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).
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).