Comment by shapefrog

So as a teenager, I was carrying 5-10kg of books and walking back and forth between classes every 40 mins.

As an undergrad I was travelling across campus multiple times a day, spent hours on my feet in labs, did multiple heavy grocery shuttles and also spent a lot of time partying.

In my first job, I could be sat in the same spot for 8-10 hours without moving.

A year in to my first job I had added 15kg (~30lbs ~2stone) - while consuming way less food and alcohol than my university days.