It took me forever to drop pop. I was diagnosed as a diabetic, and told of all the dangers, but I drank a 2-liter of Pepsi for years afterwards.
I found that if I ate sugary foods, then I would drink sugary drinks. In the end I cut out most sugars, including pop.. cold turkey on the pop, after reducing the sugars. You may want to start by cutting the sugary sauces, like dressing, and ketchup, then sweets. Finally maybe switch him over to sweet tea, and reduce sugar as time goes on. Eventually he will just need to wean himself off the pop.
Another thing is how much he is drinking? I noticed that my drinking of sugared beverages doubled in my mid 20's, and a few years after that was diagnosed diabetic. I craved sugar, and was also thirsty, so it just kept building. It may be a good idea to get tested, and hopefully he can cut out this bad habit, or reduce it enough so he can avoid it, if he doesn't have it already.
Russell - current BMI 31.4
197 - bmi-30
164 - bmi-25
| current weight: 193.6