Whats the Difference Between the Atkins Diet and the Keto Diet?

The Atkins diet and the ketogenic diet (also called keto diet) are two of the most popular diets around. The aim of both programs is simple enough; minimize carbohydrate intake as much as possible to promote weight loss and better overall health.

The current recommended daily intake of carbohydrates for the average adult is between 200 and 300 grams of carbs per day. Under Atkins and keto, these restrictions are much stricter and both diets have similar effects on the body.

Even though the diets are similar in some regards, there are some differences between them. The main differences revolve around when and how carbs are eaten and how they specifically affect the body.

This article will explore the similarities and differences of the Atkins and keto diets, including the potential benefits and risks of the diets and the kinds of foods that can be consumed while following them.

What are the Keto and Atkins Diets?

Both diets aim to improve weight loss and overall health by limiting the amount of carbs a dieter can consume.

Foods that are excluded from both diets include grains, sugars, and most fruits. One difference between the two is that the keto diet promotes eating healthy fat more than the Atkins diet does.

Understanding how different diets work helps to determine which diet would be the right choice for them.

Keto Diet

The people who follow the keto diet eat a lot of fat and some protein and almost no carbs. Here’s a look at how much each macronutrient makes up the diet of the average keto follower;

  • 70-80% fat
  • 20-25% protein
  • 5-10% carbs

Carbs are the main source of energy for the body. By reducing carbohydrate levels in this manner, the keto diet forces the body to use something else for energy instead.

This puts the body in a “ketosis state”, which is when the body begins burning fat to produce ketones. These ketones are the alternative energy source that the body uses when carbs aren’t available. Basically, the keto diet forces the body to burn fat for fuel and so many people follow it to get rid of body fat.

Keto proponents recommend that dieters get their carbs from specific foods such as keto-friendly vegetables (leafy greens), and some fruits (berries in particular). The diet outright excludes legumes and grains.

The Atkins Diet

Much like with the keto diet, the Atkins diet revolves around eating very little carbs, a moderate amount of protein, and a lot of fat. The Atkins diet has evolved over the years to include a range of different eating plans. The name for the most up-to-date version of the Atkins Diet is “Atkins 20”.

The Atkins Diet website says that the diet is broken down into four phases with different carb restrictions based on the phase.

1. Phase One

This phase is the most restrictive one, where dieters are only allowed between 20 and 25 grams of carbohydrates per day. This phase can also last a while, with dieters sticking with phase one until they reach within 15 pounds of their target weight.

2. Phase Two

In Phase 2, the carb restriction is lessened and people eat between 25 and 50 grams of carbs per day.

3. Phase 3

Carb restrictions are further loosened. People can now eat up to 80g of carbs per day until they are able to reach their goal weight and continue to maintain it for a month.

4. Phase 4

This is the maintenance phase where people can eat between 80 and 100 grams of carbs per day.

The fourth and final phase is the least restrictive one. It aims to make people aware of how many carbs they eat and allow them to maintain their new healthy weight.

The body enters the same ketosis state as the keto diet in the first phase. As someone passes through the different phases though, they start to eat different foods and slowly increase their carb intake.

What are the Differences Between the Atkins and Keto Diets?

The diets are both built around a system of reducing carb intake, even for that “less restrictive” fourth phase of the Atkins diet. There are still some differences between the two though;


The keto diet is generally more restrictive than the Atkins one.

The keto diet is built around an emphasis of complete carb elimination. It also puts a heavy restriction on protein as the body can still break down protein for glucose. The vast majority of all calories from the keto diet are from fat.

On the other hand, the Atkins diet places similar carb restrictions at first but it still allows for a moderate protein intake. As the person moves through the stages of the Atkins diet, it becomes less restrictive and allows for dieters to eat more carbs and enjoy a wider variety of food.


Both the Atkins and keto diets can lead to ketosis states. However, only the first state of the Atkins diet (and sometimes the second) involve reducing carb intake enough to maintain this ketosis state. The keto diet, on the other hand, calls for a dieter to maintain their ketosis state throughout the whole process.

Long-Term Viability

There have yet to be any long-term in-depth studies on how beneficial and healthful a long-term low-carb diet can be. If anything, it seems like the reverse could be true.

Research published in the journal The Lancet Public Health in 2018 showed that there was an increased risk of mortality among people who consume a low carb diet rich in animal protein and fat.

The researchers also discovered that consuming a diet with a lot of plant sources of protein and fats could reduce mortality.

Most of those plant sources, such as whole grains, legumes, and nut butters, are also rich in carbohydrates. They would be restricted, if not outright excluded, in a low carb diet.

Some people believe that the Atkins diet can be a long-term option. While it starts out as a restrictive diet, it opens up and allows more freedom when someone gets to their ideal weight.

The final maintenance stage of the Atkins diet is far more manageable than maintaining a heavily restrictive keto diet.

Please keep in mind it can be dangerous to maintain a ketosis state for too long. Please also be aware that some people have trouble maintaining extremely low carb intake or extremely high fat intake for an extended period of time.


The keto diet was originally developed by doctors as a potential treatment for epilepsy in the 1920s. Researches noted at the time that the diet could have other benefits. The diet real entered the mainstream in the 1990s.

The Atkins diet was developed by Dr Richard Atkins. It was created to be a simple and low carb approach to nutrition. The diet has evolved since it was first created and now features four different stages.

The Similarities Between Atkins and Keto

Both diets include a carb restriction and they both have similar effects. Here’s a closer look at the similarities between the two diets;

Weight Loss

The Atkins and keto diets are primarily used to lose weight.

Several studies have shown that diets do indeed lead to weight loss. This is because the body is highly effective at burning fat once it enters the ketosis state. Many relevant studies indicate consuming a low carb diet can lead to more weight loss than a low-fat diet for the short term, but that their results balance out across the long term.

A small-scale study published in Diabetes and Metabolic Syndrome: Clinical Research and Review shows that ketosis could be used to manage obesity and other metabolic risk factors that act as precursors to type 2 diabetes. Further research is needed to fully confirm these findings though.

Potential Health Benefits

A review published in the European Journal of Clinical Nutrition suggests the ketogenic diet could help to protect the body against illness and disease including type 2 diabetes and cardiovascular disease.

These benefits could be thanks to followers consuming less sugar and carb-heavy processed foods.

Emerging evidence also suggests that the diets could help with other issues including acne and certain neurological conditions, although confirming those benefits will take more research.

Focus on Natural Foods

The Atkins and keto diets both encourage followers to avoid processed foods. Highly processed foods have been linked to cardiovascular disease, obesity, and other health conditions.

Side Effects and Risks

There is always going to be some risk of adverse side effects with a diet that involves ketosis. This could include keto skin rashes, keto flu, and keto breath. Remaining in a ketosis state for an extended period of time can also be harmful.

Following either the Atkins or keto diet can also lead to potential nutrient deficiencies because of the restricted dietary requirements. Many people get most of their fiber from carbohydrates. When cutting down carbohydrate intake, make sure to find other sources of fiber such as vegetables.

The two diets could also increase the risk of electrolyte deficiencies and deficiencies in nutrients from fruits and vegetables.

Lastly, ketosis can help to burn fat but it could also lead to the body burning muscle for energy. Sticking to such a low carb diet could lead to muscle loss.


There are several similarities between the two diets. Both the Atkins and keto diet requires a massive reduction in carbohydrate intake and they encourage followers to get most of their calories from fat.

The keto diet has a stricter restriction on where calories come from though. The Atkins diet begins as restrictive, but the restrictions are reduced over time and so people can enjoy a wider variety of foods.

Restrictive diets like these can help with short term weight loss and fitness goals, but they become less effective – and more harmful – over longer periods of time.

Be sure to consult a healthcare provider before beginning a diet or making another significant dietary change. Consulting a professional is particularly important for those with chronic health conditions such as diabetes, high blood pressure, and heart disease.

Whenever following a diet that eliminates food groups, be sure to avoid any nutrient deficiencies by finding other sources of vital nutrients.

Once target weight goals are reached, it could be a good idea to adopt a less restrictive diet that allows for a wide range of nutrient-dense foods. Getting enough physical activity also helps with maintaining a healthy weight.

Last updated: Feb 15, 2020. Bookmark the permalink.

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