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Should You Try a Keto Diet?

How healthy is a high-fat ketogenic diet?

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Q: What are “keto” diets? I can’t open a magazine or a website without reading about them.

Ketones (also known as ketone bodies) are metabolic by-products of fat burning. “Keto” diets (short for ketogenic) induce your body to make more of them.

A ketogenic diet by definition is a very low-carb diet. By keeping carbs really low – as low as 20 grams a day – you can force your body to produce more ketones than it normally would. The idea is that if you reduce your body’s supply of carbohydrates, the body will be forced to burn fat to create more ketones and then use those newly created ketones as a source of fuel.

So ketogenic diets are the true “fat burning” diets. This is one reason they’ve been used by so many weight-loss docs, most famously by Robert Atkins, MD, whose Atkins Diet was a keto diet before the term “keto” ever became popular.

Remember, carbs are quickly broken down into glucose and used by the body as immediate fuel. But carbs are like kindling, while fats are the logs that keep your metabolic fire burning. Your goal is always to be a more efficient fat burner.

Many people who are either obese or very resistant to weight loss have become, in popular parlance, “sugar burners,” meaning their bodies have learned to run on sugar, the dietary equivalent of kindling. These folks have huge fat stores – just ask them, they’ll point to them – but they can’t access that fat and use it for energy. Because ketogenic diets force the body to use fat, they have been very useful for weight loss, especially when nothing else works.

Everyone generates ketone bodies – especially when you go without food for a long time, like during sleep. But with a very low-carb diet, you generate ketone bodies above the “normal” level (measurable by a blood or urine test), at which point you’re said to be “in ketosis.” For Atkins, ketosis (also known as nutritional ketosis) was the holy grail of fat loss.

Ketone bodies, as it turns out, are an absolutely wonderful source of fuel. The heart loves ketone bodies (aka ketones), as does the muscular system. And so does – we’ll come back to this in a minute – the brain.

But keto diets have a lot of applications besides weight loss. Ketogenic diets are an accepted treatment for childhood epilepsy and are used in top hospitals across the country, including Johns Hopkins.In fact, hospitals that do not offer ketogenic diet programs for childhood epilepsy are penalized in hospital rating systems.

And although there’s not a ton of research on this yet, ketogenic diets appear to be promising as an additional treatment for cancer, according to research published in Redox Biology, European Journal of Clinical Nutrition and Nutrition & Metabolism. Since researchers theorize that glucose is the main source of fuel for tumors, they found that a low-carb, high-fat diet could be a helpful strategy for patients after conventional cancer treatments such as chemotherapy. Additionally, the noted integrative neurologist David Perlmutter, MD, has publicly stated that he tries to stay in ketosis as much as possible as ketones are terrific brain fuel.

And then there’s the brain, which I promised we’d come back to.

One of the reasons ketogenic diets work for epilepsy is that they help stabilize brain waves. And that feature of the diet has gotten the attention of the US Navy.

In conjunction with the University of South Florida, Tampa, the Navy is seriously researching ketogenic diets for use with the Sea, Air and Land (SEAL) teams. Apparently, some of these super-elite troops have to dodge helicopter fire underwater and sometimes have to descend deep really fast. The Navy is hoping that keto diets may help these guys avoid some of the horrible consequences of quick submersion and ascent, such as the bends. So far, it’s looking promising.

So why is everyone not on a keto diet? For one thing, they’re difficult to stay on. It’s hard to keep carbs to 20 to 50 (or even 70) grams a day. And keto diets are not without their own challenges – like, where do you get your fiber if you’re eating 75 to 80% of your calories from fat? And what does not having enough fiber do to your microbiome?

At this point, it’s safe to say that ketogenic diets – if done correctly and under the guidance of someone who knows what they’re doing – are a safe and effective tool for certain conditions. They’re not necessarily for everyone, but they are a boon for many, especially in therapeutic applications. Like any dietary regimen, keto has its challenges, but it also has some impressive rewards.