Eating sweet potatoes in moderation at night will not make you fat, and eating sweet potatoes in excess will make you fat. As a root food, sweet potato can be used as one of the staple food, replacing part of the traditional staple food such as refined rice and refined noodles. One hundred grams of sweet potato calories for 86 calories, carbohydrates 20.12 grams, 0.1 grams of fat, protein 1.57 grams, fiber 3 grams. Therefore, sweet potato’s calories mainly come from carbohydrates, protein, and less fat, which is one of the reasons it is used as a staple food. At the same time, its fiber content is much higher than rice and noodles, which helps intestinal peristalsis and increases satiety. Because of the sweet potato’s sweet flavor, if it is consumed freely without controlling the amount, instead, the calorie intake is greater than that of eating rice and noodles. So when eating sweet potatoes at night for weight loss, you must pay attention to control the intake of sweet potatoes to achieve the purpose of weight loss. Weight loss can not rely solely on sweet potatoes, but also need to combine other foods, to achieve a comprehensive and balanced nutrition, moderate exercise, to ensure the sustainability of weight loss.