What Is the 17-Day Diet?

Woman chopping vegetables in her kitchen

Getty Images 

In This Article

The 17-day diet promises quick weight loss—10 to 15 pounds over the first 17 days—through a restrictive first phase that eliminates sugar, grain-based foods, fruit, and most dairy foods. This will rev up your metabolism and encourage your body to burn fat, the diet's physician creator claims.

Realistically, you'll likely lose some weight on the 17-day diet, particularly in the first phase of the program. The diet gets slightly less restrictive in its next 17-day phase, and ultimately adds back many of the foods it eliminates. If you're not careful, this can lead you to regain some or all of that initial weight lost.

What Experts Say

"The 17-Day Diet progresses through four stages, claiming to rev your metabolism. Experts say there’s little evidence for the 17-day switch, or for some of the diet rules like no fruit past 2pm. But calorie restriction should lead to weight loss, and the later stages are balanced."

Chrissy Carroll, RD, MPH

Background

The 17-day diet is the brainchild of Michael Moreno, M.D., a family practice physician at Kaiser Permanente, who originally wrote the book The 17-Day Diet and published it in 2010. Dr. Moreno updated his blueprint for weight loss in 2014 with The 17-Day Diet: Breakthrough Edition, adding recipes plus information about supplements and exercise.

The diet peaked in popularity in the early 2010s but still garners a steady stream of new followers to join its long-term devotees. Dr. Moreno hosts a detailed diet website with information, resources, and recipes for newbies and for those who have followed the program for a while.

Proponents of the diet tout its fast results (especially in the first 17 days, which is less than three weeks) and its ease of implementation and use. However, as with any diet, it's tricky to get sustained results, and people who have followed the 17-day diet say it's difficult to follow long-term.

How It Works

The 17-day diet actually has four phases, or "cycles," the first three of which are 17 days long. According to Dr. Moreno's book:

  • Cycle 1 ("Accelerate") is designed to "promote rapid weight loss by improving digestive health. It helps clear sugar from the blood to boost fat-burning and discourage fat storage." This cycle reduces carbohydrate intake slightly but eliminates all sugar, sweets, and refined carbohydrates such as bread and pasta, replacing them mainly with low-carb vegetables. You're allowed to have some fat in the form of olive oil or flaxseed oil, plus "liberal amounts" of lean protein. Probiotic foods such as yogurt, kefir and tempeh also are encouraged.
  • Cycle 2 ("Activate") is designed to "reset your metabolism through a strategy that involves increasing and decreasing your caloric consumption to stimulate fat burning and to help prevent plateaus." On this cycle, you'll alternate days between the more restrictive Cycle 1 foods and the less restrictive Cycle 2 foods. On "Cycle 2" days, you can have everything that was allowed in Cycle 1, plus some higher-fat meats and fish, some whole grains, some starchy vegetables, and legumes.
  • Cycle 3 ("Achieve") is designed to help you "develop good eating habits through the reintroduction of additional foods and move you closer to your goal weight." Cycle 3 foods include all foods from the first two cycles, plus some additional fattier types of meat (quail and turkey bacon, for example). You also can have some forms of whole-grain breads, high-fiber cereals, and whole-grain pastas. Vegetables are unlimited, while you can have two servings of fruit daily. You also can add alcoholic beverages in moderation.
  • Cycle 4 ("Arrive") is designed to "keep you at your goal weight through a program of eating less that lets you enjoy your favorite foods on weekends while eating healthfully during the week." This cycle, which is open-ended, calls for eating only foods allowed in the first three cycles during the week and then giving yourself some leeway to splurge on one to three meals and some alcohol between Friday dinner and Sunday dinner.

The program also includes "transitional day fasts," which are supposed to "coax your body into additional fat-burning between cycles." These fasts are optional, according to Dr. Moreno.

If you decide to follow the 17-day diet, you'll likely find that many (or even most) of your favorite foods are off the table for the duration. This is a feature, not a bug, proponents say because it accelerates your weight loss. But you may find it makes the diet tricky to follow when eating or socializing with friends and family.

What to Eat

Compliant Foods

  • Fish and low-fat poultry (Cycle 1)

  • Shellfish and higher-fat poultry (Cycle 2)

  • Poultry bacon and sausage (Cycle 3)

  • Red meat and pork (Cycles 2 and 3)

  • Eggs (all cycles)

  • Non-starchy vegetables (all cycles)

  • Starchy vegetables (Cycles 2 and 3)

  • Legumes (Cycles 2 and 3)

  • Whole grains (Cycles 2 and 3)

  • Probiotics (yogurt, kefir, sauerkraut) (all cycles)

  • Low-sugar fruit (apples, berries, pears, citrus) (all cycles)

  • High-sugar fruit (bananas, mango, pineapple) (Cycle 3)

Non-Compliant Foods

  • Milk, ice cream, and most other dairy products (all cycles)

  • Foods with added sugar

  • White bread (and other highly processed bread products)

  • Alcohol (allowed in moderation)

  • Candy

  • Wheat flour-based pasta

  • Dried fruit

  • Flavored coffee drinks

  • Juice

The 17-day diet focuses on eliminating certain carbohydrates from your meals. Therefore, you'll tend to eat more protein than you might normally while eliminating entire groups of carb-based foods.

Protein

There are plenty of protein options on the 17-day diet, even starting in the diet's first cycle. From day one, you can enjoy fish (including salmon, sole, flounder, catfish, tilapia, and canned light tuna in water). You also can have chicken and turkey breast, lean ground turkey, and eggs in limited quantities. In the second cycle, you can add shellfish, pork, lean red meat, lamb and veal. and in the third cycle, you can have fatty types of poultry plus turkey bacon, turkey sausage, and Canadian bacon.

Vegetable

When it comes to vegetables, the 17-day diet breaks them down into starchy and non-starchy vegetables. Non-starchy vegetables, which Dr. Moreno calls "cleansing vegetables," are allowed in unlimited quantities. They include cauliflower, cabbage, broccoli, Brussels sprouts, asparagus, celery, green beans, greens, mushrooms, onions, and tomatoes. Starchy vegetables are allowed beginning in Cycle 2. They include corn, potatoes, pumpkin, sweet potato, and winter squash.

Fruit

Fruit is divided into "low-sugar fruit" and "high-sugar fruit." Two servings per day of low-sugar fruit are allowed from the first cycle, while high-sugar fruit isn't allowed until the third cycle. Low-sugar fruit includes: apples, berries, grapefruit, oranges, peaches, pears, plums, prunes, and red grapes. High-sugar fruit includes: apricots, bananas, cherries, figs, kiwi, mango, papaya, pineapple, tangelo, and tangerines.

Grains

The diet bans grains and other "natural starches" in Cycle 1, but then allows them (limited in types and quantities) in Cycles 2 and 3. In Cycle 2, you can add: amaranth, barley, brown rice, couscous, cream of wheat, grits, long grain rice, millet, oat bran, old-fashioned oatmeal, and quinoa. In Cycle 3, your grain-based options expand dramatically, with: whole-grain and gluten-free breads, high-fiber cereals, plus various pastas (whole wheat, gluten-free, vegetable-based and high-fiber).

Dairy

Dairy products are allowed in extreme moderation on the 17-day diet. In Phases 1 and 2, people following the program are encouraged to have two servings per day of probiotic foods, which include yogurt, kefir, and acidophilus milk, along with Breakstone Live-Active cottage cheese (cottage cheese with active cultures). In Phase 3, they can add small amounts of certain cheeses (Brie, camembert, fontina, low-fat cheddar, Edam, feta, goat, Limburger and part-skim mozzarella). They also can enjoy low-fat cottage cheese, low-fat milk, and low-fat ricotta cheese.

Fats

When it comes to fats, Dr. Moreno encourages people following his program to consume one to two tablespoons of "friendly fats" (olive oil and flaxseed oil) from the first day. Once they get to Cycle 3, they also can have a small amount of avocado, canola oil, walnut oil, mayonnaise, nuts or seeds, reduced calorie margarine, and salad dressing per day.

Recommended Timing

The 17-day diet program includes three meals per day plus snacks. The goal is to keep people who are following the diet from getting hungry. From the first cycle, you can eat as much as you want of specific proteins and the so-called "cleansing" (e.g., non-starchy) vegetables.

The diet blueprint includes suggested meal plans for all days, although you can mix and match those plans to suit your own tastes. You also can elect to do fast days in between 17-day cycles (in which you'll consume smoothies) to jump-start your weight loss.

Resources and Tips

To follow the 17-day diet, it's helpful (although not required) to purchase Dr. Moreno's book, which includes meal plans and recipes along with the diet blueprint.

Still, most meal templates are simple. For example, a typical breakfast in Cycle 2 includes one cup of lean granola with 6 oz. no-sugar-added fruit-flavored yogurt, while a typical dinner would feature garlic shrimp, steamed green beans, and a large tossed salad dressed with 1 tablespoon olive oil.

If you choose to do the transitional day fasts, you'll need to consume smoothies in three liquid meals on your fasting days. The smoothies contain: almond milk, yogurt, whey powder, powdered fiber, plus fruit.

Modifications

Following the 17-day diet if you have food allergies or intolerances should be relatively simple—you'll just need to eliminate foods you can't have. For those with nut or dairy allergies, it's easy, since those foods are mostly not included in the diet blueprint. It's also easy to follow the diet if you're gluten-free since it mentions when you can have foods such as gluten-free bread and gluten-free pasta.

The 17-day diet may be more difficult to follow if you're a vegetarian or vegan since it relies heavily on poultry- and fish-based protein, especially in the first two cycles.

If you have diabetes or another chronic health condition, you should speak with your doctor prior to starting any diet program, including the 17-day diet. The program can be safe for those with health concerns, but you'll want to make sure you're getting all the nutrients you need.

Pros and Cons

Pros

  • Diet relies heavily on healthy vegetables and lean protein

  • Easily accommodates dietary restrictions

  • Followers are likely to lose weight, especially at first

Cons

  • May not have enough fiber, particularly in beginning

  • Difficult to follow long-term

  • Requires lots of food prep and meal planning

Pros

The 17-day diet's cycles include loads of healthy non-starchy vegetables and lean protein. In fact, you're allowed to have unlimited amounts of both in all phases of the diet. These should help prevent hunger in the diet's early days.

If you have dietary restrictions, such as celiac disease, a dairy intolerance, or a nut allergy, it's no problem to adopt the program to meet your needs. Food choices are expansive enough so that you can steer clear of allergenic items and still follow the diet.

You're almost certain to lose a significant amount of weight, especially in the diet's early days. That's because your calories will be pretty limited, even though you can have unlimited lean protein and non-starchy vegetables. So you'll notice results on the scale and in the mirror quickly, which may help to keep you motivated.

Cons

Everyone needs fiber—in fact, dietary guidelines recommend we get upwards of 25 grams of fiber per day. You'll be hard-pressed to get that much fiber on the 17-day diet without taking a fiber supplement since the program eliminates or limits many high-fiber foods.

The 17-day diet will be difficult to follow long-term, simply because it's so different from the way many of us eat normally. You won't be able to grab a snack (unless it's fruit) or eat a conventional meal out. It also requires a fair amount of food preparation—even though the recipes and meal plans are fairly simple, you'll still need to cook everything.

How It Compares

The 17-day diet is similar to other diets that emphasize cutting carbohydrates, as opposed to counting calories or avoiding fat. If you follow the 17-day diet program, you're likely to lose weight. However, the plan doesn't match up well to generally accepted nutritional guidelines.

USDA Recommendations

The U.S. Department of Agriculture, in its ChooseMyPlate nutritional guidelines tool, recommends that you fill more than one-quarter of your "plate" (as in your daily diet) with grains—ideally with whole grains. The 17-day diet, of course, doesn't allow any grains in its first cycle, and after that only allows a very limited amount of grain-based products.

ChooseMyPlate also calls for more fruit and more dairy than the 17-day diet, along with less protein than Dr. Moreno's program. Finally, the USDA's ChooseMyPlate encourages people to consume more calories than you'd consume on the 17-day diet.

Similar Diets

Atkins Diet

Although it's undergone some significant changes over the years since it first was introduced, the Atkins diet remains the most popular low-carbohydrate diet. Like the 17-day diet, the Atkins diet allows unlimited quantities of protein and green vegetables in its first phase (although the details vary between the diets). And like the 17-day diet, the Atkins diet gradually reintroduces more and more higher-carb foods as you progress through its stages.

South Beach Diet

The South Beach diet, another lower-carbohydrate diet program, deletes added sugar from your plate, just as the 17-day diet does. The first phase of South Beach is quite similar to the first cycle of the 17-day diet: you'll eliminate grain-based foods, fruit, starchy vegetables, and alcohol. As in the 17-day diet and the Atkins diet, you'll add those foods back (in smaller quantities) in later stages of the South Beach diet. South Beach also limits dairy products, but the dairy foods that are allowed are different than those on the 17-day diet.

Beyond Diet

This program, developed by a certified nutritionist, also features an approach that's lower in carbs and quite restrictive, especially at first. It also promises significant weight loss. The Beyond diet, however, requires that you purchase proprietary products to follow the program, while the 17-day diet does not.

A Word from Verywell

Choosing a diet program is a very individual decision, and what's right for you may not be right for your friend or relative. If you're looking for a program that will create quick results—which can help with motivation—then the 17-day diet could be on your shortlist. However, you should talk to your doctor before you start any diet program, to make sure the program you've chosen will mesh well with other health concerns you may have.

Was this page helpful?

Article Sources

Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  • Moreno, Mike. The 17 Day Diet Breakthrough Edition. Simon & Schuster, 2014.