Atkins diet: What you need to know

Atkins diet: What you need to know

The Atkins diet is intended to help a person lose weight by reducing carbohydrate levels and regulating insulin. Dieters are able to eat as much fat and protein as they want.

An American cardiologist, Dr Robert Atkins, developed the diet in the early 1970s. It has grown over time and is now inspiring people to eat higher fiber vegetables and to do more exercise than they have done before.

Get more detail about some of the other common diets here.

What is the Atkins Diet?

A lady eating Atkins diet
High protein, low carb foods are suitable on the Atkins diet.

Dr. Atkins designed a diet intended to dramatically minimize carbohydrate intake. The Atkins Diet has four main tenets:

  • to lose weight
  • to maintain weight loss
  • to achieve good health
  • to lay a permanent foundation for disease prevention

The main reason for the weight gain, according to Dr. Atkins, is the consumption of refined carbohydrates, or carbs, especially sugar, high fructose corn syrup, and flour.

How does it work?

When anyone follows the Atkins diet, the metabolism of their body changes from burning glucose, or sugar, to burning stored body fat as fuel. That switch is ketosis.

When the levels of glucose are low, insulin levels are low and ketosis occurs too. In other words, the body turns to use its fat reserves, as well as dietary fat, for energy when the glucose levels are low. That can, in principle, help a person lose body fat and weight.

Their glucose levels are low before a person eats so their insulin levels are also low. When the person eats, their glucose levels increase, and more insulin is created by the body to help it use glucose.

The Glycemic Index (GI) is a scale that ranks carbohydrates, or carbs, from 0 to 100, based on how quickly and by how much they increase blood sugar levels after consumption.

Refined carbs, such as white bread and sweets, have a high glucose content. These foods have high GI ratings, because their carbs rapidly enter the blood triggering a spike in glucose.

Many forms of carbohydrates, such as beans, don’t so easily or seriously affect blood glucose levels. They have a low glycemic load, and the glycemic index score lower.

Net carbs are complete carbohydrates, minus alcohols in fiber and sugar. The effect of sugar alcohols on blood sugar levels is small. The best carbs are those with a low glycemic load, according to Dr Atkins.

Fruits and grains are high in carbs, and a person on the Atkins diet restricts these, especially in the early stages. Such products, however, are also healthy sources of vitamins, minerals, fiber, and antioxidants.

The Atkins diet allows people to use vitamin and mineral supplements to make up for the lack of nutrient-rich foods.

Using the fat in the body

Ketosis can occur when there is insufficient intake of carbs via the diet. The body breaks down fat stores in the cells during ketosis, which results in the formation of ketones. These ketones then become available as energy for the body to use.

The Atkins diet is a low-carb diet, as ketosis happens, where the body burns more calories than most diets. This is a kind of ketogenic diet but usually higher protein intake and lower fat relative to a traditional ketogenic diet.

Four phases

The Atkins diet has four phases:

Phase 1: Induction

One person consumes less than 20 grams (g) of carbs every day. Carbs come primarily from salad and vegetables at this point which are low in starch. The dieter eats high fat, low carb and high protein products such as leafy greens.

Phase 2: Ongoing weight loss

As additional sources of carbs, people gradually introduce nutrient-dense, and fiber-rich foods. These foods are nuts, seeds, low carb fruits, and small amounts of berries. In this process, people can add soft cheeses too.

In phase 2, a person adds:

  • 20–25 g of carbs per day during the first week
  • 30 g of carbs during the second week
  • 30 g each subsequent week until weight loss slows to 1–2 pounds a week

Phase 2 aims to find out how many carbs an individual may eat while still losing weight. This process continues until the individual’s target weight is within 5–10 pounds.

Phase 3: Premaintenance

Dieters are increasing their consumption of carbs by 10 g each week. Now weight loss is going to be slow. They will begin to add legumes to the diet, such as lentils and beans, fruit, starchy vegetables and whole grains.

People go on in this process until they hit their target weight and maintain it for a month.

Phase 4: Lifetime maintenance

The dieter begins adding a wider variety of sources of carbohydrates, while tracking their weight carefully to ensure that it does not go up.

Net carb consumption can vary from person to person, but is usually between 40–120 g a day.

The Atkins 40 plan

This version of the diet starts with 40 g of net carbs per day instead of 20 g.

Atkins 40®

Each day, people consume:

  • 6–8 servings of vegetables
  • 3–4 servings of protein (4–6 ounces per serving)
  • 3 times 1-tablespoon servings of added fat
  • 3–5 servings of other carbs, with 5 net carbs in each serving

Every week, when the individual is within 5–10 pounds of their target weight, they can add 10 g of net carbs. If they hit their target weight, they will be able to use the Atkins carb counter to help them keep going.

Foods to eat

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

Adequate drinks include water, coffee, and green tea.

Atkins offers numerous premade snacks and shakes that suit the demands of the diet.

However, fresh foods are also safer and more affordable than foods extracted from premade diets.

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

Food to be avoided or limited, depending on the diet process, include:

  • starchy vegetables, such as corn and potatoes
  • fruits with high sugar content, such as pineapple, mango, papaya, and banana
  • sweets, including cookies, candies, cakes, and soft drinks
  • refined or simple carbs, including white bread, pasta, and foods containing processed grains

Other foods, such as carrots, apples, and legumes, are not suitable during induction. Nonetheless, they can be reintroduced by a person over time.

What about exercise?

Atkins diet supporters say exercise isn’t vital to weight loss. They do call it a “win-win” practice, however, as it can help improve 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

Does it work?

Atkins is one of a variety of diets aimed at helping people control their weight and reduce associated health problems, such as metabolic syndrome, diabetes, high blood pressure and cardiovascular disease.

Authors of a 2017 study found evidence that the Atkins diet followed for 12 months could be more effective than other common diets for weight loss.

One study showed that people who followed the Atkins diet scored better on blood pressure, cholesterol levels and weight loss relative to those on the ZONE, Ornish, and LEARN diets.

There is therefore a need for further studies to validate the benefits.


Individuals reported the following adverse effects, especially at the early stages, according to an older 2006 study:

When the body uses fat for energy rather than glucose, ketones can build up before the body makes efficient use of them for fuel. This process increases electrolyte excretion in the urine which can lead to these symptoms.

The authors of the 2006 study warn that a low carb diet may not be appropriate for everyone, particularly those at risk of kidney disease, as it may increase the likelihood of kidney stones.

They add that healthy carbs can be helpful for people with diabetes, such as whole-grains. Atkins restricts whole-grain consumption to the later stages of the diet.

Also, the study describes the Atkins diet as unpalatable and hard to obey in the long run.

A 2019 study’s authors suggest that a low carb diet or ketogenic diet will benefit people with type 2 diabetes and obesity. But they point out that people should see to it that they have a good fiber intake. The authors recommend tailoring every such diet to suit the individual’s needs.


The diet of Atkins can help one lose weight. Losing weight would also reduce the risk of type 2 diabetes, cardiovascular disease and other metabolic syndrome factors for others.

Although a low carb plan does not succeed or be effective for all, clinical trials indicate that the Atkins diet results in equal or greater weight loss in those who follow it for at least 12 months compared with other alternatives, such as Mediterranean or DASH diets.

Individuals who use diabetes medication, cardiovascular disease and other conditions should not stop taking these when following this or any other diet. Anyone contemplating a drastic change to their diet should first speak to a doctor.

Question :

Can I follow the Atkins diet while I am pregnant or breastfeeding?


There is not enough clinical data to examine the long-term effects of the Atkins diet on a pregnant or breastfeeding mother and her child. I typically recommend a more conservative approach to include adequate sources of fiber and nutrient-rich foods to support gut health and growth and development. If the health of the mother warrants a low carb intervention, reducing adding sugars as well as high glycemic carbohydrates rather than a strict Atkins or keto diet is my approach as a dietitian. Natalie Butler, R.D., L.D.

Answers represent our medical experts’ opinions. All material is purely informational and medical advice should not be considered.