Thinking of trying the Whole 30 diet? Here's what dietitians want you to know

This diet eliminates foods that could be triggering health issues, then slowly reintroduces them. Here’s how it works — and what experts think.
Arrangement of raw meat and produce
“You might not need to eliminate all of the foods that are eliminated on Whole 30," said Samantha Cassetty.Getty Images

You’ve probably seen someone you follow on Facebook or Instagram posting photos of their Whole 30 meals. It’s a popular diet. More than 710,000 people like the official Whole 30 Facebook page, and 863,000 people follow Whole 30 on Instagram.

The meals they post look healthy and pretty — you see lean proteins like shrimp and chicken breast. Veggies are front and center. Green is a dominant color. So what is the Whole 30 diet plan all about?

On the Whole 30 diet, you eat certain whole foods for 30 days. (Get it?) It was co-founded in 2009 by Melissa Urban and her ex-husband Dallas Hartwig.

How does the Whole 30 diet work?

Whole 30 is an elimination diet. By following the Whole 30 diet rules and not eating foods that might contain common allergens or trigger inflammation, you can see how your body responds. That means no cheating — you’re expected to follow the program to the letter for 30 days.

Whole 30 is a diet in the traditional sense — it tells you what you can and can’t eat,” Karen Ansel, a New York-based registered dietitian and author of “Healing Superfoods for Anti-Aging,” told TODAY.

After 30 days, you systematically reintroduce the forbidden food groups and pay attention to how they make you feel.

You can eat what you like from the allowed foods — you don’t have to count calories. While people may turn to Whole 30 to lose weight, with Whole 30, weight loss is not the main goal. In fact, you’re supposed to stay away from the scale while you’re following Whole 30.

What does the research say about the Whole 30 diet?

Samantha Cassetty, a registered dietitian based in New York City and the coauthor of “Sugar Shock,” told TODAY that there’s no scientific evidence to support the health claims made by the Whole 30 diet, and it wasn't designed by a credentialed expert. In fact, there’s little independent research that specifically evaluates the Whole 30 diet. Anecdotally, people who have tried it share testimonials that it has helped them with a wide range of health conditions.

“I know people who have tried it, and I don’t discount anybody’s personal experience,” Cassetty said. The diet can make you aware of how much processed food or added sugar you’re consuming, or how you’re interacting with alcohol. “When you come off it you can be more thoughtful about those types of things,” Cassetty said.

But the diet eliminates a lot of foods that are generally considered healthy. “My concern with Whole 30 is that there’s a long list of what you cannot have, and that includes foods that are linked to good health in many ways,” Ansel said. “When people are cutting out entire food groups, that’s always a big red flag.”

Ansel is especially concerned that the diet doesn’t allow:

  • Grains, since whole, minimally processed grains are good for our guts
  • Beans and legumes, which are good sources of fiber
  • Dairy, which contains calcium to support bone health

And she also worries that a 30-day diet can set you up for yo-yo dieting. Cassetty agrees: “I think phase diets get such a bad rap because people put their lives on pause to do something for a short period, then go back to eating what they used to before. Whatever benefits they experienced are immediately canceled out the minute they resume their former eating patterns.”

Is Whole 30 a good choice for you?

“I think it’s overly restrictive,” Cassetty said. If you want to try a new way of eating, she recommends making small, sustainable, healthy changes like cooking at home more often and eating more vegetables.

You might be considering the Whole 30 diet if you suspect the food you eat is affecting how you feel. There are times when an elimination diet is appropriate, Cassetty said. But an elimination diet should be done under the guidance of a dietitian, for a specific reason. “You might not need to eliminate all of the foods that are eliminated on Whole 30. If you’re having some problem, the goal is to eliminate as few foods as possible,” Cassetty said.

“Foods like tofu, whole grains and pulses can absolutely fit into a long-term healthy eating plan,” Cassetty said. She pointed to the DASH diet, Mediterranean diet and MIND diet as good long-term options. “The people in the Blue Zones, who are living the longest disease-free lives, aren’t doing the Whole 30.”

What do you eat on the Whole 30 diet?

On the Whole 30 diet, you eat a whole-food-focused diet. Whole 30 recipes include Whole 30-approved foods like:

  • Meat, seafood and eggs
  • Vegetables and fruit
  • Natural fats, such as olive oil and coconut oil
  • Some nuts and seeds
  • Herbs, spices and seasonings
  • Black coffee

The Whole 30 meal plan eliminates foods that could trigger allergies, reactions or inflammation. That means these foods won’t make it onto your Whole 30 shopping list:

  • Added sugar and artificial sweeteners
  • Alcohol
  • Grains
  • Most legumes, including beans, peanuts and soy
  • Dairy
  • Carrageenan, MSG or sulfites
  • Baked goods or junk food, even if they are made with approved ingredients

Whole 30 meals are built around one to two palm-sized protein sources, with the rest of your plate filled with vegetables. Healthy fats are included in recommended amounts. You can include fruit occasionally. On Whole 30, snacks are allowed, but not recommended — waiting three to five hours between meals is preferred. You can find information, resources, support and easy Whole 30 recipes at Whole30.com.

Following the Whole 30 diet, in a typical day you might eat:

The Whole 30 diet is similar to:

  • Paleo diet, which can allow some unrefined sugar, Paleo-compliant treats and alcohol
  • Keto diet, which allows dairy but limits fruit
  • Atkins diet, which limits but doesn’t eliminate grains, legumes and sugar
  • 30 Clean, where you join a private Facebook group for a 30-day healthy eating challenge

Is the Whole 30 diet effective long-term?

Whole 30 isn’t intended to be a long-term diet. By evaluating how you feel before and after Whole 30, it’s designed to help you become more mindful about your eating habits and to help you identify foods that are troublesome for you.

Talk with your doctor before starting the Whole 30 diet or any other diet — your doctor can recommend the best eating plan for you, based on your health needs.