Atkins diet: What’s the secret behind this diet’s 50-year staying power?

You might remember your parents — or even your grandparents — trying the Atkins diet. It’s a low-carb diet that’s been around since cardiologist Dr. Robert Atkins, created it in the 1960s and popularized it in his 1972 book, “Dr. Atkins’ Diet Revolution.”

The diet has remained popular over the years. There are lots of books that walk you through low-carb dieting and provide recipes. And you can buy Atkins shakes, bars, treats and frozen meals to help you meet the diet’s requirements without a lot of meal prep and cooking.

How does the Atkins diet work?

The Atkins diet squarely targets carbs. It limits bread, starchy vegetables and fruit and emphasizes high-protein foods, fat, cheese, lower-carb vegetables, nuts and seeds.

There are various versions of Atkins diets. You can start with a limit of 20, 40 or 100 grams of carbs per day based on your health, food preferences and weight-loss goals.

The Atkins 20 is the original Atkins diet. It’s also a ketogenic diet, at least at first. Sometimes called a ketosis diet plan, this type of eating may help you burn fat.

With Atkins, you move through four phases:

  • Phase 1: Induction. You eat 20 grams of carbs per day or less for at least two weeks to jump-start weight loss. Phase 1 lasts until you are within 15 pounds of your goal weight.

  • Phase 2: Balancing. You eat 25 grams of carbs per day or less and add more carbs slowly until you’re within 10 pounds of your goal weight. You can add some nuts, seeds, strawberries, blueberries, melon, cottage cheese and yogurt.

  • Phase 3: Maintaining. You fine-tune your carb intake until you stay at your goal weight for a month. Many people find they end up at 80 to 100 grams of carbs per day. You see how foods like starchy vegetables impact your progress.

  • Phase 4: Lifetime maintenance. You maintain your weight and adjust your carb intake if your weight creeps up. You can add more fruits and whole grains.

Related: Here’s what dietitians want you to know about cutting carbs and losing weight.

Bonnie Taub-Dix, a registered dietitian and author of “Read It Before You Eat It: Taking You from Label to Table,” told TODAY she thinks the first three phases of the Atkins diet are too restrictive: “If you skip to phase 4, you would still lose weight and be better off than you would be with such severe carb restrictions.”

What does the research say about the Atkins diet?

Some people turn to Atkins because they’re trying to figure out how to lose weight fast. And some studies have given the Atkins diet the edge in short-term weight loss. In a BMJ study, Atkins dieters lost more weight than others in the first month, but weight loss evened out after six months.

And an analysis of five research trials published in the Archives of Internal Medicine gave the edge to low-carb diets over low-fat diets at six months, but results in both groups were comparable after 12 months.

“Weight loss on Atkins is typically seen from eating fewer calories in total, from cutting out carbohydrate foods,” Jen Bruning, a registered dietitian and spokesperson for the Academy of Nutrition & Dietetics, told TODAY.

A review of 107 articles published in the Journal of the American Medical Association found that weight loss was associated with eating fewer calories and dieting for longer, not with eating low-carb foods.

Is Atkins a good choice for you?

There are Atkins diet pros and cons. You might want to try the Atkins diet if you’re looking for quick weight loss and you like the structure of tracking your carbs. Meat eaters have plenty of options on the Atkins diet, but vegetarians and vegans can make it work, too.

With Atkins, eating socially can mean planning ahead. “Avoiding so many types of foods can make eating from restaurants or with your family more challenging,” Bruning said.

On Atkins, you can eat high-fat foods. And while Atkins doesn’t focus on counting calories, it’s a misconception to think you can eat as much as you want. You’re not going to lose weight eating 4,000 calories a day of high-protein, high-fat food.

What do you eat on the Atkins diet?

With Atkins 20, you’ll start out eating foods low in carbs:

  • Certain vegetables, called foundation vegetables

  • Proteins like meat, fish, seafood and eggs

  • Healthy fats

  • Most cheeses

  • Nuts and seeds

Over time you’ll add:

  • Lower-carb fruit

  • Some dairy

  • Legumes

  • Starchy vegetables and higher-carb fruit

  • Whole grains

Related: This diet, first designed to lower blood pressure, packs a ton of good-for-you benefits — including helping you lose weight and keep it off.

Following the Atkins diet, in a typical day you might eat:

There are a lot of packaged Atkins foods you can try, but Taub-Dix says to check the ingredients. “You have to be careful of what you’re looking at in terms of bars and products that say ‘Atkins approved.’ They could be highly processed and not very healthy, with a lot of artificial ingredients and sweeteners,” she said. “Just because it doesn’t have a lot of carbs doesn’t make it a health food.”

The Atkins diet is similar to:

  • Keto diet, which typically limits carbs to 50 grams a day or less

  • Keto/FLEX 12/3, which blends a low-carb diet and fasting

  • Low-carb diets, which restrict carbs to various levels

  • Low-carb, high-fat diet, which pairs a reduction in carbs with an increase in high-fat foods

  • Paleo diet, which tends to be low-carb in practice because it emphasizes a lot of low-carb foods

  • South Beach Diet, a high-protein, low-carb diet with a prepared-food delivery option

Is the Atkins diet effective long-term?

Possibly. While some studies give Atkins the edge for short-term weight loss, it seems to even out with other diets over the long term. Weight loss on Atkins might come from eating fewer calories rather than eating fewer carbs.

Talk with your doctor before starting the Atkins diet or any other diet — your doctor can recommend the best eating plan for you, based on your health needs. “Anyone considering following Atkins should consult a physician first,” said Bruning. “There are multiple conditions and medications that may not be compatible with this style of eating.”