Low-carb diets are nothing new. Science has shown that eating too many carbohydrates, particularly simple and refined ones, is one of the leading causes of excessive weight gain.(1)(2)
Two of the most popular low-carb diets today are the Atkins and ketogenic (keto) diets. Apart from being low in carbohydrates, these two regimens share many similarities, but they are not the same. Here’s a closer look at the Atkins and ketogenic diets.
Atkins Diet
Dr. Robert C. Atkins believed that the major reason that many people are overweight or obese is because of consuming processed carbohydrates, such as flour and sugar. As a result, he developed the Atkins diet, which is low in carbohydrates but high in protein and healthy fats.(5)
This regimen aids weight loss because the restriction of carbohydrates forces the body to burn stored body fat instead of the glucose produced from carbohydrates. This effectively puts the body into a state of ketosis.
The Atkins diet, however, did not gain widespread acceptance at first because many regarded the idea of consuming high amounts of saturated fats as unhealthy. Eventually, research has proven that saturated fats are harmless, and more than 20 studies over the past 12 years have shown the effectiveness of the Atkins diet.(3)
The Four Phases
Phase 1—Induction
The most important stage of the Atkins diet is the induction phase, which lasts for two weeks. During this period, you need to keep your carbohydrate intake below 20 grams per day. Since the average person consumes 250 grams of carbs a day, the induction period is also the most challenging part of this program.
At this stage, your food intake should come from allowed vegetables, meats, poultry, fish, and shellfish. You should also increase your water consumption.(4) As the induction phase is the most restrictive aspect of the Atkins diet, you are not allowed to eat high carb vegetables (potatoes, sweet potatoes, turnips, carrots, peas, and others), high carb fruits (bananas, oranges, apples, grapes, and pears), as well as legumes (chickpeas, beans, and lentils).
Because of the dietary limitations, most dieters lose a significant amount of weight during the induction phase. You can lose an average of 2.5–5 kilograms (5–10 lbs) or more with the help of exercise.
Phase 2—Balancing
Also known as the Ongoing Weight Loss Phase, the Balancing stage is the stage where you slowly add more carbs back to your diet. The amount of carbohydrates you add should be low enough that you can continue to lose weight.
Every individual’s tolerance to carbs is different so, during this period, your goal is to find the maximum amount of carbohydrates you can consume daily while still losing around 1–3 lbs. per week.
The length of the balancing phase depends on your current weight and your weight loss goals, but, generally, it lasts until you only have between 5 to 10 lbs. left to lose. For some, it takes two months and for others, two years.
Phase 3—Fine-Tuning
The third phase of the Atkins diet is the Fine-Tuning stage, where your intake of carbohydrates is increased by 10 grams per week. During this period, you can eat pasta, bread, and other starchy foods, but the amount should be kept way below the average level. The Fine-Tuning phase lasts until the time your weight loss goes down to 1 lb per week.
Phase 4—Maintenance
As the name indicates, the Maintenance phase is the period when you maintain the healthy lifestyle changes in your weight and eating habits. At this stage, you can start adding more carbohydrates to your diet but go for healthy, complex carbs and avoid simple, processed carbs. You can return to phase 3 if you start gaining weight again.
Pros and Cons
There’s a reason why the Atkins diet is still one of the most popular regimens for weight management, but it doesn’t work for everyone.
Pros
- It puts the body in ketosis, which burns the body’s stored fats instead of carbohydrates for energy. This means you won’t feel hunger pangs unlike in other diet regimens.
- It is flexible because you can add carbohydrates to your diet once you reach a certain tolerance level.
- It can improve your body’s lipid and cholesterol levels, which is helpful not only for weight loss but also for lowering the risk of heart attacks and other diseases related to high cholesterol.(6)
- It is ideal for meat lovers because the list of allowable foods contains many types of meat that are low in fat and high in energy.
Cons
- Carbohydrate depletion can keep you from sleeping soundly during the initial stages of dieting.(7)
- It can lead to stones and other kidney-related diseases in people who have pre-existing conditions affecting their kidneys.(8)
- It can cause constipation, especially in the early phase, because the diet is low in fiber.
- You can be at risk of weight gain relapse if you don’t strictly follow the regimen. This is why following the Atkins diet often requires making several lifestyle changes.
Keto Diet
The keto diet may be one of the most popular diets today, but it has been around since the 1920s when it was originally developed to combat symptoms of epilepsy.(9) The appearance of anti-epileptic drugs in the 1930s, however, made the keto diet unnecessary.
The ketogenic or keto diet is so named because it allows you to enter ketosis, the state where the body burns fat instead of carbohydrates to produce energy.(10) This requires you to lower your intake of carbohydrates and increase the consumption of healthy fats, similar to Atkins. However, in a keto diet you need to consume protein in moderation in order to avoid leaving the state of ketosis because a process known as gluconeogenesis can break down protein into glucose when carbohydrate levels are low.(11)
Types
To achieve a ketogenic state, dieters need to follow a certain ratio when consuming macros. Thus, different types of keto diet have emerged depending on the goals of the dieter.
- The Standard Ketogenic Diet (SKD) is the typical keto diet; it is very low in carbs, moderate in proteins, and high in fat. Generally, SKD contains 75% fat, 20% protein, and 5% carbs.
- The high-protein ketogenic diet is similar to SKD but has more protein, with a ratio that is usually 60% fat, 35% protein, and 5% carbs.
- The Cyclical Ketogenic Diet (CKD) involves periods or days of keto and periods of higher-carb refeeds, the most common of which is following a keto diet during the weekdays and having high-carb meals during the weekends.
- The Targeted Ketogenic Diet (TKD) allows dieters to add carbs around their workouts.
CKD and TKD were primarily developed for athletes, bodybuilders, and other individuals who want to build muscles mass because building muscle requires glucose, which dieters can get from consuming carbs.
Pros and Cons
Like Atkins, the ketogenic diet has its own set of pros and cons that you need to consider before deciding whether this regimen is right for you.
Pros
- It can be beneficial for people who are at risk of diabetes because carb intake is strictly monitored.
- It can help you lose weight without hunger pangs because protein and fat make you feel fuller longer.
- It can help lower the risk of heart disease because the consumption of healthy fats, such as omega-3s, increases the levels of good cholesterol and decreases the levels of bad ones. (12)
- It can control the symptoms of epilepsy as supported by the results of a study conducted by J. Helen Cross in 2008.(13)
Cons
- To maintain ketosis, you need to limit your intake of high carb fruits, which can cause your body to lack essential minerals and vitamins.(14)
- The risk of dehydration is increased since carbohydrates help the body retain water so you need to increase your water intake.(15)
- It may not be ideal for people who have problems metabolizing fat or have other metabolic and digestive disorders.(16)
While there are plenty of reasons to try low-carb diets to lose weight, remember that you shouldn’t cut carbohydrates completely from your diet because you don’t want to be at risk of micronutrient deficiency.
It’s also important to identify the factors that are possibly contributing to your weight gain, such as genetics, stress, diseases, diet, and others to help you better decide whether the Atkins or keto diets are right for you.
Finally, you need to consult with your physician or nutritionist before making any major changes to your diet to avoid adverse effects on your health.