17 Day Diet: Diet Review

By Kathleen M. Zelman, MPH, RD, LD
WebMD Expert Review

If diets that promote the same approach day in and day out bore you, The 17 Day Diet may be for you.

The 17 Day Diet is actually three cycles, each lasting 17 days, plus a fourth long-term maintenance cycle. Whether you are looking to lose 10 or 100 pounds, this plan can help you lose weight quickly, avoid the dreaded plateaus, and revamp your metabolism, says author Michael Moreno, MD.

"Everyone wants fast results and the calorie confusion of this plan burns fat, achieves weight loss results, and helps dieters avoid boredom," says Moreno, a family medicine doctor at Kaiser Permanente in San Diego.

The 17 Day Diet: What It Is

Cycle 1, called "Accelerate," strips your diet down to the bare bones of approximately 1,200 calories per day. It promises weight loss of 10-15 pounds, most of which is water weight.

"This phase cleanses, hydrates, removes unhealthy carbs, improves unhealthy eating habits, and stimulates fat metabolism," Moreno says.

In cycle 2 (called "Activate,") the food plan is alternated with a slightly higher-calorie activate plan. Moreno says the zig-zag between cycles keeps the metabolism guessing, helps prevent boredom, and continues to stimulate fat burning to yield about a 5-6 pound weight loss.

Cycle 3, called "Achieve," is the stabilization period that allows healthier foods with a slower rate of weight loss of about 2-3 pounds, Moreno says.

Cycle 4 -- the final phase, called "Arrive" -- is when you arrive at your goal weight. In cycle 4, follow meal plans from one of the earlier cycles during the week with controlled splurges on weekends to maintain your new weight.

Exercise at least 17 minutes a day during the first two cycles -- primarily walking because of the limited calorie intake. In the later cycles, ramp up exercise to 150-300 minutes per week for continued weight loss.

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The 17 Day Diet: What You Can Eat

The 17 Day Diet promotes a diet of clean eating, devoid of sugar, processed foods, fried foods, and other unhealthy foods.

Cycle 1 allows an unlimited amount of nonstarchy vegetables and lean protein (including 2 eggs per day, if you have normal cholesterol level), along with limited amounts of fruits, probiotics (such as yogurt), and a little bit of "friendly" fat, such as olive oil or flaxseed oil.

Registered dietitian Melissa Nodvin, MS, RD estimates this plan to be about 1,200 calories per day, or the minimum recommended calorie level.

Here is a sample day's plan from Cycle 1:

  • Unlimited lean protein

  • Unlimited nonstarchy vegetables

  • 2 low-sugar fruits

  • 2 probiotics (low-fat yogurt)

  • 1-2 servings of friendly fats

  • Green tea

  • 64 ounces of water

Cycle 2 is the same as cycle one except it reduces the fat to one serving and adds two servings of healthy carbs, pushing the calories to about 1,500 daily, Nodvin says.

Healthy starches such as legumes, brown rice, bulgar, couscous, corn, squash, and sweet potatoes are just a few of the options to choose from.

During this phase, you alternate lower-calorie days with slightly higher-calorie days.

Cycle 3 allows for the addition of more healthy food choices to help you achieve good lifetime eating habits. Food lists are expanded to include more healthy fruits, proteins, fats, and starches. The meal plan is basically the same as Cycle Two, except protein is restricted to portions equal to the size of a sponge and an added option for one serving of alcohol and 100-calorie snacks.

Cycle 4 assumes you have met your goal weight. If you were lucky enough to lose all your weight in 51 days, this phase is about maintaining the new you. During the week, follow the guidance from cycle 1,2, or 3 and when the weekend rolls around, let loose.

Moreno allows 1-2 favorite meals, and 1-2 alcoholic drinks daily on the weekends, but cautions dieters not to binge; he calls it strategic cheating. "If you only splurge a little, it will keep your weight in check and make it easier to get back on track on Monday," Moreno says.

He suggests weighing in weekly and when the needle goes up five pounds, return to cycle 2 until you get your weight back to normal.


Weight loss occurs in the belly before anywhere else. See Answer

The 17 Day Diet: How It Works

Dieters clean up their diets, getting rid of fast foods, sweets, refined grains, and more in cycle one. This phase is designed to "improve digestive health, help clear sugar from blood to boost fat-burning and discourage fat storage," Moreno says.

Cycle 2 "causes calorie confusion, resets your metabolism by increasing and decreasing calorie intake to stimulate fat burning and prevent plateaus," Moreno writes in The 17 Day Diet.

Cycle 3 has a liberalized meal plan that reintroduces healthy foods in proper portions along with one alcoholic drink per day. Expect weight loss to slow down unless you forgo alcohol and/or increase aerobic exercise.

Assuming you achieve your weight loss goal by the end of cycle 3, you can progress to cycle 4 or maintenance. If not, return to cycle two and three until you arrive at your goal weight.

Strategic cheating is the bonus in the final phase, where you can enjoy your favorite foods, within reason, on weekends. Dieters are allowed up to three favorite meals during the weekends.

Throughout the plan, dieters are encouraged to use portion control, eat breakfast, lots of salads, make healthy substitutes (mustard instead of mayo, for example), get in touch with their hunger cues, drink at least 64 ounces of water daily, and eat slowly.

No fruit after 2 p.m. is a red-flag tip that Moreno explains is because "it is harder to burn off these calories and they might get stored as fat." Diet and nutrition experts say what matters is the total number of calories consumed, not the time of day or type of food.

The 17 Day Diet: What Dietitians Say

Experts give thumbs-up for the food choices, overall message of clean eating, avoiding unhealthy carbs, enjoying foods that you love, and regular exercise. But thumbs-down on the weight loss theory and restriction of healthy foods like fruits and low-fat dairy.

"If you can get beyond the gimmicky title and past the weight loss theories, which are very loosely based on science, it is a good plan resembling what most people try to do on their own," Nodvin says.

American Dietetic Association spokeswoman Keri Gans, MS, RD agrees. "There is no evidence that you can fool your metabolism by calorie-shifting but the low-calorie plans featuring healthy foods are a good approach to weight loss," she says.

Gans cautions that the weight loss is not because of metabolism confusion but primarily due to cutting calories, and that the initial water weight loss may be short-lived and not sustainable once you bring carbs back into your diet.

Anyone who exercises strenuously may require more snacks and calories, Gans says.

The 17 Day Diet: Food for Thought

Despite the plan's title, you will not lose weight quickly and keep it off after being on this plan for only 17 days.

Alternating between cycle 1 and cycle 2 might prevent boredom, but it really is just a strategy to cut calories and give you staying power to stick with the plan.

Although the evidence is lacking to substantiate Moreno's weight loss theory of metabolic adjustment to burn fat, the principles of the diet are the foundation of all good diet plans: Cut calories; eat healthy foods; limit sugars, alcohol, and refined starches; and get regular exercise. That's solid advice that will lead to successful weight control.

Eat fruit whenever you want and add a once-daily multivitamin mineral to fill in nutritional gaps and the 17 Day Diet could be your answer to long-term weight control.

Kathleen Zelman, MPH, RD, is director of nutrition for WebMD. Her opinions and conclusions are her own.


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Michael Moreno, MD, author, 17 Day Diet; family physician, Kaiser Permanente, San Diego.

Keri Gans, MS, RD, dietitian in private practice in New York; spokeswoman, American Dietetic Association.

Melissa Nodvin, MS, RD, chief wellness officer, Health-Ally.

Moreno, M. The 17 Day Diet: A Doctor's Plan Designed for Rapid Weight Loss Results, 2010.

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