The basal metabolic rate for a 30 yr old male weighing 250lbs, varying from 5'10" to 7' tall is only 2,000 to 2,300 calories. Use anti catabolic drugs and only do it for a few weeks it's believable. Plus even stuff like bcaas and L glutamine, it can help preserve mass. When you're bloated with water, your real lean mass is lower than you think too.