My weight loss has been stalled for a couple of months now, and it seems to me that no matter what else is going on with my surgery, my diet, my exercise, etc., this follows my appetite. Sometimes I go a week where my appetite is much lower and I lose weight the following week; sometimes it's higher, I feel a need to snack a lot, and even if I resist that urge my weight still holds steady that week.
I've long believed that the idea that your weight loss tracks "your calorie intake minus your calorie expenditure" is not just overly simplistic, it's almost dangerously inaccurate. Sure, it's mostly technically true, but only the same way your weight loss equals the mass of what you eat minus what you poop (what with conservation of mass and all). Focusing on weighing your bathroom visits to decide how much you can eat is not going to help you lose weight.
So many people look at the calorie formula and get despondent and discouraged. I just did an hour on the treadmill and it means I can eat an apple? That's what the typical dietitian formula tells you. Not only is it discouraging, it's not really accurate. The fact is, the work your body goes through to stay alive every day is so many calories that the extra from you walking a half hour is almost rounding error. You burn more than that having your brain's neurons fire, or pumping your lungs, or rebuilding your stomach lining, or pushing blood through your liver. You won't make a real change to the balance sheet of today by doing a few sit-ups.
Nor is that the real reason why exercise matters. The real point of exercise is not to affect the balance sheet for today: it's to change the formula for the next week, or month, or year, or decade. Exercise changes your metabolism. It changes your appetite. It changes how much your body will burn tomorrow to make its heart beat and its neurons fire. It changes how good your body will be at processing food. It changes how much energy it'll conserve versus how much it'll use up.
Over the holidays I might have eaten more food I shouldn't, and that changes the formula too. I definitely need to stop that. But mostly I slacked off on exercise. Doing that won't change the formula back the next day, but it will eventually. Probably I have a few weeks of getting back onto the horse before it'll start to show real results.
I also am working on having more snacks be high-protein and low-calorie. I need a good source of plentiful cheap edamame now that Big Lots is out of it!