Comment by lordnacho

Just a simple scan of some foods and some exercise calorie amounts and times should show it.

Reasonably tiring exercise on a bike could burn 10 Cal per minute, so maybe 600 an hour. But swallowing a few packs of crisps or a few chocolate bars could fill that right back up in a couple of minutes. If you were speed eating you could swallow it in under a minute.

Think about if your weight is steady, how long you spend eating and how long you spend using energy. It can easily be the case that you spent all your calories in 23.5 hours and were eating for just half an hour.

The time ratio is so lopsided it's hard to come up with a plan where exercise carries most of the weight loss vs just eating less.

If you think of your energy use as base rate plus exercise rate, because your base rate is sustained for the whole day you'd have to exercise like crazy for a long time to make up any difference to what you eat.