[Steve]

If you were eating 150 calories per day at 400+ lbs.... and STILL not losing weight.... something is going on medically and you should see a doctor.

Although, I hate to tell you, it would be the first case of it's kind. Eating that few calories, even with medical pathologies, would still lead to weight loss.

It isn't acute caloric intakes that matter. What matters is longer continuums.

So, if you were eating 150 calories per day (I highly doubt this) M-F, and then on the weekends ate 10000 calories per day.... the numbers would net out.

This aside, at your weight, losing is quite easy. It doesn't take science or magic. It's simply a matter of controlling your portions and increasing activity on a consistent basis.

As much as you think you were only eating 150 calories per day, there is something called the Laws of Thermodynamics. With these in mind, it would be impossible for a 400+ lb man to MAINTAIN that weight without consuming a large quantity of food.