The practice of drinking only water for a day without eating is often called "water fasting." Although it may cause weight loss in the short term, this method is not healthy and is not recommended for long-term use. Water fasting may cause nutrient deficiencies, insufficient energy, slowed metabolism, and other health problems. For most people, if you consider a short-term fast, it is recommended not to exceed 24 to 48 hours. Beyond this time, the body may begin to react negatively, including muscle loss, weakened immune system, etc. In order to lose weight healthily, it is more recommended to combine a balanced diet with regular exercise. Include enough fruits, vegetables, protein and healthy fats, while maintaining a good water intake. Moreover, it is best to carry out a weight loss plan under the guidance of a professional to ensure good health. If you have weight loss or dietary needs, it is recommended to consult a nutritionist or doctor for advice.