January 5, 2021

What Is the Atkins Diet, and Is It Healthy?

The good and bad of this low-carb diet

variety of protein and fatty foods for adkins diet

A big, juicy hamburger with no bun. Eggs and bacon for breakfast — but hold the fruit. These are examples of meals you can eat on the low-carb, high-fat Atkins diet.


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The Atkins diet has some benefits and can be easier to follow than other diets. But that doesn’t mean you should load up on steaks and butter every night. Registered dietitian Maxine Smith, RD, LD, explains the benefits and risks of this diet plan.

What is the Atkins diet?

Cardiologist Robert Atkins created the Atkins diet in the 1960s. He believed that carbohydrates — not fat — were responsible for health problems and weight gain. As a result, his diet focused on eating plenty of fat, some protein and very few carbs.

“The goal of the Atkins diet is to change your metabolism. You burn stored body fat, rather than carbs, for energy,” says Smith. “And you can do this if you follow the diet closely. But it’s not for everyone, and there may be health risks involved.”

How does it work?

The Atkins diet doesn’t limit the amount of fat you can eat. And you won’t have to count calories or measure portion sizes.

But you will have to count carbs. Carefully. The Atkins diet severely restricts carbs, especially in the early stages. It uses a tracking method called net carbs, which is the total number of carbs minus its fiber content in grams.


“Normally, your body uses carbohydrates as fuel,” explains Smith. “When you don’t eat carbohydrates, your body turns to stored body fat, which the liver breaks down. This process creates ketones, which the body can then use for energy.”

Phases of the Atkins diet

There are four phases of the Atkins diet, starting with the most restrictive and gradually getting easier. “Beginning at phase 1 promotes more weight loss,” Smith explains. “You can start the diet at a later stage, but you won’t lose as much weight.”

  • Phase 1: You eat 20 grams of net carbs a day. For reference, the average banana has 24 net carbs, and a potato has 31. The goal of phase 1 is to produce fast weight loss.
  • Phase 2: This phase allows up to 30 net carbs. You still lose weight, although not as quickly as you did in phase 1.
  • Phase 3: You can increase your net carbs by up to 10 grams per week. Continue this phase until you reach your target weight.
  • Phase 4: This is a maintenance phase, where you can eat up to 120 net carbs a day as long as you stay at your target weight.

Other Atkins plans allow 40 or 100 net carbs from the start. They are designed for people who have less weight to lose or want to maintain their current weight.

Benefits of the Atkins diet

The Atkins diet has been around for decades, and it has some benefits. This diet works for some people because it:

  • Won’t make you hangry: “Protein and fat suppress the appetite, which is an advantage for people who feel hungry on other diets,” Smith says.
  • Cuts calories: If you’re restricting your carbs, you’re also cutting out many unhealthy foods that are common in the American diet. Think white bread, fried foods and sugar. “Most American diets are 55% carbohydrates or higher,” Smith says. “If you cut out all those carbs, you’ll probably eat fewer calories overall and lose weight.”
  • Controls blood sugars: Eating very few carbohydrates can help control blood sugar, especially in people who have diabetes.

Risks of the Atkins diet

Although Atkins can help people lose weight, it has some drawbacks. The diet:

  • Allows processed meats: Who doesn’t love bacon? Well, the American Heart Association, American Cancer Society and World Health Organization, for starters. Processed meats may raise the risk of heart problems and certain cancers. But because they are low carb and high fat, many people following Atkins eat a lot of them.
  • Excludes healthy foods: Many people restrict fruits and some vegetables to stay under their carb limit. These foods contain important vitamins, minerals, disease-fighting phytochemicals and fiber. “Eliminating food groups can cause nutrient deficiencies and health problems,” Smith says.
  • Has side effects: Eating a very low-carb diet like Atkins can cause electrolyte imbalances, constipation, dangerously low blood sugar and kidney problems.
  • Promotes processed foods: The Atkins diet sells and promotes bars, shakes and ready-made meals that help people stick with the plan. But many of these items contain artificial sweeteners, processed ingredients, high-saturated fat and sodium that won’t do your health any favors. “A long list of ingredients isn’t a good sign,” Smith says.
  • Has questionable long-term benefits: “We don’t have evidence that this diet is good for you over the long term,” Smith says. “All of the studies have looked at how it affects your health for less than a year or two.”

Focus on healthy foods

If you decide to follow the Atkins diet, take a whole foods approach:

  • Limit or avoid processed meats and other processed foods.
  • Eat healthy fats, like those found in fish, nuts and olive oil.
  • Include healthy carbs, like fresh fruits and whole grains, as part of a healthy, long-term eating plan.

If you have diabetes or any health conditions, talk to your doctor before starting a weight loss plan. Don’t try Atkins if you’re pregnant, breastfeeding or have kidney disease.

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