The ketogenic diet —also called the keto diet—has become a popular choice among people who want to lose weight and improve their level of fitness or overall health. To follow the diet, you consume foods that are very high in fat and very low in carbohydrates to get your body into a state of ketosis. Ketosis occurs when your body burns fat, rather than glucose, for fuel.
While the eating program has a history of use in medical settings, there is inconsistent evidence supporting its use for long-term weight loss or overall wellness. If you are considering a keto diet, evaluate how it compares to commercial programs like Atkins and see how it fares against other low carb diets.
The U.S. News and World Report ranks the keto diet number #37 in Best Diets Overall and gives it an overall score of 1.9/5.
There are several areas where the ketogenic diet differs from nutritional guidelines provided by the USDA.
The macronutrient balance of a ketogenic diet varies substantially from the recommendations provided by the USDA.
On a ketogenic diet, it is recommended that you consume about 75% or more of your calories from fat. According to the 2020-2025 Dietary Guidelines for Americans, adult men and women are advised to consume only 20% to 35% of calories from fat, emphasizing healthy fat.
Some versions of the ketogenic diet advise that you choose healthy fats such as plant-based oils, nuts, and seeds. But other versions allow for a high intake of saturated fats from sources such as fatty cuts of beef and full-fat dairy products. USDA guidelines recommend limiting your intake of saturated fat to less than 10% of your total caloric intake.
The USDA guidelines advise that adults consume 45% to 65% of calories from carbohydrates. On a ketogenic diet, you consume just 5% of your calories from carbohydrates.
Your protein intake on a ketogenic diet may align with USDA guidelines. On most versions of the keto diet, you are likely to consume about 20% of your calories from protein. USDA guidelines suggest that you should consume 10% to 35% of calories from protein.
Additionally, the USDA also provides a recommendation for dietary fiber (approximately 22 to 34 grams per day). Those on a ketogenic diet would have a difficult time reaching this goal since fiber is a carbohydrate.
USDA guidelines suggest consuming fruits, vegetables, dairy, grains, and protein. While no food is specifically off-limits on a ketogenic diet, many people who go on the diet may find that some food groups need to be extremely limited or eliminated to reach and maintain ketosis.
For example, those following a ketogenic diet are likely to consume very little fruit and very few grains, as these are primary sources of carbohydrates. In addition, you may not consume many vegetables on the ketogenic diet because many varieties provide too much total carbohydrate.
Calorie counting is not required on a ketogenic diet. There is no specific calorie target on most versions of the program. However, since this diet is high in fat, it is possible that you will consume more calories on a keto eating plan because fat contains more than twice as many calories per gram as carbohydrate and protein.
However, proponents of the keto eating plan suggest that when you follow the program, you end up eating less overall because fatty foods are more satisfying than foods high in carbohydrate.
If your goal is to reach or maintain a healthy weight, you should consume the right number of calories each day—whether you follow a ketogenic eating plan or any other. You can increase your total number of recommended calories by increasing your activity level.
There are very few diets that follow the exact macronutrient breakdown of the ketogenic diet. But some other low-carb eating plans are similar.
- General nutrition: Depending on the specific keto diet you choose, you will consume most of your calories from fat (75% to 90%), limited calories from protein (5% to 20%) and about 5% of calories from carbohydrate. This makes it hard to reach your daily intake of certain nutrients, such as fiber, and vitamins and minerals that you would otherwise get from consuming fruits and vegetables.
- Cost/accessibility: This is not a commercial diet so there is no subscription fee or required foods to purchase. However, many of the keto diets recommend eating foods that are more expensive, such as grass-fed beef and specialty oils like avocado oil or MCT oil.
- Weight loss: While some studies have shown significant weight loss on a ketogenic diet, others have found that this eating style is no better than low-fat or other low-carb diets for long-term weight loss results. In addition, no calorie targets are provided on a keto diet. Therefore, it is possible to consume more calories on this eating plan and gain weight as a result.
- Sustainability: The ketogenic diet is often criticized as being hard to maintain for the long-term. Because the eating program is substantially different from a typical American diet, some consumers have a hard time maintaining the program when eating out or socializing.
The Atkins diet has gone through changes since it was developed in the 1960s. The current version of the eating plan is advertised as being keto-friendly.
- General nutrition: On the Atkins diet, 55% to 70% of calories come from fat. You’ll also consume more protein on the Atkins plan (20% to 30%) and also more carbohydrate (5% to 15% of your total calories) than on a keto diet. Therefore, the Atkins diet provides a more balanced nutritional approach. You are also more likely to get your recommended intake of fiber and important vitamins and minerals, as fruits, vegetables, and whole grains are encouraged during most phases of the eating plan.
- Cost/accessibility: You can follow the Atkins diet by reading any of the Atkins books or by signing up for the program online and getting foods and services delivered for a monthly fee. Following the program based on one of the books is likely to be less expensive. Most of the foods recommended on the plan are easily found in most grocery stores.
- Weight loss: The Atkins program has been studied with mixed results in terms of weight loss. Since the program has changed through the years, results from older studies may not be relevant. However, the current program is more likely to produce weight loss over the long-term as it suggests proper portions for various foods and also includes an activity program to burn calories and improve health.
- Sustainability: The Atkins diet is probably easier to sustain for most people, simply because it provides a more balanced approach to eating. While many consumers may not want to subscribe to the commercial program for an extended period, the Atkins books make it easy to follow the maintenance plan for a longer period of time.
Other Low-Carb Diets
There are many diets that fall into the low-carb category. Some consumers simply cut carbs for weight loss or improved health.
- General nutrition: There is no specific guideline for carbohydrate intake on a low-carb diet, but in general, you might consume 30% of your calories or less on a low-carb eating plan. This provides substantially more carbohydrate than a ketogenic diet. In addition, many low-carb diets are high in protein. As a result, you consume fewer calories from fat. On these eating plans, quality carbohydrates are often emphasized, meaning that you choose whole grains, fruits, and vegetables rather than processed foods that are high in sugar. As a result, you are more likely to meet nutritional goals on a low-carb diet than you are on a keto diet.
- Cost/accessibility: There is no single low-carb diet, but many commercial diets follow a low-carb eating style (such as the South Beach Diet and others). While you might choose to join one of those subscription programs for a fee, there is no cost involved in simply cutting carbs from your meals. Additionally, since low-carb eating has become more popular, many traditionally high-carb foods are now manufactured and sold in low-carb versions. This eating style is more accessible and is likely to be less expensive than a keto diet.
- Weight loss: Many different low-carb eating plans have been studied with mixed results in terms of weight loss. In some studies, low carb diets have been compared to low-fat diets or to low-glycemic diets.8 While there have been various study results, researchers often conclude that the diets most likely to produce weight loss are the diets that consumers can stick to for the long-term.
- Sustainability: A lower-carb diet is likely to be more sustainable than a very low-carb, high fat diet such as the ketogenic diet. A low-carb diet provides a more balanced approach to eating and allows for a wider variety of foods overall.
Similar to Atkins and the ketogenic diet, the Dukan Diet has its roots in the medical community. The eating program was developed by a physician in the 1970s. It is a low-carbohydrate, high-protein approach to weight loss.
- General nutrition: There are four phases of the Dukan Diet: Attack, Cruise, Consolidation, and Stabilization. The first two phases are designed for weight loss and the last two for weight maintenance. On some phases of the Dukan Diet, 79% to 90% of calories come from protein. The diet is very low in fat and allows for moderately low carbohydrate intake. It may be hard to consume enough calories and stay within the recommended macronutrient balance on this plan.
- Cost/accessibility: There are books you can buy to follow this eating plan. There are also some free online resources. However, if you prefer coaching services, you can purchase a plan for a monthly fee. Meals and snacks are also available for purchase, although they are not required to stay on the eating program. Many foods that you find at your local market are allowed on the program, making it cost-effective and accessible for most.
- Weight loss: The Dukan Diet is likely to be effective for weight loss, especially in the short-term. The very low caloric intake will help most consumers lose weight on the plan. However, clinical trials to support the diet’s effectiveness are lacking and diets that are very low in calories are known to backfire. In addition, the diet may be hard to maintain, making it less effective for long-term weight loss or weight maintenance.
- Sustainability: Those who choose to buy coaching services are more likely to stick to this program, although some support groups and other resources (such as recipes) are available online. Others may find it hard to stick to because of the high protein and very low fat intake.