience the many benefits of keto in just a few weeks, and if you prepare for the transition, you can head off many of the transient side effects, collectively referred to as “keto flu.”
Here’s the catch: To reach ketosis, you’ll be eliminating a lot of the foods that are probably staples in your current diet. Out goes sugar in any of its forms, both obvious (in cookies) and sneaky (in canned tomato sauce). You’ll also give up those inflammatory grains – in fact, I encourage everyone, keto or not, to rid their diets of wheat, corn, and oats. Eliminate starchy vegetables. This means potatoes, of course, but also sweet potatoes and cooked carrots. Keto diets do not include legumes or much in the way of fruits. Dairy fats (butter, ghee, heavy cream) can be part of the plan, but some dairy products, such as milk, are out; others, such as hard cheeses, can be enjoyed in small amounts. And of course you’ll be eating plenty of good, healthy fats. That’s the basic plan. So read on if you’re willing to make these changes.
Before you commit to a ketogenic diet, let’s look at some of the most common exclusions and limitations. It’s a small but important list: in fact, it consists mainly of genetic disorders that would interfere with your body’s ability to utilize fats as fuel. Because these disorders cause major problems very early in life, it’s unlikely that you have reached adulthood without a diagnosis. If you know that you have one of these genetic disorders, you should definitely NOT begin this diet:
- a primary (i.e., inborn, not acquired) carnitine deficiency
- a fatty acid oxidation pathway defect
- pyruvate carboxylase deficiency
- porphyria (usually inherited, but possibly acquired)
The following list of “relative contraindications” is much broader, and if one or more of these apply to you and you decide to proceed with the diet anyway, you may require specialized medical and nutritional oversight. In other words, you may still be able to implement the diet, but it’s essential that you have a supportive and readily available keto-savvy team before you begin.
- You are currently either pregnant or lactating.
- You are considering implementing this diet for a child.
- You are unable or unwilling to restrict alcohol intake until after you are keto adapted.
- You have one or more of the following issues:
- either primary or metastatic liver cancer
- elevated liver enzymes (high enough to suggest liver damage)
- structural or functional change to your gastrointestinal tract (e.g., esophageal surgery; bariatric surgery)
- type 1 diabetes
- type 2 diabetes that is poorly controlled or for which you take a medication that puts you at high risk for ketoacidosis (e.g., an SGLT2 inhibitor, such as canagliflozin [Invokana])
- intractable constipation as a side effect of painkillers (opiates)
- difficulty swallowing
- slowed gastrointestinal motility due to neurological impairment or neurodegenerative disease
- gallbladder obstruction
- history of pancreatitis
- certain heart conditions (including an elongated QT interval or a rhythm disorder)
- certain renal diseases
- short bowel syndrome
- sarcopenia, or cachexia due to cancer (which needs intense management)
- red flags in your bloodwork (high or low values) that suggest underlying metabolic issues or impaired immune function
Other health issues, such as kidney stones or gout, usually don’t preclude embarking on a ketogenic diet, though you should work closely with a practitioner who can monitor both symptoms and treatment (if any is needed). In some cases medications may need to be monitored or adjusted. Examples include drugs used to treat high blood pressure (including diuretics), diabetes drugs (including those noted above), steroids used to control inflammation (such as prednisone or dexamethasone), and opiates used for pain relief (such as hydrocodone or fentanyl). Hormones used to treat thyroid disease may cause a rise in morning glucose levels, and some people prefer to switch to overnight dosing. Talk to your healthcare practitioner before you make any changes to medications.
I hope this brief summary has cleared up some of the headline-grabbing misinformation that abounds online. See you on the path!
Adapted from Miriam Kalamian’s book Keto for Cancer: Ketogenic Metabolic Therapy as a Targeted Nutritional Strategy (Chelsea Green Publishing, 2017) and reprinted with permission from the publisher.
