What Is the Keto Diet? Here Are the Down and Dirty Basics

By now, if you haven’t heard of the keto diet, we’re going to guess you’ve been living under a rock or you’re actually one of the first people to live on Mars and you’re under some sort of NDA to not discuss it. LeBron James used the diet in 2014 to slim down, former NFL-er Tim Tebow pretty much can’t stop talking it up on morning shows, and — whether you like him or not — Jersey Shore guido Vinny Guadagnino became such an advocate for its weight-loss benefits he’s now “the keto guido.”

But what is the keto diet?

And more importantly, what do you eat when on it, does it work, and how ripped can it help us get? The Manual is here to give you the simple down and dirty on this diet trend.

What Is the Keto Diet?

The keto diet basically asks you to eat almost no carbohydrates, lots of protein, and tons of fats. And we mean a ton of fats, replacing almost all your carb calories with avocados, butter, etc. (To answer Regina George’s age-old question, no, butter is not a carb.) It can be compared to the Mediterranean diet of fish and olives or the Whole 30 trend of zero sugar and zero carbs.

When you’re eating carbs, your cells use blood sugar for energy. Take away those carbs and the cells head for stored fat, breaking it down into molecules called ketone bodies. If your body is using ketones (stored fat) for energy, you are in a state of ketosis, hence the name of the diet. While on the keto diet, it is your goal to be in ketosis.

scale measure weight
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Today, the endless stream of #keto followers (seriously, there are 10 million keto posts on Instagram) prescribe to the diet because it’s notorious for melting fat and boosting energy. (This guy runs 100-mile ultras without carbs.) However, weight loss wasn’t the original objective. Keto began as a dietary cure over 100 years ago for drug-resistant epilepsy, particularly among children. Then in the ’70s, Dr. Atkins — you know, from the Atkins diet — basically initiated the low-carb diet frenzy with a program that began with a two-week ketogenic period.

Getting into Ketosis Takes Days and It Sucks

For the body to enter ketosis and use fat as energy, it takes at least two to four days of eating between 20-50 grams of carbohydrates a day. Sound confusing? If you can’t check in regularly with a nutritionist, you can use a keto calculator or test whether your body is in ketosis using a simple at-home strip.

In those initial two to four days and up to the first few weeks, expect to feel like a bucket of crap. It’s called “keto flu.”

In those initial two to four days and up to the first few weeks, expect to feel like a bucket of crap, since you’ve likely been running off carbs your whole life. This feeling is called “keto flu.”

“Irritability, poor sleep, and dizziness have all been reported issues, as well as a general mental fog,” says Gabby Geerts, registered dietician at Green Chef, a meal kit delivery service. “The brain uses a large portion, roughly 25 percent, of our body’s glucose when resting; in ketosis, the brain has to transition to ketones as its new fuel source. Think of it like a caffeine withdrawal.”

Keto can also mess with your sleep and make you constipated. Then again, the first couple months of going vegan causes, ahem, blockage as well.

What Are the Best Keto Diet Foods?

Technically, Diet A&W root beer and “Carb Smart” Breyers ice cream are keto, just as Oreos are vegan. Bologna, mayo, and pork rinds are also keto. See where I’m going with this?

Just because a food is keto-friendly doesn’t mean it promotes health. Similarly, rock-star foods like apples, black beans, sweet potatoes, and brown rice are big no-nos on the keto diet. So are a lot of vegetables, which primarily contain carbs. Some keto experts even suggest frying the vegetables you do eat in butter.

Here’s Geerts quick list of the best ketogenic foods that are actually healthy:

  • Salmon
  • Avocado
  • Butter
  • Beef
  • Cauliflower
  • Broccoli
  • Asparagus
  • Zucchini
  • Nuts
  • Seeds
  • Healthful oils (such as avocado oil)

The most popular keto-grammed meals will include some variety of bacon, avocado, olives, cheeses, and bun-less double cheeseburgers wrapped in lettuce (which we’re pretty sure is a mortal sin). Keto is an increasingly easy diet to stick to at restaurants, as well; Jimmy Johns makes keto wraps, Chipotle does keto bowls, and every fast food joint from McDonald’s to Chick-fil-A has low-to-no-carb, high-fat options. Here are some of our favorite keto snacks.

Don’t Eat Too Much Protein, Though

In an effort to stay full without eating carbs, keto beginners make the mistake of eating too much protein. Like we said, your goal should be lots of fats, not proteins because too much protein will act like carbohydrates in the body. It’s a process called gluconeogenesis, during which protein is converted into glucose and it will bump you out of ketosis.

Consuming hidden sugars will also hold you back from keto-ing, so watch out for sugar pseudonyms in ingredient labels, i.e. fructose, corn syrup, honey, and lactose.

You Will Fail the Keto Diet Unless You Get Electrolytes

Cutting your consumption of carbohydrates can mess with your vitamin, electrolyte, and fiber levels. Some experts say the No. 1 reason people fail the keto diet is because their bodies become electrolyte-deficient.

Because grains and fruits are restricted on the keto diet, B vitamins, Vitamin C, and iron levels in your body can get wonky. Fiber, which keeps waste moving through the body, can also be in short supply, fudging with the digestive process. That’s where your broccoli, cauliflower, spinach, and plenty of water will come in handy (all keto-approved).

Is Keto Healthy?

A massive study was released in August 2018 that showed a startling correlation between carbohydrate restriction and death, and concluded that “animal-based low carbohydrate diets should be discouraged.” Researchers said that low-carb diets have a way of resulting in lower vegetable, fruit, and grain intake and increased protein intake from animal sources.

Here’s how to successfully go keto, shed weight, and minimize concerns about early mortality: Replace your carbs with more plant-based fat and protein. Instead of lamb, beef, chicken, and pork, favor protein and fat from vegetables and nuts, including nut butter.

Here’s how to successfully go keto, shed weight, and minimize concerns about early mortality: replace your carbs with more plant-based fat and protein.

Other research into the long-term health impacts of the keto diet has suggested it could mess with blood-sugar control and raise the risk for type 2 diabetes (the researchers here tested the diet on mice). Contradictory evidence, though, says short-term use of the keto diet actually improved blood-sugar control for patients with type 2 diabetes. And here we have the perfect distillation of the keto diet argument.

For every study praising its benefits, there’s one suggesting its downfalls. Human studies measuring the long-term, non-weight loss-effects of keto simply aren’t there. But most people who try and love keto attest to the diet’s ability to zap fat, improve energy levels, and bring mental clarity. Which is basically the goal of every diet (and a result of eating healthy).

There’s a reason the keto diet is so stinking popular: It seems to work. Give it a try the healthy way, while still indulging in bacon and burgers without getting out of ketosis. But try not to yo-yo by going heavy-keto for months and then carb-crazy. Yo-yo dieting like this is terrible for your waistline and, more importantly, your physical and mental health.

Article originally published June 2019. Last updated by Sam Slaughter.

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