High-sugar foods are considered unhealthy because they contain large amounts of added sugars, which provide empty calories and can contribute to weight gain, tooth decay, and other health problems if consumed in excess. High-sugar foods can also cause spikes in blood sugar levels, which can lead to energy crashes, cravings, and other negative health effects. High-sugar foods include pastries, candy, sweetened breakfast cereals, and sugary drinks. Consuming high-sugar foods regularly can also increase the risk of chronic diseases such as type 2 diabetes, obesity, and heart disease. It is recommended to limit the intake of high-sugar foods and choose foods that are naturally low in sugar, such as fresh fruits and vegetables, to maintain a healthy diet.