Many people have heard that guava tea aids weight loss, but so far, there is no conclusive scientific evidence to support the idea. It's true guava fruit itself can help maintain a healthy weight because it is low in calories and high in beneficial fiber. However, benefits from fiber don't pertain to guava tea. One way guava tea can assist weight loss is to replace high-calorie beverages like coffee with cream or sugary sodas with unsweetened guava leaf tea.