A Breakdown of Popular Diets

by Natalie Digate Muth, MD, MPH, RD on May 01, 2015

The following chart offers a quick reference to some of the most popular diets. Use it to help you guide clients toward the best eating plan choices for them.

THE DIET DESCRIPTION PROS CONS
Atkins® low carbohydrate | calories not specified | induction phase with very low carbohydrates (20 g) and then gradual increase early weight loss | well studied with demonstrated benefit | recipes simple to prepare | good satiety and taste difficult to sustain | nutritionally deficient, especially in fiber and fruits | high in saturated fat
Biggest Loser® balanced | individual calorie targets | Adherents choose a Biggest Loser book to follow for instructions. emphasizes fruits, vegetables, lean protein and whole grains | discourages added sugar and solid fats | encourages home cooking | Exercise is a key piece of the program. Association with television show may create unrealistic expectations.
DASH (Dietary Approaches to Stop Hypertension) balanced | calories based on individual needs | high in fruits and vegetables | low sodium developed to reduce blood pressure well studied with clear health benefits | relatively easy to follow, with information and meal plans available for free (www.nhlbi.nih.gov/files/docs/public/heart/hbp_low.pdf) may require retraining of taste buds, due to low sodium content
Gluten-Free balanced | calories not specified | eliminates all foods that contain gluten (wheat, barley, some other grains) treats celiac disease and may help those who believe they
have gluten sensitivity
not in itself associated with weight loss | poorly studied for those without celiac | Elimination of gluten could interfere with workup and diagnosis of celiac disease.
Jenny Craig® balanced | individual calorie targets between 1,200 and 2,000 | Followers purchase prepackaged meals and snacks and go to a Jenny Craig center for weekly counseling, or sign up for an at-home plan. Prepackaged foods make adherence easier initially. | meals well accepted by most people | behavioral support from peer consultant prepackaged foods very expensive and hard to sustain | does not allow for home-cooked and restaurant meals | Peer consultants are not health professionals.
LEARN (Lifestyle, Exercise, Attitudes, Relationships, Nutrition) balanced | calories not specified | emphasizes lifestyle changes to promote weight loss and health incorporates critical aspects of weight loss other than nutrition | self-taught | effective for long-term weight loss maintenance | promotes lifestyle change | well studied Initial weight loss may come slowly.
Low Glycemic Index balanced | calories not specified | a diet rich in “good carbs” (low glycemic index) emphasizes whole foods and minimizes processed foods difficult to know glycemic index of all foods | Studies show mixed results.
Medifast® balanced | very low in calories (800–1,000 per day) | five 100-calorie meal replacement shakes and Medifast products per day, plus one meat and vegetables entrée per day Caloric restriction promotes quick weight loss. | nutritionally sound and balanced Because of the very low calorie levels, followers should have medical supervision. | difficult to sustain | minimal amounts of “real” food (uses powdered + water)
Mediterranean balanced | calories not specified | emphasizes produce, nuts, healthful oils and minimal red meat, sugar and saturated fat; red wine in moderation clearly has myriad health benefits | incorporates physical activity and exercise requires planning | may be more expensive than typical meals
Nutrisystem® balanced | calorie targets of 1,200–1,550 | Followers purchase prepackaged meals online and shop for vegetables and fruits to supplement them. Prepackaged foods make adherence easier initially.
| behavioral support in online group environment
prepackaged foods expensive and hard to sustain | does not allow for home-cooked and restaurant meals
Ornish low fat | calories not specified | rates foods as most (1) to least (5) healthful with emphasis on fruits, vegetables and whole grains group sessions for behavioral support | strong evidence for cardiovascular benefits | emphasizes exercise difficult to sustain | can be expensive
Paleo® low carbohydrate | calories not specified | Adherents aim to eat the way hunters and gatherers did, with no refined sugar, dairy, legumes or grains.
Emphasis is on meat, fish, poultry, fruits and vegetables.
discourages heavily processed and refined foods restrictive, which may lead to nutrient insufficiencies | not studied | expensive
Pesco-Vegetarian balanced | calories not specified | no meat or poultry; includes fish nutritionally balanced if well planned | heart healthy | Inclusion of fish provides additional benefit due to high health value of fish, especially oily/fatty fish. if not well planned, may have some nutrient insufficiencies, especially iron | People may miss meat.
South Beach® low carbohydrate | calories not specified | Initial low-carb phase relies on low-glycemic-index and high-protein foods, plus moderate
intake of mono- and polyunsaturated fats; gradually adds back “healthy” carbs.
differentiates healthful and less healthful carbohydrates | overall, healthy and balanced after first phase restrictive first phase | encourages too much initial weight loss | lot of time required for food preparation | not well studied
Therapeutic Lifestyle Changes (TLC Diet) low fat | weight loss calorie goals of 1,600 for men and 1,200 for women developed to decrease cholesterol effective at improving cholesterol | well studied | incorporates physical activity requires reading nutrition labels to meet saturated-fat and cholesterol goals
Vegan balanced | calories not specified | no meat, fish, poultry, eggs or dairy rich in high-fiber foods | provides health and environmental benefits very restrictive | risk of nutrient insufficiencies, especially iron and vitamin B12
Vegetarian balanced | calories not specified | no meat, fish or poultry nutritionally balanced if well planned | heart healthy if not well planned, may have some nutrient insufficiencies, especially iron | People may miss meat and fish.
Volumetrics balanced | calories not specified | emphasizes eating foods with low energy density (few calories relative to nutrient value/fullness) no food restrictions | filling | emphasis on vegetables and fruits may be hard to sustain, especially for people who don’t like fruits and vegetables
Weight Watchers® balanced | individualized calorie targets | tracks daily points (each point = approx. 50 kcal) based on current weight and weight goals good variety of foods | behavioral support | lots of education | not too restrictive | well studied with clear efficacy appeals to a specific audience | too costly for some | counselors, not health professionals
Zone® balanced | individual calorie targets | active weight loss targets of 1,200 calories for women and 1,500 calories for men lower in saturated fat than Atkins | recipes simple to prepare | effective in short term poor long-term adherence at least partly due to very low calorie allowance | restricts many nutrient-dense foods

To read more about talking to your clients about diets, please see "What’s the Best Diet for Me?" in the online IDEA Library or in the March 2015 print issue of IDEA Fitness Journal. If you cannot access the full article and would like to, please contact the IDEA Inspired Service Team at (800) 999-4332, ext. 7.

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About the Author

Natalie Digate Muth, MD, MPH, RD

Natalie Digate Muth, MD, MPH, RD IDEA Author/Presenter

Natalie Digate Muth, MD, MPH, RD is a board-certified pediatrician, registered dietitian, and ACE Health Coach. She is committed to providing evidence-based nutrition and fitness information to health professionals and consumers alike in a way that is logical, practical and directly applicable to readers’ lives. She has authored over 100 publications and book chapters, all which are based on the latest scientific evidence and presented in a manner that is easy-to-understand and apply. She is Director of Healthcare Solutions for the American Council on Exercise (ACE) having written the nutrition chapters for each of ACE’s textbooks, the ACE Fitness Nutrition Manual and Specialty Certification, and recorded several Webinars and online courses. Furthermore, as a spokesperson for ACE, the largest fitness certifying and advocacy organization in the country, she informs broadcast and print media outlets throughout the U.S. on pertinent nutrition and fitness issues. She is author '"Eat Your Vegetables!" and other mistakes parents make: Redefining How to Raise Healthy Eaters'. She presented a similar topic at IDEA World 2009; the video is available for purchase through IDEA. Certifications: ACE, ACSM and NSCA