My son's weight loss efforts

My 11 year old son has been trying to lose 10 lbs to be able to play grid-kids football and has had no luck.  He is 5'1 and weighs 165.  We have cut his daily calories to about 1400 -  1500 and he's been walking 1 1/2 to 2 miles daily on our treadmill at a speed of 3.0 and an incline of 3.0.  He is drenched with sweat when done.  I have him drinking about 64-80 ozs. of water daily.  He has switched to whole grain breads only and sugar has been cut out (although sweets were never an issue), he is eating 4-6 small meals daily with his last meal consumed no later than 6:30 and our last exercise session at about 8:00 p.m.  Yet in two weeks he hasn't lost one pound.  We cannot figure out why and he is getting very discouraged.  Why could this be?  I want to offer him some encouragement and I keep telling him that his body will eventually let the weight go.  But with only 10 more days til weigh-in, I feel he won't be able to accomplish this.  Unfortunately that will only bring more discouragement.  I personally have not put in nearly as much effort as him and have managed to drop 5 lbs. myself in the past two week.  Please help.  He needs to lose weight but without any kind of encouragement on the scale, I fear he will lose momentum.  Thank you.

[sweetpea03]

I would take him to the doctors for a physical. He could have problems with his thyroid which won't allow him to lose weight or another issue. Talk to his doctor about it and see what options he has. The routine you have going now sounds really good, so not sure what is going on. It could be that it just takes his body a lot longer or it could be something else. It's just better to have him checked out. Good luck.