Jawbone calorie deficit changing

maseface1

Hi, I recently bought a jawbone up24 which I'm really liking but I'm confused slightly by the calorie deficit it is recommending. I log my food in MFP and sync it which all works great. But my goal calorie deficit changes throughout the day. I would like it to be 500 but it normally starts in the 300s then this evening it's 211!

Can anyone give me any advice about whether I can change this? I can obviously just do the myths but it would be much better if the app was just consistent about it.