The 3 Most Popular Diet Plans: What's the Science and What to Expect

If you’re one of the millions of Americans who have tried countless diets but haven’t been able to lose the weight and keep it off, it can feel like nothing will ever work. 

If you’re one of the millions of Americans who have tried countless diets but haven’t been able to lose the weight and keep it off, it can feel like nothing will ever work. 

But real, positive change is possible - with the right plan.

We’ve brought you the top three diet plans that promise healthy, manageable weight loss. Read on to get an idea of what to expect from each, and what you’ll have to do in order to reach your goals.

The Mayo Clinic Diet

The Mayo Clinic Diet focuses on creating a lifetime of healthy eating habits. The program helps you overcome personal and emotional reasons behind unhealthy eating, in a very supportive environment.

What’s the Science

Using their unique food pyramid as a base, dieters are encouraged to eat lots of fruits, veggies and whole grains, and to get moving more. It’s less of a revolution and more of a supportive, manageable method for eating healthy, and keeping your weight loss goals on track.

What You Get

Mayo Clinic does not provide prepackaged meals or snacks. Instead, their helpful resources guide dieters through the two-part program: "Lose it!" and "Live it!"

There’s no counting calories (the diet relies more on an understanding of proper portioning) and no food group is off-limits.

Some of the rules during phase 1: no eating while watching TV, no sugar (except for fruit) no snacking (except on fruits and veggies).

Phase 2 is there to teach lifelong healthy eating habits by focusing on proper serving size, meal planning, the basics of nutrition and helpful tips to stay motivated.

How Easy is it to Maintain

This program is probably the easiest of the three to maintain, as it does a great job of teaching positive lifelong eating habits. It’s less a diet and more a way of life, and a constant resource to help you if you’ve fallen off track.

Visit The Mayo Clinic Diet >>


NutriSystem simplifies dieting by taking care of meal planning and prep. No counting calories or cooking. Simply eat 6 small meals throughout the day - delivered by Nutrisystem - and lose weight.

What’s the Science

Nutrisystem is built around portion control and the idea that eating small meals throughout the day keeps the metabolism working hard, cravings at bay and energy high.

What You Get

Nutrisystem delivers prepackaged meals and snacks that include entrees, shakes and protein bars.

The program aims to provide healthier versions of the comfort foods we all love - like breakfast burritos and flatbread pizza - making the dieting easier to stick with. Their menu has something for every taste bud, with over 150 entrees and snacks to choose from.

They also offer gender-specific plans and senior, diabetic and vegetarian plans.

How Easy is it to Maintain

It can be difficult eating prepackaged meals every day. While these meals are supplemented with fresh fruits and vegetables, strong willpower is required to sit at the dinner table with your family and not eat what everyone else is eating.

One “flex” meal per week provides room to eat out or test one of the many recipes on the Nutrisystem site.

Once you’re ready to wean yourself off the program, support staff is on hand via phone or chat to help you maintain your new weight.

Visit Nutrisystem >>

South Beach Diet

The South Beach Diet is a three-phased diet program designed to reset your metabolism for better weight loss results.

What’s the Science

By replacing bad carbs and sugars with good ones, and following a high protein diet, dieters will slim down without feeling deprived.

What You Get

During phase 1 you’ll receive weekly prepared meals, which are high in protein and low in sugar and refined carbs. The weight is supposed to come off fast, because you’ve essentially trained your body to burn fat instead of sugar and carbs.

Phase 2 is less restrictive. You’ll continue to receive prepared meals, but you’ll also add in good carbs, whole grains and fruit.

Phase 3 is when you set out on your own - no prepared meals from this point on. The website is available with a lot of tools to encourage dieters to keep the weight off - like recipes, fitness trackers, and support staff on hand to answer any questions.

How Easy is it to Maintain

The South Beach mantra is “Burn Fat without Hunger.” The hard part, as in most diets, is in the beginning. Getting used to a new eating plan takes some time - especially when the carbs and sugars of snacks and comfort foods are eliminated.

Yet, there’s proof in numbers; Over 11 million people have lost weight with the South Beach Diet. And maybe you can too. 

Visit South Beach >>


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*The information on this site is based on research, but should not be treated as medical advice. Before beginning any new diet plan, we recommend consulting with a physician or other professional healthcare provider. Results may vary based on various health factors, individual weight loss plans and adherence to the meal plan.