You've probably seen the headlines or the glossy Instagram posts of celebrities looking impossibly lean and energized after a "quick reset." Usually, that's Harley Pasternak’s doing. He's the guy behind the body reset diet, and honestly, it’s one of those plans that people love to hate until they actually look at the mechanics of how it works. It isn't just about starving yourself on green juice for a week. That’s a common misconception.
It's fast. 15 days, to be exact.
Most people jump into this thinking they’ll just blend some spinach and call it a day. That's a mistake. The actual protocol is a very specific, three-phase journey designed to kickstart your metabolism by manipulating how your body processes liquid versus solid nutrients. It’s intense. If you aren't prepared for the sheer volume of fiber you’re about to consume, your digestive system is going to have a very loud conversation with you by day three.
Breaking Down the Phases of the Body Reset Diet
The first five days are the "Power Smoothie" phase. You aren't eating solid food. Instead, you're drinking three smoothies a day—white for breakfast, red for lunch, and green for dinner. Pasternak designed these to be macro-complete. The white smoothie is usually Greek yogurt or milk-based for protein; the red is fruit-based for antioxidants; and the green is veggie-heavy for fiber.
You also get two crunchy snacks. Think apples, celery, or a handful of almonds.
Phase two is where things get a bit more "normal." From day 6 to 10, you keep two smoothies but swap one out for a solid meal. This is usually a "S.S.S." meal—soup, salad, or stir-fry. The logic here is simple: high volume, low calorie. You're training your brain to feel full on foods that don't have a massive caloric density. It's about retraining the satiety response.
By the time you hit phase three (days 11-15), you’re down to one smoothie and two solid meals.
Why the Smoothie Color Matters
It isn't just for the aesthetic. Each color represents a specific nutritional goal. The body reset diet relies on these colors to ensure you aren't missing key micronutrients while you're in a significant calorie deficit.
- White Smoothies: These are your protein anchors. Usually featuring ingredients like ginger, banana, and Greek yogurt, they focus on gut health and muscle preservation.
- Red Smoothies: Think berries. Raspberries, blueberries, strawberries. These are packed with anthocyanins. They taste the best, honestly.
- Green Smoothies: The workhorses. Spinach, kale, grapes, and pear. This is where you get the bulk of your fiber.
The Science of Chewing and Satiety
One of the biggest criticisms of liquid diets is that they don't keep you full. Pasternak argues against this by focusing on fiber and protein, but there is a psychological component he talks about regarding the "crunch factor."
Humans like to chew.
That’s why the snacks are mandatory. If you just drink your calories, your brain often fails to register that you’ve actually "eaten." This leads to the dreaded "hangry" spiral. By keeping those two snacks—like edamame or a pear—the body reset diet tries to trick your brain into feeling like it’s still participating in a traditional eating pattern.
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Is it perfect? No.
Medical experts often point out that rapid weight loss in a 15-day window is mostly water weight and glycogen depletion. Dr. Melina Jampolis, a physician nutrition specialist, has noted in various interviews that while these plans can provide a "psychological win," they don't necessarily teach long-term habits unless you stick to the philosophy after the 15 days are up. You can't just go back to pizza and beer on day 16 and expect the results to stay.
Exercise: Less is Actually More Here
This is where the plan departs from traditional "hardcore" fitness regimes. Pasternak actually discourages heavy weightlifting or intense HIIT cardio during these 15 days.
Why? Because you're on a low-calorie budget.
If you try to hit a personal best on your deadlift while only consuming 1,200 calories of smoothies, you're going to crash. Hard. Instead, the body reset diet mandates a minimum of 10,000 steps a day. It’s about "Non-Exercise Activity Thermogenesis" (NEAT). Basically, just move your body consistently without overstressing your central nervous system.
He also suggests five minutes of resistance exercise every other day. Just five. It’s almost laughable compared to most gym programs, but the goal is maintenance, not muscle building, during this specific window.
Common Pitfalls and Reality Checks
Let's be real: the first three days suck.
You will likely have a headache. This is usually from caffeine withdrawal (if you’re cutting that out too) or simply the sudden drop in processed sugar. The body reset diet is a massive shock to the system if your current diet involves a lot of "beige" foods.
Another issue? The blender. You are going to be cleaning your blender constantly. If you don't have a high-powered one (like a Vitamix or Ninja), your green smoothies will be "chewy" in a way that is profoundly unpleasant. Nobody wants to drink a chunk of kale.
The Protein Problem
If you’re an athlete or someone with a lot of muscle mass, the protein levels in the standard reset might feel a bit low. Many people find they need to add a scoop of unsweetened protein powder to the smoothies to keep from feeling lethargic.
What the Research Says
There isn't a specific, peer-reviewed clinical trial specifically titled "The Body Reset Diet 15-Day Study." However, the components are backed by broader nutritional science.
A study published in the American Journal of Clinical Nutrition has shown that high-protein, high-fiber diets are significantly more effective for short-term satiety than high-carb, low-fat diets. Furthermore, the concept of "volumetrics"—eating large amounts of low-calorie food—is a well-documented strategy for weight management.
But there’s a catch.
The British Dietetic Association (BDA) and other health organizations often warn against "rapid reset" diets because they can foster a boom-and-bust relationship with food. The risk of weight regain is high. To make this work, you have to view the 15 days as a "palate cleanser," not a finish line.
Actionable Steps for a Successful Reset
If you’re going to try this, don't just wing it. Preparation is the only way you don't end up at a drive-thru by Wednesday.
- Prep your liquids. Buy your frozen berries and bags of spinach in bulk. Frozen is actually better here because it gives the smoothies a thicker, milkshake-like consistency.
- Invest in a portable container. You’ll be taking these smoothies to work. If they sit and separate, they become gross. Get a shaker bottle with a wire ball to remix them.
- Audit your snacks. Don't "eyeball" a handful of almonds. That's how 100 calories becomes 400 calories. Use a scale or count them out (usually about 10-12 almonds).
- Hydrate beyond the smoothies. You still need water. A lot of it. The fiber increase requires extra water to move through your system, or you'll end up bloated and miserable.
- Plan your "Day 16". This is the most important step. Have a plan for how you’ll eat once the 15 days are over. Transition into a Mediterranean-style diet or something sustainable so you don't rebound.
The body reset diet is a tool. Like any tool, it depends on the person holding it. It’s a sprint designed to give you the motivation to start a marathon. Just make sure you're ready for the pace.