Disclosure: This page may contain affiliate links. If you buy through them, we may earn a commission at no extra cost to you. Product details below come from the vendor and have not been independently verified by RecipesForJuicing.net.
The 21-Day Smoothie Diet: An Honest Overview
The 21-Day Smoothie Diet is a digital meal-replacement program: you swap some daily meals for smoothies for three weeks. Here's what the vendor says you get, what research on meal-replacement plans actually shows, and who should talk to a doctor before trying it.
How the Program Works
According to the vendor, the plan replaces two meals a day (typically breakfast and lunch) with smoothies, with one regular meal in the evening, for 21 days. The recipes are designed to be made in a standard blender from whole fruits, vegetables and other grocery-store ingredients.
What the Vendor Says Is Included
The vendor's sales page lists the following. We have not independently verified the contents:
- A collection of smoothie recipes (the vendor states 36)
- A day-by-day 21-day smoothie schedule
- Weekly shopping lists
- An optional 3-day "detox" smoothie phase
- A guide to transitioning back to regular meals afterward
- Instant digital (PDF) access
The vendor also advertises a 60-day money-back guarantee. Guarantee terms and pricing are set by the vendor and can change, so check the current terms on the vendor's page before you buy.
A note on "detox": your liver and kidneys handle detoxification continuously. A few days of smoothies won't speed that up — see our evidence review of juice and liver health.
What the Research Says About Meal-Replacement Plans
Structured plans that replace one or two meals a day with a controlled-calorie drink have been studied for decades. A 2003 meta-analysis in the International Journal of Obesity (Heymsfield et al.) pooled six randomized trials and found that partial meal-replacement plans produced modestly greater weight loss than conventional reduced-calorie diets over periods of three months to a year.
Two important caveats:
- Those studies mostly used formulated meal-replacement shakes with set amounts of protein, vitamins and minerals — not homemade fruit smoothies, which can vary widely in calories and are often low in protein.
- Weight lost on any short program tends to return unless eating habits change for the long term. Individual results vary.
If you try any smoothie-based plan, include a protein source (Greek yogurt, milk or soy milk, nut butter, or protein powder) and vegetables, and watch portion sizes of fruit, juice and sweeteners.
Who Should Check With a Doctor First
- People with diabetes, especially if you take insulin or other glucose-lowering medication
- Anyone who is pregnant or breastfeeding
- People with kidney disease (many smoothie ingredients are high in potassium)
- Anyone with a current or past eating disorder
- Children and teenagers
Prefer Juicing? Related Guides
Get the Program
If you've decided it suits you, the program is available as a digital download.
The program is sold as a digital download through the vendor's official website.
Frequently Asked Questions
Is a smoothie diet the same as juicing?
No. Blending keeps the whole fruit or vegetable, including its fiber; juicing removes most of the insoluble fiber. Smoothies tend to be more filling as a meal replacement, while juice is usually drunk alongside meals. Our juicing vs. blending guide covers the differences.
Do I need a special blender?
For most smoothie recipes, any standard countertop blender works. High-powered blenders make smoother results with frozen fruit, leafy greens and seeds, but they are not essential.
How much does following a smoothie plan cost per day?
It depends on your ingredients and local prices. Frozen fruit, bananas, oats and spinach keep costs down; fresh berries and protein powder push them up. Our Price Calculator can help you estimate your own cost.
Will replacing meals with smoothies help me lose weight?
Replacing meals with lower-calorie drinks can reduce total calorie intake, and structured meal-replacement plans have produced modest weight loss in studies (see the research section above). Results vary widely between people, and smoothies made mostly of fruit can be low in protein. Your overall diet over time matters more than any 21-day program.
This page is for general information only and is not medical advice.