Its possible, people lose weight at different rates
http://www.exrx.net/Notes/WeightLossAbstracts.html
Somewhere on there is an article about 14 or so sets of identical twin sisters going on a 400 calorie a day diet for 28 days. One person only lost about 2.4 lbs of fat a week, but another twin lost almost 7 lbs of fat a week. The twin who lost 7 lbs of fat a week also lost no muscle.
Since your male i would assume its possible that on a 400 calorie a day diet you would lose around 4 lbs of fat a week, if you are genetically gifted maybe 5 or 6. But you’ll lose alot of muscle too, i dont know if that matters.
Aside from that, you can use semi-illegal drugs. But i doubt you’d want to.