Ive never been into calorie counting - over the years Ive monitored my weight on a weekly basis - however last month I started calories counting - not so much to lose weight but to install some discipline into what i was eating - I had recently got into a tendency to - see it - eat it - favorite crisps and buns - as a basis I used the calorie count from my Polar V800 as my "daily target" (tests ive read indicate Garmin and Polar despite using different algorithms/methods to calculate calories are probably the best but tend to indicate around a 12% over estimate of Calorie consumption) and the values given for foods off the net and on packaging plus when required my scales - as an Engineer I like data so compiled a spreadsheet to record weekly food consumption and another one to record calorie and weight balance since i started
Ive lost around 3kg in the last month without dieting per.se. - daily estimates of my calorie requirement from the V800 are in the range 2100 to 2900 depending on how much "activity" I undertake - on average 43 minutes a day in the gym (From another spreadsheet

) doing mainly resistance training and average just over 2500 which for a geezer is around the recommended daily intake - calorie consumption has varied a lot more - good days and bad days - but has averaged around a deficit of just 200 calories/day
Doing the arithmetic it would seem that calorie counting for me has attributed to a weight loss of 3kg without much hardship - notwithstanding this there does seem to be a glaring disparity between the amount of weight i've lost and my calorie deficit as calculated by the Polar.