Okay - say workout is at 500pm. You ate at 200pm. You train and are drinking Glutamine w/ BCAA's during workout. You finish at 630pm, you drink PW shake (that you packed and brought with you). You eat before bed at 930-1000pm... The longest span of non-eating is usally prior to the gym. Just try to eat ~ 3-4hrs before you know you will have your PW shake. Its all time management with these meals.
I never took in gatorade during workout and neither did most anyone I worked out around or trained with. Just drank water, took a lot of Liver and Mass pills or drank Glutamine with branch chains...keeps you going until the PW shake.
You said "LEAN" mass. To have a higher ratio of lean mass, you have a lower ratio of body fat - therefore I assume you are trying to achieve that. This is why I suggest the space in the meals, the water...the removal of this sugar laden drink. You can achieve your lean mass more easily this way. I didn't mean to bungle up the works.