What “keto” means?
The “keto” in a ketogenic diet comes from the fact that it allows the body to produce small fuel molecules called “ketones”. This is an alternative fuel source for the body, used when blood sugar (glucose) is in short supply.Ketones are produced if you eat very few carbs (that are quickly broken down into blood sugar) and only moderate amounts of protein (excess protein can also be converted to blood sugar).
The liver produces ketones from fat. These ketones then serve as a fuel source throughout the body, especially for the brain.
The brain is a hungry organ that consumes lots of energy every day, and it can’t run on fat directly. It can only run on glucose… or ketones. On a ketogenic diet, your entire body switches its fuel supply to run mostly on fat, burning fat 24-7. When insulin levels become very low, fat burning can increase dramatically. It becomes easier to access your fat stores to burn them off. This is great if you’re trying to lose weight, but there are also other less obvious benefits, such as less hunger and a steady supply of energy. This may help keep you alert and focused.
When the body produces ketones, it enters a metabolic state called ketosis. The fastest way to get there is by fasting – not eating anything – but nobody can fast forever. A keto diet, on the other hand, can be eaten indefinitely and also results in ketosis. It has many of the benefits of fasting – including weight loss – without having to fast.
A Detailed Guide to the Potential Health Benefits and Risks of the Keto Diet
To say that the keto diet has become one of the most popular diets of recent years is a complete understatement. Case in point: There are more than one million searches on Google every month for the keto diet. It’s unique because the fad diet has captured the interest of people who want to lose weight — and there’s no shortage of reported success stories to be found.
But researchers have taken a greater interest in it as a medical diet, too. In 2015, there were 159 studies listed in the database PubMed (which is run by the U.S. National Library of Medicine and the National Institutes of Health). In 2018, that number doubled, with 322 published studies.
The Keto Diet, Defined: A Brief Primer
So what is the keto diet?
The diet calls for consuming high amounts of fat, a moderate amount of protein, and a very limited amount of carbs. It’s usually broken down to 75, 20, and 5 percent of your daily calories, respectively, says Pamela Nisevich Bede, RD, a dietitian with Abbott’s EAS Sports Nutrition in Columbus, Ohio. Compare that with the typical American diet — which is usually 50 to 65 percent carbs — and it’s safe to say this is a completely different way of eating, Nisevich Bede says.
The diet calls for consuming high amounts of fat, a moderate amount of protein, and a very limited amount of carbs. It’s usually broken down to 75, 20, and 5 percent of your daily calories, respectively, says Pamela Nisevich Bede, RD, a dietitian with Abbott’s EAS Sports Nutrition in Columbus, Ohio. Compare that with the typical American diet — which is usually 50 to 65 percent carbs — and it’s safe to say this is a completely different way of eating, Nisevich Bede says.
After you follow the diet for a few days, your body enters ketosis, which means it has started to use fat for energy. Newbies on the diet find it helpful to track whether they’re in ketosis with a urine ketone strip or a blood-prick meter, but Nisevich Bede says you’ll eventually learn what ketosis feels like and will know whether you’re in it.
Is a ketogenic diet safe for you?
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.
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)
