Congrats Michel! That is such a good achievement to go from 80kg to 73kg in a year. It truly is! I (Sam) am much younger and I went from 75kg to 72kg in 22 months... only 3kgs... although, it was mixture of weight training to gain muscle mass and an up and down diet, so you are truly committed.
Hope you can be apart of the @actifit family soon by using the app (available on Android or iPhone) to count your steps and post it to the Steem blockchain! Get AFIT tokens (future SMTs) for 'proof of activity' (5,000 steps minimum to be a part of the daily rewards pool). You can also delegate if you want to get rewarded with daily tokens! Give it a check, if you haven't already :)