The pros and cons of popular diet trends


March 2, 2018

Whole30? Flexitarian? Keto? U.S. News & World Report experts give us a ranking of the best overall diets.


U.S. News & World Report recently revealed its 2018 “Best Diets” list, based on a panel of nutrition experts’ evaluation of 40 plans. They ranked them in helpful categories such as Easiest Diets to Follow and Best Diets Overall. If you want to improve how you eat, take a look at the top diets on the Best Overall list.

The Top 4 Diets

The four-highest ranking diets on this list include the DASH, Mediterranean, Flexitarian and Weight Watchers diets. They scored well because they are flexible and encourage eating nutritious foods from all food groups.

1. The Dietary Approaches to Stop Hypertension Diet — better known as the DASH diet — ties with the Mediterranean diet as No. 1 on the Best Diets Overall list. DASH diet followers can eat any food. The diet’s primary goal is to limit daily sodium intake to less than 2,300 milligrams per day. This sodium limit encourages people to eat fewer packaged or restaurant foods, the primary sources of sodium in our diets. Research shows that this diet helps combat high blood pressure and other health problems. Understandably, healthcare providers promote the DASH diet to their patients. Its emphasis on fruits, vegetables, whole grains and lean meats supports the federal government’s 2015 Dietary Guidelines.

2. The Mediterranean Diet is reminiscent of the DASH diet but is more plant-based, only including meat occasionally. This diet is an ode to the traditional eating style of people living near the Mediterranean Sea. Health professionals highly recommended the Mediterranean diet after years of research show that the Mediterranean diet helps prevent chronic diseases, such as heart disease and diabetes. This is not surprising because the diet emphasizes foods rich in fiber, antioxidants and healthy fats. By eating this way and limiting red meat, sugar and salt, you can be confident that this is a wholesome lifestyle.

3. The Flexitarian Diet is the third highest-ranking diet. Named by combining the words “flexible” and “vegetarian,” this diet is the moral solution for everyone who aspires to be vegetarian but does not want to completely abstain from meat. Because it is primarily vegetarian, these people enjoy the health benefits of a plant-based diet, such as weight maintenance and disease prevention. The flexitarian diet is nutritionally sound and one of the easiest diets to follow, according to the expert panel.

4. Weight Watchers rounds out the top four diets. This popular program offers an in-person support group option, something that many other diets lack. Weight Watchers involves counting SmartPoints as you eat throughout the day. The more sugar or saturated fat a food has, the higher the point value it has. Members try to stay under their daily SmartPoints Budget to drive the weight loss. A point system is not for everyone, but Weight Watchers does emphasize its members free-will and responsibility for their food choices. This educational approach combined with group meetings offer a team-oriented approach to weight loss.

Popular diets that came in last

Have you heard of Whole30, the Dukan diet or the Keto diet?

These diets ranked lowest on the Best Diets list. Why? None of them are long-term health solutions because they rely heavily on rules and forcing people to avoid certain nutritious food (such as dairy and whole grains) without scientific support. People on strict diets can be at risk for nutritional deficiencies and sabotaging feelings of deprivation.

The Whole30 founders advertise the popular Whole30 diet as a 30-day body reset. It promises to help with cravings, hormonal issues and energy levels. To see results, the Whole30 diet says that people must change their eating routine, completely removing nutritious foods such as dairy, grains and legumes. The diet also excludes sugars and alcohol. If you cheat, you must start over from day one. Whole30 simply does not teach the lifelong habits needed for disease prevention and weight loss, nor does it have research to support its claims regarding cravings, hormones and energy.

Whole30 was not the lowest on the list; experts rated the Dukan and Keto diets as less healthy.

The Dukan diet is a four-phase, protein-based diet. The diet only allows certain foods in each phase, often forbidding nutritious foods like grains and fruit. (Notice a theme with the lower-ranking diets?) Major restrictions and complicated sets of rules make this a hard diet to maintain. But don’t worry; the nutrition expert panel did not encourage trying it.

The Keto diet, like the Dukan diet, encourages people to follow a high-fat, low-carbohydrate (carb) path. This is counter-intuitive for your body, which naturally prefers carbs as its primary energy source. Experts voiced concern about Keto diet followers eating excessive amounts of saturated fats and eliminating nutritious, carb-containing food groups such as grains and fruit. If you do not eat many carbs, your body will start using fat for most of its energy. This is an extreme state called ketosis. While this may help you lose weight in the beginning, it is not a long-term solution. A low-carb, high-fat lifestyle is challenging, rigid and, eventually, boring for most people. When you stop the diet, you may still struggle with balancing a variety of foods, potentially causing you to regain your weight. Plus, the diet is not safe for everyone. Pregnant women and people with diabetes, kidney disease and heart disease should talk with a dietitian and physician before considering the diet.

Finding a sustainable, healthy way to eat

Hopefully this article leaves you inspired and encouraged about finding a healthy way to eat that is sustainable for the life. The U.S. News & World Report’s “Best Diets Overall” list is a credible place to start exploring your options. If you were to try any of the Top 10 diets from this list, you would be heading in a good health direction. Be cautious about experimenting with the diets ranked toward the bottom. Look for the diets that are flexible, nutritionally complete, and focused on disease prevention. If you want professional help making a personalized nutrition plan or choosing a diet, consult a registered dietitian.


This post was written by Emily Berg, a 2017-2018 dietetic intern at Vanderbilt University Medical Center. She has a Bachelor of Science in Nutrition-Dietetics and minor in Communication from Auburn University. After becoming a Registered Dietitian, Emily plans to someday open her own private practice to combine her interests in business, counseling, and nutrition.


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Click the links below for more information on these diets:

U.S. News & World Report

The DASH Diet

Mediterranean Diet

Flexitarian Diet