If the only way you can eat calories at a surplus is by drinking a gallon of milk a day then you should contemplate getting a g-tube.
GOMAD is a bad idea. Milk is extremely insulinogenic not to mention our bodies have limited ability to break down lactose.
Not to mention 1 gallon of milk has 208g of sugar which is 832 calories.
Spare yourself the diarrhea and diabetes and just eat a normal diet. Milk has its place but advocating to haphazardly add 2336 calories to your diet is beyond absurd. Just because something worked for a few individuals doesn't mean is a good idea. Search "__ (insert random word from dictionary) diet works" and you will find tons of success stories!
Edit: Some math to show why the average trainee doesn't need 5000 calories
Lets take Jim. A skinny guy who wants to be buff! Perfect candidate for GOMAD!
- Height: 5'10
- Weight: 140lbs
- Age: 21
- BMR: ~1700
Jim, as most people are, is pretty sedentary but lets assume he's pretty active and give him a ~1.5 calorie multiplier. Which means he needs 2550 calories to maintain his weight. But Jim wants to GO-MAD! So he adds a ~2450 daily calorie surplus to his diet because hell he wants to get results quick.
So lets assume to add 1lb of muscle you need 2500 calories. Lets also assume you can gain 1lb of muscle per week. Both 'estimates' are extremely optimistic. So in order to gain 1lb of muscle per week Jim has to eat a weekly surplus of 2500 calories, which translates into 357 calories per day or ~2900 calories.
Instead Jim is doing 5000, which means he's eating an extra 2000 calories on top of what he needs to gain 1lb of muscle a week! Or an extra ~14000 calories per week. Which translates into a nice 4lbs of fat per week.
Comparing this against the hypothesis "GOMAD, gain 25lbs in 25 days", Jim falls short by only gaining 17.5lbs in 25 days. Lets add some bloating, water retention and increased glycogen levels due to the absurd surplus and sugar and you can easily see how its possible.
At the end of the experiment Jim gained:
- 3.5 lbs of muscle
- 14 lbs of fat
- 7.5 lbs in bloating, water retention and increased glycogen storage
Will GOMAD increase your strength? Yes. Will drinking 3 liters of soda also increase your strength? Yes. Should you do either? No.