No, not at all...!A cup of tea/coffee a day is not going to make any major difference to your weight. What actually makes the scale go up is what you eat along with it. As long as you choose healthy snacking options to go with tea/ coffee like roasted makhanas/homemade chivda etc.you are good to go. But if you choose items that are high in sodium, refined sugars, oil like chips, mathi, Namkeen etc. then GOD BLESS YOU. Also portion size matters again. There's a lot of difference between a MUG and a CUP. As long as you are sticking to a cup that's absolutely OK, but if you find yourself indulging into a mug of tea/ coffee loaded with sugar then that is unnecessarily adding a lot of calories. As long as you indulge keeping in mind these 2 things, you can include a cup of tea/ coffee while trying to lose weight..!