Stevia Sweet Leaf Tea, known to tea aficionados as naturally sweet tea, this one is 35 to 45 times as strong as refined sugar and it has the benefit of being absolutely calorie-free. This makes stevia a great choice for diabetics and tea lovers who wish to control their intake of sugar. You will want to use just a little of the tea when brewing as too much of it will impart a slight bitterness and anise like taste to the brew.