06 Feb 2020
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- Though the keto diet requires dieters to consume copious amounts of healthy fats to aid in ketosis, the Atkins diet limits fat and encourages protein consumption instead.
- The Atkins diet has no qualms with processed food, but the keto diet favors whole, fresh foods.
- This article was reviewed by Samantha Cassetty, MS, RD, nutrition and wellness expert with a private practice based in New York City.
- Visit Insider's homepage for more stories.
Both the ketogenic diet and the Atkins diet cut carbs and encourage weight loss, but that's about all they have in common.
The ketogenic diet was created in the 1920s as a therapy for epilepsy, but the diet has gained popularity in recent years as a rapid weight loss tool. Commonly referred to as keto, the diet is similar to other low-carb diets, including Atkins, but its guidelines include some key differences.
According to the Mayo Clinic, a person who consumes 2,000 calories a day should get between 45% and 65%, or 225 to 325 grams, of those calories from carbohydrates. But when you eliminate the number of carbs stored in your body, it goes through a series of adaptations in order to, ultimately, burn fat reserves to get the energy it needs to function. This fat-burning state is called ketosis and the ketogenic diet requires you to remain in this fat-burning state long-term. The Atkins diet, on the other hand, induces ketosis, but only in the first phase.
The makeup of a typical keto diet is around 60% fat, 30% protein, and just 10% carbohydrates, although it's common to go as low as 5% carbs. For someone who consumes 2,000 calories per day, this means eating no more than 50 grams of carbohydrates a day, and sometimes as few as 20 grams. That's about 80 to 200 calories' worth of carbs. This is the way you eat for the entire time you're on the keto diet. The Atkins diet is different.
That Atkins diet is comprised of four phases: induction, ongoing weight loss (OWL), pre-maintenance and lifetime maintenance. The phases start with a dramatic reduction in carbohydrate intake - you're only allowed around 20 grams per day. But then you slowly reintroduce carbs once you achieve your weight loss goals. And once you've maintained your goal weight for a month, you enter the final phase, lifetime maintenance, which as the name suggests, should be the way you eat for life. In this last phase, you can increase your carbohydrate consumption and you're allowed to consume anywhere from 40 to 120 grams of carbs daily.
The Atkins Diet also functions on net carbs. You can calculate net carbs by checking the nutrition labels on your food. Just subtract the grams of fiber you consume from the total grams of carbs and that's your net carb intake for that meal.
Fiber has very little impact on blood sugar, which is why fiber-filled carbs don't count towards your daily limit on Atkins. The keto diet, on the other hand, makes no exception for carbs, fibrous or not.
The keto diet requires generous portions of fat, but the Atkins diet favors protein
According to Amy Miskimon Goss, an assistant professor of nutrition sciences at the University of Alabama at Birmingham, the Atkins diet has traditionally recommended eating protein to subdue hunger, whereas a well-formulated ketogenic diet limits protein and uses fat to soothe a rumbling stomach instead.
Since the Atkins diet is more holistic, especially in its "lifetime maintenance" phase, there are no exact percentages for protein consumption.
The keto diet, on the other hand, is strict in its insistence upon high-fat consumption. In order to maintain ketosis, the keto diet requires dieters to consume a diet of mostly fats. In fact, you should be consuming about 60% to 75% of your daily calories from healthy fats found in foods like avocados, nuts, and extra virgin olive oil.
Keto encourages whole foods, but Atkins does not
Goss explains that a ketogenic diet should also be based on whole foods. This means eating salmon instead of beef jerky, unprocessed foods rather than anything heavily processed with excess sodium, and staying away from artificial preservatives.
The Atkins Diet, however, does not have these restrictions. The Atkins diet company encourages people to eat Atkins-brand bars, shakes and other pre-packaged foods that are specifically designed to support the lifestyle. That said, with the popularity of the keto diet, you can find many keto-friendly, processed, packaged foods as well.
If you're doing a keto diet, you might want to work with a doctor
Goss says that maintaining a keto diet without the assistance of a doctor or nutritionist can be tricky and even dangerous. According to the Merck Manual, a popular resource for medical professionals, eating fewer than 100 grams of carbohydrates every day causes keto acids to accumulate in the body from ketosis. In small amounts, keto acids don't harm the body, but if the body sustains ketosis, the acids can trigger side effects that range from nausea and fatigue to dizziness and abnormal heart rhythms.
"It's critical that patients with any chronic condition, especially diabetes or hypertension taking medication, to consult with their doctor before starting a keto diet because it's likely that medication adjustments will need to be made," says Goss.
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