People who don't know you really should keep their opinions to themselves!
If it's only a few kilos then you can probably do something about it by eating less. It's not always easy though. It was easy for me a few years ago because of an unpleasant event in my life but it still took me a year of not eating much to go down from 85 kg to 75 kg, getting me just inside the NHS healthy weight range for my height and age. My 'trick' for keeping the weight down is to eat most of my meals from smaller than normal plates.
I wish you luck whatever you decide to do whether it is calorie restriction or telling the insulting busybodies to keep their opinions to themselves.