<unk> s are popular non-standard diets that often promise dramatic weight loss. However, they are usually not supported by scientific evidence, and they sometimes offer dangerous dietary advice. A<unk>  is a diet that becomes popular for a short time, similar to<unk> s in fashion, without being a standard dietary recommendation, and often making unreasonable claims for fast weight loss or health improvements. There is no single definition of what is a<unk> . The term<unk>  encompasses a variety of diets with different approaches and evidence bases, and thus different outcomes, advantages, and disadvantages. Generally,<unk> s promise an assortment of short-term changes requiring little to no effort; attracting the interests of uneducated consumers about whole-diet, whole-lifestyle changes necessary for sustainable health benefices.<unk> s are often promoted with exaggerated claims, such as rapid weight loss of more than 1 kg/week or improving health by "detoxification", or even dangerous claims, such as highly restrictive and nutritionally unbalanced food choices leading to malnutrition or eating non-food items like cotton wool. Highly restrictive<unk> s should be avoided. At best,<unk> s may offer novel and engaging ways to reduce caloric intake, but at worst they may be medically unsuitable to the individual, unsustainable, or even dangerous. Dietitian advice should be preferred before attempting any diet. Celebrity endorsements are frequently used to promote<unk> s, which may generate significant revenue for the creators of the diets through the sale of associated products. Regardless of their evidence base, or lack thereof,<unk> s are extremely popular, with over 1500 books published each year, and many consumers willing to pay into an industry worth $35 billion per year in the United States. About 14-15% Americans declare having used a<unk>  for short-term weight loss. Although<unk> s may have a negative connotation for health professionals, some have scientific evidences and therapeutic applications, such as the ketogenic diet for epilepsy or caloric restriction and the Mediterranean diet for obesity and diabetes, and several producing similar benefits to commercial diets or standard care when done under professional supervision.
Fad diet
Plant-based diet
Rice diet
Atkins diet
Feingold diet
Western pattern diet
BRAT diet
Low-FODMAP diet