For those of us old enough to remember the early 2000s with any clarity (sorry, Gen Z!) the keto diet is reminiscent of another low-carb eating plan: the Atkins diet. Once wildly popular, the diet somewhat faded in the background in favor of other eating plans like Paleo and Whole30. But now that low-carb eating is back on our radar, it seems as though diet trends are just repeating themselves. Given that they’re both low-carb, high-fat diets, they can’t be that different, right? Not quite. Read on for full comparison.
What is keto again?
In case you missed last week’s post, the ketogenic diet is a very low-carb, high-fat, moderate-protein way of eating. Keto macros are very strict with only 5% to 10% of daily calories from carbs, 15% to 20% protein, and a whopping 75% to 80% fat.
The diet was originally created in the 1920’s to help children with drug-resistant epilepsy control their symptoms; it has recently become way more popular among adults due to its ability to burn fat. A healthy keto diet will consist of well-raised animal proteins (grass-fed beef, pasture-raised chicken, and wild-caught seafood), healthy fats (Natalie’s avocados, extra virgin olive oil, nuts and seeds, olives, and coconuts), and non-starchy vegetables, like leafy greens and cruciferous veggies, for fiber and micronutrients.
So what is the Atkins diet?
The Atkins diet has been around since the 1970’s; it was created by cardiologist Dr. Robert Atkins after researching ways people could safely lose excess weight without restricting calories, according to the Atkins website. The eating plan became super popular with celebrities and many of our parents in the early 2000s.
Like keto, Atkins is a low-carb, high-fat diet. It functions in three to four phases, where a person’s macronutrient intake changes throughout each phase. In the first two weeks, you eat less than 20g of carbs per day. Then you slowly add in more carbs from vegetables, nuts, and small amounts of fruit. This means that the macros shift on the diet. So, phase one of the classic Atkins diet (also called Atkins 20) calls for around 10% daily calories coming from carbs, 30% protein, and 60% fat. (This first phase technically puts you in ketosis, according to the Atkins website.) Those ratios shift by the end of the program to allow for more carbs and less fat.
There are other versions of Atkins, like the Atkins 40, which is just a low-carb eating plan that doesn’t have phases in the same way as Atkins 20. It allows for 40g carbs per day and flexible servings of fat and protein.
Keto vs Atkins: What’s the difference?
While both plans are low-carb and high in fat, the macros are a bit different. Keto allows for less protein and more fat than in the strictest phase of Atkins. Another big difference: Keto restricts carbs indefinitely in order to sustain ketosis. Meanwhile, Atkins increases your carb intake during its later phases, thereby taking you out of ketosis. The main focus of Atkins isn’t necessarily to be in ketosis, of course, while that is the main purpose of the keto diet.
It’s important to note that the long-term benefits of a low-carb plan, whether it is Atkins or keto, are up for debate in the health community. Some experts warn that restricting carbs for extended periods of time could cause pretty negative health effects, from constipation due to lack of fiber to disrupting delicate hormone balances in women. Research is also mixed: One 2018 study found that people who cut carbs increased their metabolism and burned more calories compared to people who cut fat, while another one published earlier in the year found no significant difference between low-carb and low-fat plans for weight management. Yet other research has found that low-carb, high-fat diets have the potential to treat diabetes and potentially even schizophrenia. More human clinical trials are needed before we can make definitive conclusions.
However, because Atkins ultimately allows for more carbs than keto, it could come with some health perks that are harder to get on the keto diet. Most people will be able to eat more fruits and veggies in Atkins and therefore getting more fiber, vitamins, minerals, and antioxidants. However, since the keto diet has more guidelines around it, there may be more potential for benefit. Atkins is a little more ambiguous once you get out of the first two phases. With more restriction in keto, you may reap more benefits sooner. But don’t forget, keto is hard to do and carries more of a risk for vitamin deficiency due to the vegetable restriction.
If done properly with limited processed foods, plenty of green vegetables, and well-raised, organic proteins, both diets can be healthy options that lead to benefits. Eat real, whole foods, monitor your carb intake, and move as much as possible. Your body will thank you.
Jacqueline Corbett, ms rd ld
Registered Dietitian, #NKFitSquad Contributor
Women's Health & Fitness Specialist.