I'm taking the Optimum Nutrition Serious Mass. You have to take 334G (two huge scoops) for a full serving which contains 1250 calories and 50g of protein. I'm having trouble drinking this stuff on a daily basis. I get a really full uncomfortable feeling after drinking just a half serving. You guys have any tips on how to take this stuff? I'm only on my 2nd day so does it get better the more you take it? This is basically my only option to gain weight. My schedule is so busy that I don't have time to prepare the amount of meals to get 3500-4000 calories.