Calories in/out is a misleading and insufficient description. It is not an explanation with any predictive value. The majority of weight in a human body is tied up in molecules which have no biologically meaningful caloric content: water and minerals. Instead of trying to affect mass by tracking energy, try affecting mass with mass. Or stay with your energy equations; but stop weighing in.
We have a societal fixation on weighing our bodies. The people I know who obsess the most over this don’t weigh the water they drink or food they eat. They may tabulate calories; but they can’t tell me the weight they’ve added to their system in a week. Cool. You suppose a potential energy unit is going to dictate mass transfer while you have no idea how much mass you’ve added and subtracted from the system? That’s cute.
If you don’t know how much mass you’re adding, why are you weighing in at all? If the weight of your food and the weight of your water is all over the place while you think you’re controlling the energy equation, I’ve got news for you.
But a pound of fat has 3,500 kcal, so it should be a real straight-forward approach, right? Nope. It takes more than the potential energy in a substance to convert that substance to something else. The estimates for using up a pound of fat are in excess of 4,000 kcal.
However, as your body tries to lose this mass, applying around 4,200 kcal to loss of tissue, what happens if every day the human animal adds four pounds of mass to the system: 24 ounces of food and 40 ounces of fluid? This is light eating by American standards, by the way.
That is, your efforts to lose weight may be removing a whopping 1.5 kilograms of mass per day while you’re adding 3 kilos to the same system. While it’s true that not every kilo is the same (5lbs of water and cucumbers will not be kept as mass in the body at even remotely close to .5lbs of sugar), if you don’t even look at the mass going in versus the mass going out, why bother checking the mass of the human? Your body will do everything it can to adjust metabolic rate to less than your caloric intake. But it CANNOT create mass out of nothing.
This is where even macro tracking breaks down. One, without our own lab and bomb calorimetry, we don’t know the exact content of a food. Two, your body will adjust energy expenditure to avoid weight loss at all costs.
Thus, in the hardest of troubleshooting, we weigh real food and we weigh water intake. We standardize it. We trim it back.
The fastest way to lose weight is just starve and NOT exercise: https://www.sciencedirect.com/…/a…/abs/pii/S0003999395805087
Just one week of inactivity can lose 37% of muscle weight and 61% of strength. With no exercise, there’s no stimulus to maintain mass in the system. Voila.
Of course, people don’t want to just lose lean tissue and get fatter as they get lighter. So they do lift. They do workout. Well, then, obviously we have to add some mass to the system to just maintain our musculoskeletal system and organs. How much? Research says, at least 1.2 grams of protein per kilo of body mass. In a lean meat, for a 220lb person, this is just around 1.5lbs of protein-dense food. With water regularized at 64 ounces per day (4lbs), that person has to remove over 5.5lbs of mass from the system per day to see “weightloss.”
How much mass do you bring in, keep, and remove per day? You don’t know? Then don’t weigh yourself. Once you have even a pretty decent approximation, you still won’t need to weigh in, because you can predict.