I'm sure many women switch to diet drinks to try to lose weight/stay slim when they are young. I know I did. I had been drinking diet drinks for about 30 years , (at a rate of 2 litres a day for several of those years) before I became T2. Worried about my weight gain I read a book about Syndrome X (metabolic syndrome) which said that the weight gain was due to insulin resistance which could be caused by consuming diet drinks. I don't think a small amount of these drinks is a problem but I don't think it's a good idea to drink an excess of them, they are made up of water and chemicals after all, so why not just have the water. You get used to it after a while.