I agree. My argument is that if your calories from food equal your energy expenditure over a given time period, and then you eat a single celery stalk, then the

I agree. My argument is that if your calories from food equal your energy expenditure over a given time period, and then you eat a single celery stalk, then the energy from the celery will "fatten" you (and/or contribute to muscle protein synthesis if you exercise). Conversely, if you ate nothing but cookies, but the total energy of those cookies was below what your body expended, then your body will necessarily make up for it by dipping into your fat reserves. Hence why labelling foods as "fattening" or "not fattening" is inaccurate.