Metabolism Reset

I read an article by Jillian Michaels and she suggests eating 1400 calories a day for 4 weeks with 5 hours of exercise per week to reset metabolism. She said that one wouldn't lose weight during this time but no gain should occur and that after the 4 weeks,weight would start coming off again. Any thoughts? I am afraid to eat this much but I do not see the scale moving with how I am eating now which is about 1200-1300 per day with daily walking and cross training. My clothes fit the same way as when I was 10 lbs. lighter so I think I have built muscle. I know I shouldn't be concerned about the scale but I am conditioned to do so!