Comparing the Atkins and South Beach Diets

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Among low-carb diets, the South Beach and Atkins diets have remained popular for many years. You might wonder about the similarities and differences, and indeed there are both striking similarities and dramatic differences in how Dr. Arthur Agatston and Dr. Robert Atkins designed their weight loss diets.

Similarities Between Atkins and South Beach Diets

The two diets share these similarities:


The structure of the two diets is almost identical. They both start with a restrictive phase lasting about two weeks.

Analysis of the South Beach phase one menus has shown them to have about the same amount of carbohydrates as Atkins Induction (although it could be higher depending upon individual choices).

In the second phase, they both slowly add carbohydrates to find the optimal level for each person. When the desired weight is reached, they go to a maintenance phase.

Emphasis on Finding Optimal Individual Carb Levels

Different people have different sensitivities to carbs, and one thing that's nice about both of these plans is that they are structured to help each person find the number of carbohydrates that works best for them.

“Good vs, Bad” Carbs

Although South Beach advertises this more than Atkins, both Atkins and South Beach differentiate between various carbohydrate sources. They both advise against eating refined carbs (sugars, white flour, etc.).

For other sources of carbohydrates, Atkins has a carb ladder of when to add what foods to the diet, based mostly on glycemic load.

The South Beach diet mostly uses the glycemic index to differentiate between “good” and “bad” carbohydrate sources.

Differences Between Atkins and South Beach Diets

The two diets are different in these ways:


The most obvious difference between the two plans is the advice concerning fat in the diet.

South Beach advises minimizing saturated fat, such as not eating butter or the dark meat of poultry. The oils Agatston recommends (olive and canola) have a lot of monounsaturated fat. He also emphasizes getting adequate omega-3 fatty acids. Agatston doesn’t mention omega-6 fatty acids, and is vague on polyunsaturated fats as a class, but seems to say they are good.

Atkins advises eating a variety of fats. Omega-3s and -6s are recommended to be balanced, which means that many oils that are primarily omega-6, such as corn oil, should be avoided. Saturated fats such as butter are (famously) allowed in greater amounts than they are in South Beach, but omega-3s and monounsaturates are emphasized.

Both hate trans fats (as well they should).

Counting Carb Grams vs. Carb Portions

The way carbohydrates are accounted for is different in the two diets.

Atkins requires counting all carbohydrates that are digestible. Mostly this means carbohydrates that aren’t fiber. Daily carb intake is accounted for by counting every gram eaten. 

South Beach doesn't limit non-starchy vegetables. Other sources of carbohydrates are accounted for by the size and number of portions. Most people would probably find this to be simpler than gram counting.

Is the Atkins or South Beach Diet Better?

Which diet you choose is a personal preference. Since both diets have a two-week introductory period, you may want to try each one and see which works best for you.

The Atkins diet is more structured and requires stricter tracking, while the South Beach diet is flexible and doesn't require carb counting.

The good news is that both have been shown to be effective, so either one may be a good choice for you.

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