The 21-Day Smoothie Diet is a weight loss plan touted as an easy and effective alternative to fad diets.
In fact, the creator of the plan claims that the diet is associated with a long list of benefits and can help improve sleep, keep your skin glowing, skyrocket energy levels, and increase weight loss almost instantly.
However, there are several serious downsides associated with this program, and it may do more harm than good in the long run when it comes to your health.
This article will take a closer look at the 21-Day Smoothie Diet, how it works, and some of the negative risks and side effects it may be associated with.
The plan involves swapping two of your meals each day with smoothies, and the principles of the program are outlined in the e-book, “The Smoothie Diet,” which is available online for $47.
The e-book includes 36 smoothie recipes, meal and snack ideas, shopping lists, weekly schedules, and tips for preparing the smoothies and maintaining weight loss long-term.
According to Sgoutas, the 3-week diet plan can help promote healthy eating, enhance immune function, detoxify the body, improve skin and gut health, and rev up energy levels.
Sgoutas also claims that the diet can boost weight loss. In fact, some testimonials displayed on the website claim that the plan led to up to 9 pounds (4 kg) of weight loss in just 3 days.
The 21-Day Smoothie Diet involves replacing two of your meals each day with smoothies using the recipes found in the e-book.
There are 36 recipes provided in the book, created using ingredients like fruits, vegetables, nuts, seeds, and almond or coconut milk.
In addition to these two smoothies, the plan allows you to eat one solid meal per day and two healthy snacks.
Solid meals should consist mostly of whole foods, and snacks should be low in sugar and high in fiber, with around 150–200 calories per serving.
You are also allowed one cheat day per week where you don’t consume any smoothies, though meals should still consist mostly of whole, minimally processed foods.
Optionally, you can kick off the plan with a 3-day detox, which requires you to consume a smoothie in place of all three daily meals, with two healthy snacks in between.
According to the program’s website, the diet works by creating a calorie deficit, meaning that you are expending more calories than you consume each day.
The diet is also high in fiber and claims to help reset your taste buds to reduce sugar cravings.
The program is intended to be followed for 3 weeks but can be repeated as many times as needed until you ‘reach your goal weight.’
Most of the smoothie recipes included in the 3-week program consist of fruits, vegetables, nuts, and seeds, mixed with coconut milk, coconut water, or almond milk.
Additionally, the plan emphasizes whole, minimally processed foods for your remaining meals and snacks while following the diet.
On the 21-Day Smoothie Diet, you should limit your intake of sugar-sweetened beverages and processed foods, including processed meat, refined grains, and fried foods.
According to the 21-Day Smoothie Diet creator, the plan provides a total of around 1,500 calories per day.
Consuming 1,500 calories per day will lead to weight loss for many people. However, this may vary based on many different factors, including your age, body size, health status, and activity level (1).
The diet also encourages a variety of nutrient-dense foods, like fruits, vegetables, nuts, and seeds, all of which are high in fiber.
Fiber moves through the digestive tract slowly, helping to keep you feeling fuller for longer, which could support weight loss (2, 3).
However, despite being low in calories and high in fiber, the 21-Day Smoothie is also very restrictive and can be difficult to follow.
Furthermore, research suggests that liquids, such as smoothies, are less filling than solid foods, meaning you may feel more hungry drinking mostly smoothies each day (4).
Not only that, but some studies show that weight loss programs that use meal replacements may be associated with a higher risk of weight regain once a typical diet is resumed (5, 6).
Therefore, while swapping some of your meals for smoothies may lead to short-term weight loss, it’s unlikely to be effective long-term.
In addition to being restrictive, unsustainable, and difficult to follow, the 21-Day Smoothie Diet may have several other downsides and side effects.
Include one or more sources of protein like yogurt, kefir or milk, as well as healthy fats from nuts, seeds or avocado. Both adults and children should consume smoothies no more than one portion per day.
May be high in sugar
Many of the smoothies on the 21-Day Smoothie Diet contain multiple servings of fruits, including bananas, pineapples, peaches, and strawberries.
Some also contain other high sugar ingredients, such as honey or granola.
Though these ingredients can be enjoyed as part of a healthy, balanced diet, the high amounts included in this diet may not be suitable for everyone.
In particular, people with diabetes may need to monitor their intake of foods high in carbohydrates, such as fruit or honey, to prevent spikes in blood sugar levels (10).
Increases risk of nutrient deficiencies
Eating just one solid meal per day and replacing your remaining two meals with smoothies may increase the risk of nutritional deficiencies.
Though the smoothie recipes recommended by this program contain nutrient-dense ingredients like fruits and veggies, they also omit or limit many of the foods typically included in a balanced meal, such as whole grains, healthy fats, and lean proteins.
Some are also low in protein. For example, the Green Detox smoothie — made with kale, coconut water, bananas, ginger, and lemon — contains less than 4 grams of protein per serving.
That makes it challenging to ensure you’re meeting your protein needs, negatively impacting tissue repair, muscle growth, immune function, and more (7).
Additionally, though the diet claims to provide around 1,500 calories per day, most the smoothie recipes are very low in calories and unlikely to provide enough calories to meet the needs of most healthy adults.
Consuming too few calories each day can slow your metabolism and cause serious negative side effects, including hunger, nausea, headaches, and fatigue (8, 9).
Can I drink 2 smoothies a day to lose weight?
FAQ
How many smoothies should you drink a day on a smoothie diet?
Is it OK to drink a lot of smoothies?
Is 2 cups of fruit too much for a smoothie?
Does drinking a smoothie count as eating?
How many smoothies can I eat a day?
Whilst you are allowed 2 smoothies and one meal a day. Even if you are receiving your smoothies pre-made for you it’s important to ensure that your one meal a day is balanced. These meals should contain the right amount of proteins, carbs, and fats as well as additional fruits and vegetables.
Are smoothies good for weight loss?
Smoothies may be effective for weight loss as long as they are not causing you to exceed your daily calorie needs. While some people find smoothies an easy way to monitor food portions and stay on top of their weight loss goals, others may not feel as full when they drink their calories rather than eating them. Smoothies are used as meal replacements and it can be filling as solid foods and that drinking calories instead of chewing them does not lead to overeating when solid foods are consumed later. If a smoothie helps you offset other calories you would otherwise consume, it can be an effective weight loss tool. If you prioritize ingredients low in calories and high in protein and fiber, your smoothie may keep you full and aids in weight loss.
Should you drink a smoothie every day?
“Drinking smoothies every day can have positive health benefits, like increasing your intake of fruits and vegetables, fiber, and antioxidants,” says Lisa Young, PhD, RDN. So, if you’re incorporating a variety of vegetables, fruit, seeds, nuts, and other nutritious ingredients, your smoothie can become one of the healthiest parts of your day.
When should you eat a smoothie?
This isn’t to say that a smoothie is only suitable as a first-thing-in-the-morning experience; as long as you’re hungry and have access to a blender, you can enjoy this fresh and frosty beverage any time you choose. The question is should you?