Dear Dietitian: worst diets

Leanne McCrate
Guest Contributor
Plaquemine Post South

Dear Readers,

Last week we discussed U.S. News' rankings of the top 3 diets for overall health, so it seems only balanced to discuss the bottom 3 this week. A panel of nutrition experts evaluated the diets based on seven categories: how easy it is to follow, its ability to produce short-term and long-term weight loss, its nutritional completeness, its safety and its potential for preventing and managing diabetes and heart disease (1).

Coming in at #33 is the Whole 30 Diet. Its claim, although lacking scientific evidence, is that our modern, industrialized food production is the cause of many health problems. In this diet, alcohol, grains, dairy, legumes, and sugar are eliminated for 30 days. On the 31st day, you begin adding foods back to your diet so you can identify the ones that cause digestive distress (2).

#34 is the Keto Diet, a high-fat, low carbohydrate diet. This diet provides quick weight loss in the beginning, and many claim they don't feel hungry because they are filling up on fat, which stays in the stomach longer than carbs. Since you are taking in very few carbs, your body's preferred energy source, your body goes into a state of ketosis where it relies on fat for energy. The fat isn't broken down efficiently in the absence of carbohydrates, producing ketones in the process. Hence, the name Keto.

Bringing up the rear is yet another low carb diet, the Dukan Diet at #35. This diet was created by Dr. Pierre Dukan, a French physician who specializes in weight management. Its premise is that eating protein helps people lose weight, so on this diet you basically eat a lot of meat with non-starchy vegetables. It promises fast weight loss in the beginning and once you've reached your goal, you slowly add bread, cheese and fruit back to your meal plan (3).

The one thing all these diets have in common is that they are all low carbohydrate diets. As I've stated in the past, these diets produce fast weight loss in the beginning by depleting the body's glycogen stores. Glycogen is a form of carbohydrate stored in the muscles and liver that is used for energy in between meals. Water is released when glycogen stores are depleted, resulting in a quick 3-to-5-pound weight loss.

The vast majority of research on nutrition and disease prevention shows that a diet rich in fruits, vegetables, and whole grains, i.e., healthy carbohydrates, is the key to preventing chronic illnesses such as diabetes and heart disease. Therefore, we need more of these foods in our diets to provide better health.

Dear Dietitian does not recommend any of the above diets for weight loss or better health. These diets restrict healthy foods and may result in nutrient deficiencies. Please talk to your doctor or dietitian before beginning a new diet.

Until next time, be healthy!

Dear Dietitian


1. U.S. news best diets: how we rated 35 eating plans (2020, January 2). Retrieved from

2. Whole30 (2019). Retrieved from

3. Spritzler, Franziska. The Dukan diet review: does it work for weight loss? Dec 12, 2018. Retrieved from

Leanne McCrate, RDN, LD, CNSC, is an award-winning dietitian based in Missouri. Her mission is to educate consumers on sound, scientifically-based nutrition. Do you have a nutrition question? Email her today at Dear Dietitian does not endorse any products, health programs, or diet plans.