Carbohydrates are a vital part of a balanced diet, with recommendations suggesting that healthy adults should consume between 200 and 300 grams per day. However, some eating plans, like the Atkins and keto diets, propose a different approach, advocating for a significant reduction in carbohydrate intake to promote weight loss and other potential health benefits.
Introduction to Low-Carb Diets: Atkins and Keto
The Atkins and keto diets are two well-known low-carb diets that involve a drastic reduction in high-carb foods, including sweets, sugary drinks, breads, grains, fruits, legumes, and potatoes. Both diets have gained popularity for their potential to aid in weight loss and improve certain health markers. While they share the common goal of carbohydrate restriction, they differ in their approach, structure, and long-term sustainability.
The Atkins Diet: A Phased Approach to Low-Carb Eating
The Atkins diet first appeared in 1972, introduced by cardiologist Dr. Robert Atkins. His book, Dr. Robert Atkins’ Diet Revolution, explained his findings on low-carbohydrate eating, sparking debate and giving his diet a business platform. The Atkins diet has evolved over the years, rebranding its original diet to Atkins 20. The principles of the diet have remained consistent: eat plenty of fat, some protein, and very few carbohydrates to encourage the body to burn fat, not sugar, as its primary energy source.
How the Atkins Diet Works
The Atkins diet doesn't require counting daily calories or limiting fat intake, but it does necessitate careful monitoring of carbohydrate intake. The diet is divided into four phases, using a tracking method called net carbs (total carbs minus fiber) to monitor carb intake.
- Phase 1 (Induction): This phase is the most restrictive, limiting net carb intake to 20-25 grams daily. Acceptable foods include nuts, seeds, proteins, healthy fats, vegetables, and most cheeses. The goal of this severe carb restriction is to promote rapid weight loss. During this phase, the body enters ketosis, burning fat as its main fuel source.
- Phase 2 (Balancing): Carb intake is increased to 25-50 grams of net carbs per day. Weight loss continues, but at a slower pace. Foods allowed include those from phase 1, as well as whole milk, Greek yogurt, ricotta cheese, legumes, and tomato juice.
- Phase 3 (Fine-tuning): The carb restriction is further relaxed, allowing 50-80 grams of net carbs daily. The diet includes foods from the first two phases, along with other fruits, starchy vegetables, and whole grains. This phase continues until the target weight is reached.
- Phase 4 (Maintenance): This final phase is considered the lifetime maintenance phase, allowing 80-100 grams of net carbs per day. All foods from phase 3 can be included, with a gradual increase in carb intake.
Considerations for the Atkins Diet
While restricting carbohydrate intake can support weight loss goals, it's crucial to consider some precautions before starting this diet. Even the fourth phase of the Atkins diet, which allows up to 100 grams of net carbs, doesn't meet the carbohydrate intake recommended by the Dietary Guidelines for Americans. These guidelines suggest that 45 to 65% of daily calories should come from carbohydrate sources, which would be approximately 225 to 325 grams for a 2,000-calorie diet. It’s important to monitor for unwanted side effects of inadequate carbohydrate intake, especially for individuals with type 2 diabetes.
Read also: Understanding the Atkins Diet
The Keto Diet: Achieving and Maintaining Ketosis
Unlike the Atkins diet, which is broken into multiple stages, the ketogenic diet promotes one way of eating for the duration of the diet. Initially developed as part of a treatment plan for children with epilepsy, the keto diet's purported benefits have expanded to include weight loss support. As a high-fat, very low-carb diet, the keto diet aims to help the body reach a metabolic state of ketosis, in which it turns to ketones for fuel.
How the Keto Diet Works
As the body breaks down fat from food sources or stored fat, ketones form. Popular keto resources suggest limiting carb intake to 5 to 10% of total daily calories. For a 2,000-calorie diet, this translates to a maximum of 50 grams of carbohydrates.
Common foods in the keto diet include low-carb veggies, cheese, eggs, poultry, avocado, nuts, seeds, healthy oils, fish, and seafood. The keto diet generally advises against sugary drinks, bread, pasta, rice, and other refined carbs.
Considerations for the Keto Diet
This restrictive diet may present some unwanted side effects. Falling short of daily carbohydrate needs can cause a dangerous drop in blood glucose levels and may lead to nutrient deficiencies. A high-fat diet can contribute to heart disease and other problematic health concerns.
Atkins vs. Keto: Key Differences
Many people consider the Atkins and keto diets to be the same since they’re both low-carb diets that focus on weight loss. However, there are several key differences between them.
Read also: Delicious Atkins Dinners
Carbohydrate Intake Levels
While both keto and Atkins restrict carbohydrate intake, the keto diet is generally more restrictive, also limiting protein intake to ensure that the body uses fat for its primary energy source. The Atkins diet severely restricts carb intake initially but allows moderate protein intake and eventually relaxes the carbohydrate restrictions, allowing up to 100 grams of net carbs per day.
Phases and Structure
The Atkins diet is broken down into four phases, requiring a structured path to weight loss. The keto diet requires one way of eating for the duration of the diet.
Focus on Ketosis
Both the keto and Atkins diets can lead to ketosis. However, only the first two stages of Atkins involve carbohydrate restrictions required to maintain ketosis. As carb intake increases on the Atkins diet, the body will be kicked out of ketosis. The keto diet is based on carb restrictions that promote continuous ketosis.
Long-Term Sustainability
Research is lacking on the long-term viability of restrictive, low-carb diets. Some research even warns against it. Reducing carbohydrate intake so severely can lead to other health concerns.
Atkins and Keto Diet: Similarities
While the Atkins and keto diets present some differences, they also share some similarities:
Read also: Atkins Diet for Vegetarians
Low-Carb Approach
Both the Atkins and keto diets place a lot of pressure on one macronutrient in particular: carbs. Dieters are expected to severely minimize their carbohydrate intake, even going as low as 20 grams of net carbs daily.
Weight Loss Potential
Over recent years, the Atkins and keto diets have primarily focused their marketing on weight loss support. As the body enters ketosis, it tends to burn fat very well. Some studies show that ketosis can help manage obesity and other metabolic risk factors that can lead to type 2 diabetes.
Other Potential Health Benefits
These diets focus on whole foods, reducing the intake of processed foods that can work against wellness. Low-carb diets can help reduce triglyceride levels and increase HDL (good) cholesterol. They may also help regulate blood sugar levels, with a recent study showing that low-carb diets can improve blood glucose and hemoglobin A1c levels more than low-fat diets.
Keto vs. Atkins: Which is Best for Weight Loss?
The Atkins and keto diets have proven their effectiveness for short-lived weight loss. With such severe carbohydrate restrictions, it would be hard not to lose weight quickly. During the first phase of the Atkins diet, with only 20 to 25 grams of net carbs per day, rapid weight loss is likely. The same is true for the keto diet; only 50 grams of carbs per day falls significantly short of the average person’s daily needs, which typically translates to losing weight quickly.
However, when it comes to successful long-term weight loss, sustainable practices are best. Restrictive diets like Atkins and keto can be unrealistic in the long term and may even result in undue mental stress and nutrient deficiencies. If reducing carbohydrate intake can help support wellness goals, consider working with a registered dietitian nutritionist to determine macro needs and design an individualized eating plan.
Potential Health Benefits of Low-Carb Diets
Low-carb diets may offer various health benefits, including:
- Weight Loss: Low-carb diets may result in more weight loss than other diet plans.
- Blood Sugar Regulation: Low-carb diets have been shown to decrease the need for diabetes medications and improve levels of hemoglobin A1c (HgbA1c), a marker of long-term blood sugar regulation.
- Improved Heart Health: Low-carb, higher fat diets may improve certain heart disease risk factors by reducing triglyceride levels and increasing HDL (good) cholesterol.
Downsides and Risks of Low-Carb Diets
Both Atkins and keto have benefits and downsides.
- The ketogenic diet is extremely restrictive and may be difficult to stick to.
- Following a restrictive diet like the keto diet may lead to nutrient deficiencies if you do not pay careful attention to your diet quality.
- Evidence on the long-term safety or effectiveness of the keto diet is limited, so its long-term health risks are unknown.
- Most people can reap several of the benefits of low-carb diets without being in ketosis. Therefore, moderate carb restriction on a low-carb diet like the Atkins diet - as opposed to a strict keto approach - is usually sufficient.
Making an Informed Decision
It’s important to consider weight loss goals, overall health, and dietary preferences when choosing the best eating pattern. Low-carb diets, particularly those focusing on high quality, nutritious foods, can be beneficial. However, higher carb diets that focus on whole foods are just as beneficial for health as low-carb, high-fat diets. Be sure to consult a healthcare professional before making any drastic changes to your diet.