in a week's amount of time, you would actually lose less or even gain weight if you stopped eating in a short amount of time.

the little food you ate would be put into use immediatley and your body would enter starvation, you would not be losing weight because your body would be inclined to think that food is now scarce. so busting his balls over not eating doesn't apply here.

i'm sure he knows what he is doing, 5 lbs per week can be a bit much, but as long as you are feeling good and eating right then its fine.

make sure you are lifting to gain muscle though, and not just dropping weight.
gaining weight isn't a bad thing, if its the right kind