Aria weight loss not making sense

[lisalever]

Hey, 

So I've been on a diet for 15 days. Across those 15 days I've had a total calorie deficit of 10,353 calories which is an average of -690 calories a day. 

On day 1 my weight was 10 stone 11 and fat percentage 35.5% 
Today my weight is 10 stone 9 and fat percentage 34.9% 

My confusion is when I click across to the lean mass and body fat this is what it says... 
Day 1: 7 stone lean mass, 3 stone 11 body fat 
Today: 6 stone 13 lean mass, 3 stone 10 body fat. 

I'm confused as to why I've not lost more total weight and why I've only lost 1 pound of body fat despite such a big calorie deficit. 

Btw, I've been running, doing pilates (added weights this week) and upped my protein intake so that protein is 20%-30% of my calories, previously it was more like 10%. 

My total macronutrients look like this on a good day which is like 5/6 days of the week: 
Carbs: 37% 
Fat: 27% 
Protein: 36%

Are the scales useless? I'm really not sure how accurate they are and how much I should be relying on them.

Moderator edit: updated subject for clarity

[JohnnyRow · Accepted solution]

690 calories/day times 15 days = 10350 calories

At 3500 calories per pound, that would be 3 pounds, and you have lost 2, easily within expected error range, though there seems to be some doubt if 3500 calories/pound is really true.

As for body fat %, you can't count on the accuracy to see those differences precisely.

Body fat readings are very sensitive to your body's water content; make sure you weigh same time every day, preferably soon after getting up.

If you're eating right and exercising, trust that the change will come in time.

See How can I get the most accurate reading on my Fitbit scale?