The question is how you calculate or define excess. For one, excess calories aren't 100% stored as fat. We're not that efficient.

Additionally the fatter you are the more calories you use at rest. So there's a point where if you consistently eat too much you'll stop gaining weight.

The biggest source of error here will be the calories in the garbage bin though. I wouldn't be surprised if a lot of this is stored in the waste disposal, not the waist disposal.

If I throw away 500 calories of food, I'm not eating an excess 500 calories. Let's not engage in equivocation

If you don't read the main part of my reply, why do you even reply with snarky nastiness.

Assuming a steady surplus of 500, and considering that a kg of human fat is roughly 8000kcal, it will take two weeks to gain a kilo. But a larger person consumes more to simply stay alive so the curve flattens out once a certain mass is reached.

Excess means above what your metabolism consumes. If I'm 200 pounds and my metabolism consumes 3200 calories per day, eating 3200 calories per day isn't 500 calories in excess. Same as if I'm 600 pounds and 4000 calorie metabolism. It isn't excess unless its excess.

Hm, good point

In excess or a normal body's caloric need, not in excess of what you need to maintain your current weight. The latter would lead to infinite growth.

Once you're 140kg, a sedentary lifestyle requires you to take something like 800 more calories as the same person with the same lifestyle at 70kg, to each maintain your weight.

So excess eating of 500 calories over what a normal bodyweight (say 70kg) needs to maintain, leads to fat people (say 110kg) who at some point stop gaining weight and stay at that fat level (of say 110kg).