When translated to English, the phrase "como bajar de peso rapido" means "how to lose weight fast." "Como bajar de peso rapido" is a Spanish phrase that can be translated to any other language.
The Spanish word "bajar" can translate to either "to go down" or "to decrease" in English but in this specific phrase, the word "lose" is chosen to make it a proper translation. It is also considered a proper translation to English from Spanish by saying "like growing thin rapidly." Any of the mentioned English phrases are all considered proper in both the English and Spanish languages.