Question: Roughly how much energy do you use up in a day?

Gavin Devereux answered on 16 Mar 2012:

Hello. Sorry for the slight delay in getting back to you.

It depends (massively so), on how physically active you are. For example, if you’re an elite endurance athlete, you’ll do so much training that you’d need to consume enormous amounts of energy to fuel it. If someone who was not physically active (and so didn’t need as much energy) ate the same amounts, they’d quickly gain body fat.

As a really rough idea, an adult will typically use up 1800 to 2500 kilocalories in a day (that’s just normal daily activites). Add on any exercise, and you use more (some athletes eat/drink 7000 to 8000 kilocalories per day).