He consumes 2500+1000=<<2500+1000=3500>>3500 calories on Saturday
He consumes 2500*6+3500=<<2500*6+3500=18500>>18500 calories in the week.
He burns 3000*7=<<3000*7=21000>>21000 calories in the week
His caloric deficit is 21000-18500=<<21000-18500=2500>>2500 calories per week
#### 2500