The Smoothie Diet is a weight loss program that revolves around consuming smoothies as the primary source of nutrition for 21 days. The program provides participants with a variety of smoothie recipes, each designed to be nutritionally balanced and calorie-controlled. The goal is to replace traditional meals and snacks with these carefully crafted smoothies, leading to a calorie deficit and ultimately, rapid weight loss. These smoothies are intended to be packed with nutrients and low in calories, which can help create a calorie deficit and support weight loss. The program also encourages the consumption of whole foods for the remaining meals and snacks throughout the day.