A grueling diet beloved by Instagrammers cuts out everything from alcohol to dairy - here's how well it works

The first: Absolutely no alcohol all 30 days. This includes cooking with wine. Whole30 is meant to be a kind of radical body cleanse, and for that reason, the inventors also ask people to refrain from smoking during the 30 days of the fast. 

Eating whole grains can be a great way to incorporate belly-filling fiber and satisfying protein into your diet, all while reducing inflammation. But forget about it if you're doing Whole30. 

Just about every kind of starch, bran or germ you can think of is off-limits. Gluten-free bread, buckwheat flour, amaranth or rice? No, no, no and no. 

However, potatoes, which were formerly banned from the diet, are ok for Whole30-ers now. (Still, no potato chips or french fries allowed.) 

That includes less obvious sweets, too, like honey, agave and maple syrup.

Sugar replacements like stevia, Splenda and Equal are also not allowed.

The point of the diet is to upend your bad eating habits completely, not just replace one treat for another treat-substitute.

In general, these are cheap, fiber-rich protein sources, however.

There's no dairy on the plan, either. You won't be getting any gut-friendly yogurt cultures or probiotics this month.

Carrageenans can cause inflammation, and there's some evidence that MSG can trigger headaches.  

Whole30 also says that sulfites are banned from the diet, but dieters are still allowed to season with balsamic vinegar and cook eggs, even though both of those contain sulfites. (Sulfite sensitivity is a fairly rare condition, affecting between 1 in 20 and 1 in 100 asthmatics.)

In fact, there are several ways that Whole30 lets you break its strict regime: clarified butter is ok, though real butter is not, and iodized table salt, which contains some sugar is allowed. It's not clear why Whole30 made these exceptions, but without them the diet would be extremely hard to follow. 

You aren’t allowed to weigh yourself and you don’t need to count calories on the diet.

That’s a strange strategy because regular weigh-ins are generally considered a helpful way to maintain a healthy weight for the long haul.

Anything you enjoyed eating before that you don't think is "psychologically healthy" for your diet isn't a good idea, according to Whole30. 

The premise is that by severely restricting what you eat for a month, you're clearing out your system and figuring out what causes inflammation, while also changing your relationship with food.

"A pancake is still a pancake, even if it is made with coconut flour," as the Whole30 crew says. 

The Whole 30 website even admits the basic mantra of the program is restriction: "When in doubt, leave it out. It’s only 30 days."

Ideally, your diet is going to consist of a lot of fresh veggies and meats. 

The Whole30 site says simply: "We had to draw the line somewhere."

The diet allows a little fruit juice to flavor sauces, soups, and entrees. But drinking a glass of fruit juice is not in the spirit of the diet, and juice has less nutritional value than a piece of fruit, so don't think you're going to sip your way through the month.

Research tells us that with the notable exception of Vitamin D, it's probably better to get those things in foods, not pills. 

But you'll probably be preparing a lot more food at home, and not drinking, which may help balance out the cost of buying extra meats, fish, and fresh fruit. 

If everyone in the world decided to embark on the Whole30 diet, we'd all be pretty hungry. There simply aren't enough eggs, meat, and fish to go around when we're not eating other protein sources. 

At some point, your willpower is probably going to break a little.

So a harsh slap on the wrist probably isn't the most effective way to improve your diet over the long term.

Dietitian Jessica Penner isn't a fan: "The Whole 30 is a short-term solution to a long-term problem," she writes on her website.

The idea is that you pay attention to how you feel as you begin adding more foods to your plate, and limit those that make you feel inflamed and sluggish.

Nutrition experts caution that 30 days may not really be enough for your body to re-set, though. 

"In a clinical setting, we put patients on these sorts of restrictive diets for three months, because the immune system needs three months to shut off," Alessio Fasano, director of the Center for Celiac Research and Treatment at Massachusetts General Hospital, told Time. "Thirty days isn’t enough time to turn off systemic inflammation." 

Most nutritionists agree that plant-based diets centered around veggies, whole grains, and lean proteins (like beans) are the way to go. 

Especially because after the 30 days are up, you're largely on your own to decide how to add a whole plethora of banned foods, — including bread, beans, and cheese — back in to your regular diet.