new to /fit/ so hi!
my boyfriend has been drinking a LOT of milk in attempt to gain weight. multiple gallons per week. slightly concerned for his health. he's 135lbs and 5'11 and works out consistently around 2-5 times a week.

im not entirely sure how many calories he consumes daily, but id assume hefty amount is primarily from milk. will this work? will it negatively impact his health?