What is the Glycemic Index of coffee with milk and sugar?

[taurusphere]

I've noticed that, regardless of calorie intake, I loose weight more easily if I avoid my usual 3-4 cups of coffee that each contain an 1/4 cup whole milk plus 4-6 teaspoons of white sugar. My mother has always drank coffee with lots of creme and sugar and was overweight my whole life- I've never seen her slim, but she was tall and thin before 30. She has also suspected the coffee with creme and sugar, not for staying fat but for initially getting fat.