The Atkins diet aims to help a person lose weight by limiting carbohydrates and controlling insulin levels. Dieters can eat as much fat and protein as they want.
Dr. Robert Atkins, an American cardiologist, created this diet in the early 1970s. It has evolved over time and now encourages people to eat more high fiber vegetables and do more exercise than it did in the past.
This article explains how the Atkins diet works, its key principles, its effectiveness, risks, and more.
Dr. Atkins designed a diet to reduce carbohydrate intake significantly. The Atkins Diet has four core principles:
- to lose weight
- to maintain weight loss
- to achieve good health
- to lay a permanent foundation for disease prevention
According to Dr. Atkins, the main reason for weight gain is the consumption of refined carbohydrates, especially sugar, high fructose corn syrup, and flour.
How does it work?
When a person follows the Atkins Diet, their body’s metabolism switches from burning glucose, or sugar, as fuel to burning stored body fat. This switch
When glucose levels are low, insulin levels are also low, and ketosis occurs. In other words, when glucose levels are low, the body switches to using its fat stores, as well as dietary fat, for energy. In theory, this can help a person lose body fat and weight.
When a person eats, their glucose levels rise, and the body produces more insulin to help it use glucose.
The glycemic index (GI) is a scale that ranks carbs from 0 to 100, depending on how quickly they increase blood sugar levels after consumption, and by how much.
Refined carbs, such as white bread and candy, contain high levels of glucose. These foods have high GI scores, as their carbs enter the blood rapidly, causing a glucose spike.
Other types of carbs, such as beans, do not affect blood glucose levels so quickly or severely. They have a low glycemic load and score lower on the GI scale.
Net carbs are the total carbs minus fiber and sugar alcohols. Sugar alcohols have a minimal effect on blood sugar levels. According to Dr. Atkins, the best carbs are those with a low glycemic load.
Fruits and grains are high in carbs, and a person on the Atkins diet restricts these, especially in the early stages. However, these foods are also good sources of vitamins, minerals, fiber, and antioxidants.
To make up for the lack of nutrient-rich foods, the Atkins diet encourages people to use vitamin and mineral supplements.
Using the fat in the body
If there is minimal carbs intake via the diet, ketosis will occur. During ketosis, the body will breakdown fat stores in the cells, resulting in the creation of ketones. These ketones then become available for the body to use as energy.
The Atkins diet is a low carb diet where the body burns more calories than on other diets because ketosis occurs. It is a kind of ketogenic diet, though protein intake is typically higher and fat intake is lower than in a traditional ketogenic diet.
The Atkins diet has four phases:
Phase 1: Induction
A person consumes less than 20 grams (g) of carbs each day. At this stage, carbs come mainly from salad and vegetables, which are low in starch. The dieter eats high fat, high protein food with low carb vegetables, such as leafy greens.
Phase 2: Ongoing weight loss
People gradually introduce nutrient-dense and fiber-rich foods as additional sources of carbs. These foods include nuts, seeds, low carb vegetables, and small amounts of berries. People can also add soft cheeses in this phase.
In phase 2, a person makes the following changes:
- increase daily carbs from 20 to 25 g during the first week
- consume 30 g of carbs during the second week
- increase carbs each subsequent week until weight loss slows to 1 to 2 pounds a week
The aim of phase 2 is to find out how many carbs an individual can eat while continuing to lose weight. This phase continues until the individual is within 5 to 10 pounds of their target weight.
Phase 3: Premaintenance
Dieters increase their carbs intake by 10 g each week. Weight loss will now be slow. They can start introducing legumes, such as lentils and beans, fruit, starchy vegetables, and whole grains to the diet.
People continue in this phase until they reach their target weight and maintain it for a month.
Phase 4: Lifetime maintenance
The dieter starts adding a wider range of carb sources, while carefully monitoring their weight to ensure it does not go up.
Net carb intake will vary between individuals, but it will usually be between 40 and 120 g a day.
Below are the three types of Atkins diet plans.
The Atkins 100 plan
The Atkins 100 diet plan allows up to 100 g of net carbs daily. Within this, the plan involves the following daily allowances:
- three meals of at least 25 g net carbs
- two snacks of 10 to 15 g net carbs
- three servings of protein
- two servings of added fat
This plan involves more grains than other types, and encourages people to choose nutrient rich choices, such as brown rice.
The Atkins 40 plan
This version of the diet starts with 40 g of net carbs per day instead of 20 g.
This plan targets people who want to lose less than 40 pounds. It focuses on consuming vegetables and low-GI fruits, but offers some flexibility to include grains.
The Atkins 20 plan
The Atkins 20 plan is the original and most strict version of the diet, in which people start by restricting net carbs to 20 g daily.
Depending on the phase, people may eat:
- vegetables that are rich in fiber and nutrients, such as broccoli, salad greens, and asparagus
- low sugar, high fiber fruit, for example, apples, citrus and berries
- complex carbs, including legumes, and whole grains
- plant fats such as nuts, avocado, olive oil and seeds
Atkins also offers various premade snacks and shakes that match the diet’s requirements. However, fresh foods are often healthier and more economical than premade diet foods.
Sample menu
A day’s menu might be:
- Breakfast: Cheese omelet with low carb vegetables
- Lunch: Chicken salad with nuts and a side of cherry tomatoes and cucumbers
- Dinner: Meatballs with at least 1 cup of vegetables, such as asparagus, cooked in fat
- Snacks: A hard-boiled egg, Greek yogurt, or nuts.
Foods to avoid or restrict, depending on the phase of the diet, may include:
During induction, some foods, such as carrots, apples, and legumes, are not suitable. In time, however, a person can reintroduce them.
Supporters of the Atkins diet say that exercise is not essential for weight loss. However, they call it a “win-win” activity, as it can help boost energy and overall well-being.
They advise dieters to:
- consume plenty of protein
- get carbs from vegetables
- eat a snack, for example, a hard-boiled egg, around an hour before exercising
- eat a high protein meal within 30 minutes of finishing
Atkins is one of a number of diets that aim to help people manage their weight and prevent related health conditions, such as metabolic syndrome, diabetes, high blood pressure, and cardiovascular disease.
It is important to note that there are few recent studies on the effectiveness of the Atkins diet. More research is available on ketogenic diets in general, but these may differ slightly from the Atkins diet, and therefore may have different effects.
An older
Another older
A 2020 review suggests that keto diets in general may promote short-term weight loss, but that in the long term, their effectiveness is similar to other diets that restrict calories.
More research is necessary to understand the effectiveness and benefits of the Atkins diet.
According to an older
When the body uses fat rather than glucose for energy, ketones can build up before the body uses them efficiently for fuel. This process increases urinary excretion of electrolytes, which may contribute to these symptoms.
The 2006 study authors caution that a low carb diet may not be suitable for everyone, especially those with a risk of kidney disease, as it may make kidney stones more likely.
They add that healthful carbs, such as whole grains, can be beneficial for people with diabetes. Atkins limits the intake of whole grains until the later phases of the diet.
The study also describes the Atkins diet as unpalatable and difficult to follow in the long term.
Authors of a
Long-term dieting concerns
Although maintaining a moderate weight has health advantages, losing excessive amounts of weight quickly through diets such as the Atkins diet does also pose long-term risks.
Some research suggests the Atkins diet may increase the risk of deficiencies in
Research associates these deficiencies with a range of health issues, including fatigue, slow wound healing, cognitive changes, and more.
Losing weight very fast without incorporating exercise may lead to a loss of muscle mass. Some research also links the Atkins diet with an increased risk of all-cause mortality.
To minimize health risks, people can work with a qualified healthcare professional to lose weight.
The Atkins diet may help a person lose weight. For many, losing weight will also reduce the risk of type 2 diabetes, cardiovascular disease, and other aspects of metabolic syndrome.
This diet is a type of ketogenic diet that restricts carbohydrates to help people lose weight.
People who use medication for diabetes, cardiovascular disease, and other conditions should not stop taking these when they follow this or any other diet. Anyone considering a radical change to their diet should talk with a doctor first.