Oooh, my. While you don't really have to watch your calories and such on Atkins, I think you shouldn't gorge either. Given the sizes you are saying, that sounds like it might be a very high number for calories. Not sure if that would put fat on if you are in ketosis, but it would supply more than enough energy in his food such that his body wouldn't try to burn any of his fat.

Have you tried http://www.fitday.com

You could put the food in for him, and see where the numbers come out. Shoot for a ratio of 65% of calories from fat, 30% from protein and 5% from carbs. Calories for a day are generally recommended to be 10-12 times your goal weight. I for instance shoot for about 1800-2500 calories. You may not want to be that picky, but I did find it helped me. I had kept on eating the way I used to at the start and was eating a lot of calories and protein and not getting anywhere.

Just a suggestion, use as you wish