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If you were even tangentially aware of fad diets in the 1990s and have been paying attention to the rise of keto today, you may have had occasion to wonder: What is the difference between the keto diet and the Atkins diet? Both plans emphasize a low-carbohydrate diet that is meant to help you lose weight, but are they the same thing? Sometimes, yes, but also not exactly.

High Protein, Higher Fat

Each is a high-protein diet, so people often focus on the fact that they include a lot of meat, but focusing on that is actually shortsighted, and even a major misconception.

Both the keto diet and the Atkins diet are actually centered on consuming fat. (Yes, really, fat, not simply tons of meat. More on that later.)

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The two diets actually do have a lot in common and overlap in some stages, says dietitian Kristen Mancinelli, M.S., R.D.N., who specializes in low-carb diets.

Related Reading: The Best Low- and No-Sugar Cookbooks for Keto, Paleo, and Diabetic Diets | The Best Keto Costco Buys

Atkins

“The Atkins diet is not different from the ketogenic diet,” Mancinelli says. “The only difference is that Atkins starts you in a ketogenic diet and over time adds carbs back in. So when you are in the ‘induction’ phase of the Atkins diet, which is the beginning, you are absolutely on a ketogenic diet. No difference at all. Atkins says you should stay there for a couple of weeks but recommends you stay longer if you want more aggressive weight loss. It’s really left up to the dieter to decide how long they want to be in be induction [or ketogenic] phase before they move on.”

Keto

So what exactly does a ketogenic diet consist of? The keto diet is a very high-fat diet, with moderate protein intake designed to put the body into a state of ketosis, says Amy Goodson, M.S., R.D., C.S.S.D., L.D., registered dietitian and consultant in the Dallas-Fort Worth area. “This means the body uses ketones as a source of energy instead of glucose or carbohydrate,” Goodson says. (Ketones are a result of the body breaking down fat for energy, which happens when carb intake is very limited; ketones can cross the blood-brain barrier in order to be used as fuel by your central nervous system cells, which otherwise would use glucose—or sugar—from carbs.) The keto diet was actually developed in the 1920s as a natural treatment for epilepsy, and it may also help treat type 2 diabetes by improving your blood sugar levels and reducing a reliance on insulin to regulate blood glucose.

What is the keto diet? (With keto recipes.)

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To successfully put the body into a state of ketosis, you would have to consume 70-80 percent fat, 20-25 percent protein, and 5-10 percent carbohydrates, Goodson says. The Atkins diet relies less on ratios, but the concept is similar: You can eat unlimited protein and fat, and in phase one, you only eat 20 grams of net carbs, ideally from low-carb vegetables, according to Goodson. It may seem counter-intuitive for dieters to intentionally eat more fat, but “The idea is that protein and fat make you feel more full and you will, by default, feel satiated and eat less,” she says.

Another OptionWhat You Should Know About Intuitive EatingAnd sorry to burst your bubble, carnivores, but neither diet is all-you-can-eat meat. “Many people mistakenly believed that the Atkins diet is a high protein diet, but that is just a misconception,” Mancinelli says. “If they read the instructions for following an Atkins diet they would see that it’s not so. You do eat meat, but most of your calories come from fat.”

In addition to protein sources like eggs, fish, poultry and meat, you’ll end up filling up on many healthy fats like olive oil, avocados, tree nuts, and seeds, and low-carb veggies like spinach and kale, if you’re trying to follow either eating plan closely.

Bottom line?

The Atkins diet is a branded ketogenic diet, with a slight twist. “Again, there is no difference and no choosing one over the other,” Mancinelli says. “The Atkins diet provides a plan for increasing carb intake over time, whereas a ketogenic diet is technically ‘all in,’ and once you start reintroducing carbs then you would say you’re no longer on a ketogenic diet…the main difference between the two is that one provides a stepwise process for going off the diet and the other does not.”

There is some concern that both can contribute to heart disease, as they are both high in saturated fat.

Whether you’re looking to meet long-term weight loss goals, alleviate symptoms of illness, or just eat a little healthier, speak with your doctor or go see a registered dietitian to discuss the health benefits of each plan before deciding to try it out.

And if you’re wondering about paleo, it’s also similar in some respects—it’s not a low-fat diet, anyway—but there’s no counting levels of ketones or daily calories or tracking carbs; instead, the focus is on whole foods that our earliest ancestors would have eaten (lean meat, vegetables, fruits, etc.).

Related Reading: What Is the Difference Between Keto and the Paleo Diet?

Keto Concerns

Is the Keto Diet Bad for Your Heart?

Note: This article was originally published on June 11, 2018 and was updated with new text and links on January 3, 2019.

Header image courtesy of Shutterstock.

Kelsey Butler is a reporter and editor based in New Jersey. She has written for a number of health and lifestyle publications, including Women's Health, Brides, and NBC News Better. Hot sauce, black coffee, and bacon make up 50% of her diet.
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