The key, according to the San Diego family medicine doctor, lies in changing your calorie count and food combinations every 17 days for four cycles. This, he says, keeps your metabolism in a fat-burning state because it is constantly guessing how much food it will have to process.
What You Can Eat and What You Can't
The plan relies on lean protein, antioxidant-rich produce, probiotics, and good fats. It bans sugar, processed foods, salty foods, and fried foods.
Early on, you minimize starchy vegetables and high-sugar fruits, and cheats like alcohol are off the table entirely.
As the diet progresses, though, it gradually eases up. By the end, you can have the occasional drink, 100-calorie snack, or cheat meal.
Because of how our metabolism changes throughout the day, you should only eat fruit before 2 p.m., Moreno says.
Level of Effort: Medium
Even at its strictest, the plan gives you plenty of variety and personal choice.
Limitations: The diet starts off at its most restrictive -- 1,200 calories, with a high-protein, low-fat, no-carb emphasis (including minimizing starchy vegetables and fruits). But as users move through the cycles, more and more foods are added.
Package foods or meals: Optional. Diet delivery service BistroMD offers customizable menus for under $185 per week at www.17daydietdelivery.com.
In-person meetings: No.
Does It Allow for Dietary Restrictions or Preferences?
Vegetarians and vegans: Though the core diet is anchored in plenty of animal products -- lean meat, fish, eggs, and probiotic-rich dairy products are emphasized -- there are plenty of substitutions that can be made, among them tofu, rice protein powder, and soy milk.
Low-salt diet: The diet recommends low-salt foods.
What Else You Should Know
Cost: None beyond your groceries.
Support: There’s a 17 Day Diet app, which includes recipes and a tool to check whether a food is allowed. A number of online support communities also exist including a 17 Day Diet Facebook page.
What Dr. Melinda Ratini Says:
Does It Work?
Experts are mixed on metabolism-revving claims such as Moreno’s. And research on the use of probiotics as a weight loss aid or general wellness booster is lacking. Though probiotics are at the core of the 17 Day diet plan, most of the research on probiotics has dealt with their use in the prevention or treatment of gastrointestinal disease and allergies.
But what’s certain is that the diet is anchored in whole foods, regular exercise, and other good habits that can help achieve lasting weight loss and weight maintenance.
Is It Good for Certain Conditions?
Weight loss and exercise are proven ways to help prevent and treat heart disease and diabetes. They also help keep blood pressure under control and help raise good HDL cholesterol and lower bad LDL cholesterol. Throw in the plan’s emphasis on low-fat and low-salt foods, and you can lower your risk even more.
If you have kidney disease, this plan might include too much protein for you. Check with your dietitian or doctor about your particular protein needs.
The exercise portion of the program starts slowly with just 17 minutes a day of a moderate activity like walking. It quickly increases to 40 to 60 minutes of aerobic activity on most days. If you have heart disease or any other medical conditions, you should check with your doctor before starting this program.
The Final Word
Whether it revs up your metabolism or not, the 17 Day Diet provides a framework of diet and exercise that may help you shed the pounds. Even at its most restrictive phase, the plan allows enough calories to provide an interesting and balanced diet. And it lets you add activity gradually until you meet or exceed the amount recommended by the American Heart Association and most health experts. The maintenance phase and strong support communities should help to reinforce long-term success.
If you eat out a lot, are on the road, or have a very busy schedule, it may be challenging to find the time needed to shop for and prepare these meals. You will need to be highly motivated. Also, you will be spending money on probiotics that may not really be helping you meet your nutrition and fitness goals.
Check with your doctor before starting the 17 Day Diet if you have heart or kidney disease or any other medical problems to be sure it is right for you.