Created by Dr. Mike Moreno in 2010, The 17 Day Diet is a structured weight-loss program designed to yield rapid initial results and transition into a long-term, sustainable lifestyle. The diet relies on a concept Dr. Moreno calls “metabolic confusion”—frequently changing your calorie intake and food combinations every 17 days to keep your metabolism guessing and prevent frustrating weight-loss plateaus.
Here is a complete breakdown of how the diet works and the rules for each phase.
The Four Cycles of the Diet
The program is broken down into four distinct phases. The first three phases last exactly 17 days each. As you progress through the cycles, the diet gradually becomes less restrictive and easier to manage.
Cycle 1: Accelerate (Days 1–17)
- Goal: Rapid weight loss (up to 10–12 pounds), detoxification, and flushing excess sugar from your system.
- Dietary Rules: This is the most restrictive phase, hovering around 1,200 calories per day. You can eat unlimited amounts of lean proteins (chicken breast, turkey, fish, eggs) and non-starchy vegetables (broccoli, leafy greens, asparagus, bell peppers).
- Restrictions: No starchy carbohydrates, potatoes, alcohol, or refined sugars.
- Additions: You are allowed two servings of low-sugar fruit (like berries or apples) and two servings of probiotic-rich foods (like plain yogurt or kefir) daily.
Cycle 2: Activate (Days 18–34)
- Goal: Reset your metabolism to prevent it from slowing down.
- Dietary Rules: This phase uses alternate-day fasting. You alternate between low-calorie days (simply repeating the Cycle 1 menu) and higher-calorie days.
- Additions: On the higher-calorie days, you are allowed to add two daily servings of natural, starchy carbohydrates, such as sweet potatoes, legumes, or brown rice.
Cycle 3: Achieve (Days 35–51)
- Goal: Establish steady, sustainable weight loss and learn portion control.
- Dietary Rules: The strict alternate-day fasting ends, and you eat a more balanced diet every day.
- Additions: You can now introduce whole-wheat breads, high-fiber cereals, whole-grain pastas, and a wider variety of fruits. You are also allowed one alcoholic beverage per day and moderate, healthy snacks.
Cycle 4: Arrive (Days 52 and Beyond)
- Goal: Long-term weight maintenance for the rest of your life.
- Dietary Rules: From Monday morning to Friday lunch, you strictly follow the healthy meal plans from Cycles 1, 2, or 3.
- The Weekend Reward: From Friday dinner through Sunday dinner, you are allowed one to two “cheat” meals to enjoy your favorite indulgences (pizza, burgers, desserts, etc.) and up to two alcoholic beverages.
Key Rules Across All Cycles
Regardless of which phase you are currently in, the 17 Day Diet requires strict adherence to a few foundational habits:
- No Carbs After 2:00 PM: Dr. Moreno argues that carbohydrates eaten later in the afternoon or evening are less likely to be burned off for energy and more likely to be stored as fat.
- Prioritize Probiotics: Eating two servings of probiotic foods (like yogurt, kimchi, or sauerkraut) daily is mandatory to optimize digestion, reduce bloating, and promote a healthy gut microbiome.
- Stay Hydrated: You must drink eight 8-ounce glasses of pure water every day. Green tea is also highly encouraged with meals to lightly boost metabolism.
- Daily Exercise: The diet requires 17 minutes of light exercise (like brisk walking) daily during Cycles 1 and 2, which increases to 40–60 minutes of aerobic exercise in Cycles 3 and 4.
Pros and Cons of the 17 Day Diet
| Pros | Cons |
| Fast Initial Results: Rapid weight loss in Cycle 1 provides a massive psychological motivation boost. | Water Weight: Much of the initial weight lost in the first cycle is water weight rather than pure body fat. |
| Promotes Whole Foods: Eliminates processed junk food and heavily limits refined sugars. | Arbitrary Rules: The “no carbs after 2:00 PM” rule lacks strong scientific consensus; total daily calories matter more. |
| Gut Health Focus: The emphasis on daily probiotics naturally optimizes digestion and overall health. | Early Fatigue: The strict 1,200-calorie limit in Cycle 1 can leave you feeling tired, hungry, or irritable. |
| Realistic Maintenance: Cycle 4 allows for guilt-free weekend indulgences, preventing long-term burnout. | High Prep Time: Requires frequent grocery shopping and home cooking with fresh, whole ingredients. |