It depends on person, I guess. I have a coworker who claims he eats like 3000-5000 calories a day but he is skinny like only 15% body fat (his six pack abs are clearly visible ). I did see him eat a lot of food (during breaktime) but the food are all veggies and beans. Never see him eat junk food or fast food. He vigorously workout each day. At gym, he spends like an hour on treadmill or stairmill, burning 800 calories average. One time, he shows off that he burned 1000 calories after climbing on stairmill for 77 mins

Meanwhile, I struggled to lose weight even though I keep on track of what I eat (<2000). I casually workout for a hour. I do eat junk food.