South Beach Diet vs. Nutrisystem

December 16 2019

Both of these approaches can help you lose weight.

This article is based on reporting that features expert sources.

There are many different diets and approaches to weight loss that you can try when it’s time to shed a few pounds. Some have been around longer than others, and some require a little more effort on the part of the dieter. Two common diets that many people turn to when they want some help losing weight include the South Beach diet and Nutrisystem.

South Beach Diet Overview

In 2003, cardiologist Arthur Agatston published a best-selling book titled, “The South Beach Diet: The Delicious, Doctor-Designed, Foolproof Plan for Fast and Healthy Weight Loss.” This book established the principles of his now widely used South Beach diet, that aims to help people lose weight and improve heart health. Additional books with recipes and tips followed, and eventually an entire diet company was born, with options for a meal delivery service for people seeking to follow the plan.

The basic premise of the South Beach diet uses a phased process and a good-bad approach to certain carbohydrates and fats to help dieters shed weight quickly. Dieters start with a 14-day restriction phase, called phase 1, in which bread, pasta, potatoes, rice, baked goods, sweets, ice cream, alcohol, sugar and even fruit are strictly off limits. The idea is to halt sugar dependence and shake up the metabolism to shift the body into a fat-burning mode.

The diet promises to help you drop 8 to 13 pounds in that first two weeks if you follow it to the letter. It also boasts of improved internal health, with a focus on better cardiovascular health.

“You will have corrected the way your body reacts to the very foods that made you overweight,” Agatston explains in his book. “There’s a switch inside you that had been turned on. Now, simply by modifying your diet, you’ll have turned it off. The physical cravings that ruled your eating habits will be gone, and they’ll stay away as long as you stick with the program.”

After that initial two weeks, you’ll begin adding back some carbohydrates, but only the good ones such as brown rice and some fruits. This phase 2 is designed to be less restrictive, and you’ll stay in this phase until you reach your goal weight. You can expect to lose about 1 to 2 pounds per week in phase 2, which conforms to recommendations from the Centers for Disease Control and Prevention about safe and sustainable weight loss.

The third and final phase of the diet is a “more liberal” maintenance phase intended for dieters who have achieved their desired weight loss, Agatston writes. This phase is intended to be followed long term and looks a bit like a Mediterranean diet with lots of vegetables and fresh fish, lean meats and some dairy.

Across all phases of the diet, the South Beach approach favors inclusion of low-glycemic carbohydrates over high-glycemic carbs. Low-GI carbs do not trigger as intense an insulin response in the body, meaning that they can help you maintain a steady blood sugar level. A steady blood sugar level eliminates spikes and crashes in blood sugar, which can affect energy levels throughout the day or trigger overeating in some people.

The diet also emphasizes healthy fats. Instead of unhealthy saturated and trans fats, such as can be found in baked goods, processed meats and French fries, the diet includes healthier monounsaturated fats such as olive oil and avocado. These foods have been linked with positive implications for heart health.

Nutrisystem Overview

Founded in 1972 as a brick-and-mortar operation in Fort Washington, Pennsylvania, Nutrisystem has grown to become one of the leading providers of prepared meals and nutritional support for people seeking to lose weight. The company offers counseling and a range of resources for members via the phone and internet.

“Nutrisystem is a program that looks at balanced nutrition,” says Courtney McCormick, a registered dietitian and manager of clinical research and nutrition with Nutrisystem. Portion control and management of blood sugars are the name of the game.

Nutrisystem relies on an understanding of the glycemic index – values assigned to foods based on how they impact blood sugar levels – to drive its program. A lower-carb, higher protein ratio can help support weight loss, and that principle guides the company’s approach to nutrition. Nutrisystem also seeks to keep carbohydrate intake consistent throughout the day, which can help eliminate spikes and crashes in blood sugar that can lead some people to overeat.

Clients purchase pre-made food items directly from the company, but are also encouraged to supplement these ready-to-eat meals with fresh foods and their own meals. “We provide about 60% of the person’s calories for the day, and then we provide guidance for them to add in fresh grocery additions,” McCormick says. Clients can select from a variety of shelf-stable and frozen prepared options.

Web-based resources, including a new app and lifestyle blog, are also intended to support today’s dieter. But the company still emphasizes personal counseling and support. “Everyone who’s on our program has access to nutritional counselors,” McCormick explains. “They can call in anytime they have questions or need motivation.”

For dieters with diabetes, these resources include certified diabetes counselors. “They can help those individuals personalize their meal plans,” she says.

Health Benefits

Both the South Beach diet and Nutrisystem can help you achieve weight loss, and thus they can induce health benefits. The health benefits of losing weight if you’re overweight or obese are well documented and include reduced blood pressure, reduced risk of developing type 2 diabetes, reduced risk of stroke and reduced risk of some cancers.

South Beach. Registered dietitian and certified sports nutritionist Shawn Wells, based in Dallas/Fort Worth, says one of the benefits of the South Beach diet is that it can make you more aware of what you’re eating and how those foods might impact your health. “It encourages fresh, whole foods, which is optimal.” The phased approach is good because it “allows for progress as you are on the diet.” He says the idea that you need to “earn” your carbs is another helpful way of thinking about food as fuel that can encourage more physical activity. “When you’re exercising, you allow yourself more carbohydrates as you can utilize this fuel.”

Nutrisystem. With Nutrisystem, because you don’t have to count calories or weigh food, that takes a lot of the guesswork out of sticking with the plan and staying on target to lose weight. Having access to nutritional counselors and coaches is also a helpful way to stay motivated and work towards your goal in a healthy way.

Health Risks

South Beach. Wells says that while the South Beach diet can trigger weight loss, “it may be too low in fat for improving heart health. The Mediterranean, Atkins and keto diets are higher in healthy fats and have been shown to improve heart health,” but the South Beach diet is lower in fat. “Low-fat diets actually lower HDL,” which is the good type of cholesterol that can actually protect your cardiovascular health. Because low-fat diets can make these levels drop, that could “possibly put you at higher risk for heart disease,” he explains. Therefore, he cautions against becoming “fat-phobic” as a means of cutting calories when using the South Beach diet.

Also, because the diet can be restrictive, especially in the first phase, it can be triggering for individuals who currently have an eating disorder or those who have battled eating disorders in the past. Wells also notes that the South Beach diet is likely unnecessary for some people, specifically those who are very active. “Lean, insulin-sensitive athletes may not need to follow the South Beach diet at all, or those working highly intensive jobs,” because they get so much exercise. This diet is more helpful for “the sedentary, insulin-resistant individual.”

Nutrisystem. The Nutrisystem program is balanced, so if you’re eating a variety of foods, it should cover all your nutritional bases. In response to user feedback that the diet could be a little too rigid, especially when dieters are faced with social events or other food-centric experiences where they can't be in full control, McCormick says the company has built in more flexibility.

“We have more flex meals, and that gives the customer the opportunity to learn how to make their own meals or go out to dinner and still be following the program and be successful on it,” she says.

Cost

South Beach. If you’re doing your own approach to the South Beach diet, you’ll be doing your own meal planning, shopping and preparation. This can result in significant cost savings when compared to using a meal delivery service. However, the South Beach diet company does offer such a service, with several different plans available. The sliver plan starts at $10.36 per day and includes a four-week Body Reboot Kit, choice of meals and free FedEx shipping. The gold plan starts at $11.79 per day and is the company’s most popular plan. It offers the four-week Body Rebook Kit, a wider selection of meals and foods to choose from and free FedEx shipping. The platinum plan starts at $12.86 per day, and in addition to all the perks of the gold plan, it also includes 20 South Beach Simply Fit shakes that are keto-friendly.

The company’s Diabetes Gold Plan is aimed at helping people with Type 2 diabetes lose weight and better control blood sugars. That plan starts at $11.79 per day. The company also offers a 1-week Body Rebook Kit, which costs $99.99. It’s designed for people with less than 10 pounds to lose and includes specially selected breakfasts, lunches, dinners, snacks and shakes.

Nutrisystem. The four-week basic plan starts at $8.10 per day (for women; $9.20 per day for men). It includes five Nutrisystem breakfasts, lunches, dinners and snacks each week and free FedEx shipping. The top-rated Uniquely Yours program starts at $9.89 a day ($10.99 for men) and includes everything in the basic plan plus a choice of over 160 menu items, unlimited frozen meals and snacks and freedom to pick the frozen and non-frozen foods you want.

The top of the line plan, called Uniquely Yours Ultimate, starts at $10.99 per day ($12.09 for men) and includes all the Uniquely Yours benefits plus seven Nutrisystem breakfasts, lunches, dinners and snacks each week. It's the best option for people who need additional structure and convenience throughout the week. The company also customizes plans for those with diabetes and those who prefer to eat a vegetarian diet. The company often runs incentives to make getting started a little cheaper.

Which Is Better?

The South Beach diet tied for No. 20 overall in U.S. News' 2019 Best Diets rankings. For weight loss, it tied for 17th place. Nutrisystem tied for 23rd place in Best Diets Overall and tied for 12th place in the Best Weight-Loss Diets category.

For faster weight loss, the South Beach diet might be your better option. The diet promises to strip 8 to 13 pounds off your frame within the first two weeks during the restrictive, super-low carb phase. That can jump-start a more sustainable weight-loss effort for some people. For steadier and potentially more sustainable weight loss, Nutrisystem relies on the tried-and-true 1 to 2 pounds weight loss per week standard that the CDC says is healthy.

Because Nutrisystem takes the guesswork out of preparing meals, that can be a big benefit for some people who are either too busy or uninterested in cooking their own food. If you choose to use one of the South Beach diet company’s food delivery plans, you’ll also be freed of having to plan, shop and cook your meals. However, this can also have a downside in that once you’ve reached your goal weight, you may have some difficulty transitioning to a more do-it-yourself approach to long-term maintenance of weight loss.

Though not much long-term data exists about the efficacy of either diet, one 2015 study, published in the Annals of Internal Medicine, found that dieters on Nutrisystem experienced at least 3.8% greater weight loss at three months than the control group.

	South Beach Diet	Nutrisystem
Food	Low-carb, higher protein and higher fat diet that starts out with a very restrictive two-week opening phase that is then liberalized a bit after 14 days.	Low-carb, high-protein ratio.
Weight Loss	Rapid weight loss is possible, but long-term maintenance can be challenging.	Target weight loss of about 1 to 2 pounds per week.
Health Risks	Restrictive approach can be hard to maintain long term.	Restrictive approach can be hard to maintain long term.
Health Benefits	Improved cardiovascular health.	Improved cardiovascular health.
Cost	Average monthly cost for meal delivery plan ranges from $300 to $380.	Average monthly cost about $300. Includes most meals and support/coaching.