Energy in, energy out. You lost weight because your ate less than you burned, full stop. IF is just a way to curb hunger until later in the day, so you effectively take in less calories than you normally would.
Why do you believe the calorie in calorie out hypothesis is correct? Do people digest all food equally? If I eat 4,000 calories of olive oil, will I metabolize every last bit of it without waste? Obviously not. But what about different ratios of fats and carbs. After to failing to lose much weight on a low fat diet I had resounding success on a low carb diet, and I can say without a doubt I consumed far more calories on the low carb diet.
> If I eat 4,000 calories of olive oil, will I metabolize every last bit of it without waste? Obviously not.
And if you were 200 meters tall or 5000 years old, the TDEE equations also wouldn't apply to you correctly. Most calorie counting studies are done with intake of "normal" foods, not just pure olive oil. In those circumstances, for the most part, calorie counting works well enough for you to lose weight. Yes, the TDEE equations aren't perfect (and neither are nutritional information labels) but they're all within enough of an error margin for you to be able to comfortably lose a kilo every 2 weeks without breaking a sweat.
It is also true that you should tailor your diet not just for weight loss but also for general health (so cutting calories isn't enough, you should also change your eating habits) -- but weight loss is (for the most part, and the vast majority of people) just a matter of TDEE and counting calories.
> After to failing to lose much weight on a low fat diet I had resounding success on a low carb diet, and I can say without a doubt I consumed far more calories on the low carb diet.
Did you measure the changes in your fat weight? Low-carb diets can cause additional weight loss, which is not actually fat loss because some carbs are stored elsewhere in your body[1,2]. Now, that doesn't mean you didn't lose more weight. It just means that you didn't lose more fat. Whether or not that matters to you is a different question.
I lost 43lbs so obviously it was nearly all fat that I lost. How many people losing drastic amounts of weight on a low carb diet, while consuming more calories than before, would it take to convince you that counting calories is seriously flawed?
Respectfully you are coming from a certain frame. There is always the possibility that other frames exist that may be a more accurate representation of reality. If you are open, check out The Obesity Code by Dr. Jason Fung.
Energy in/out, at least in the sense most people and your grandparent refer to, can be wrong without violating conservation of energy. E.g. if you poop out food from which not all calories have been used.
See, I wouldn't define pooped out unused food as being "in". If you want, you can define it as "in", but then you need to also include the pooped out energy in the "out" column.
Now, a lot of simplification goes on and it’s true food labels are based on heathy digestion. But, that has little to do with the actual definition.
PS: I think this goes back to how the description of how Calorimeter’s are used. Yes, they give a value from burning food, but that’s not the only number being considered.
The solution to this issue is not to start claiming things in violation of thermodynamics. Instead you should call attention to the fact that nutrition labels do not always accurately count the number of bioavailable calories ("calories in"), and that unusual circumstances can drastically change an individual's ability to extract energy from their diet. Rejecting "calories in = calories out" is a distraction from the real challenges, and has the side effect of making you sound much less scientifically credible.
The thermodynamics matter only as much as they are a tautology (which means: not at all), or as an upper bound.
Thermodynamics predict that you'd be better off drinking gasoline (12kcal/gr > fat's 9kcal/gr), and just as well eating wood chips (a carbohydrage) -- even though you get zero energy from either.
"But we're not using calorimeter data, we're using atwater factors"; Well, those actually DO vary from person to person, IIRC as much as 50%; and other things also matter (e.g., adding activated carbon to your food will result in less energy extracted in general; using Ally would result in less energy extracted from fat).
And that's just for the "calories in" part; metabolic rate can also vary as much as 80% along time and between people, depending on muscle volume, or other random, less understood factors - so without a proper measurement chamber you don't know the "calories out" either.
The food labels and general activity tables serve as a good general approximation that describes probably 80% of the public quite well. But invoking thermodynamics (except as an upper bound for calories in) is not justified by our current understanding of metabolism.
> But invoking thermodynamics (except as an upper bound for calories in) is not justified by our current understanding of metabolism.
The problem is when people claim that they can lose weight without running a calorie deficit. This is what's obviously wrong, and it is completely fair to invoke thermodynamics as a way to immediately and soundly refute such claims. When someone claims to have anecdotal evidence of losing weight while not running a calorie deficit, the error is not with the "calories in = calories out" equation but with their poor accounting of where the calories are going.
In my experience, people who promote their pet dieting theories (especially ones that promise dramatic weight loss without requiring exercise) using thermodynamically impossible claims are far more prevalent than people who mean lab calorimeter data when they talk about the calorie content of their food. Your comments about gasoline and wood chips are an insulting straw man, because nobody is ever referring to those numbers in a casual context. They're talking about the calorie numbers that can be found on nutrition labels, and those are meant to approximate metabolisable energy, not heat of combustion.
> The problem is when people claim that they can lose weight without running a calorie deficit.
Of course people can lose weight without running a calorie deficit. It's a commonplace experience nowadays, and absolutely trivial to demonstrate. You can test if for yourself if you are even slightly interested in checking the validity of your theories.
The death of the ridiculous thermodynamic model of human nutrition can't come soon enough.
I agree about the prevalence of pet theory, but my example wasn’t a strawman.
Your thermodynamic argument involves values that you take on faith (Atwater factors) which have been shown to have 50% variance, and values like BMR that also have 50% variance. As a result, invoking thermodynamic impossibility is not justified.
I agree with the gist of what you are saying - but not with the validity of the thermodynamic reasoning as proof.
> Your thermodynamic argument involves values that you take on faith (Atwater factors) which have been shown to have 50% variance, and values like BMR that also have 50% variance.
No, it really doesn't. Just look at the sibling comment that claims once again that it's possible to lose weight without a calorie deficit. That statement is wrong no matter how good or bad an approximation you have of what fraction of the heat of combustion is metabolisable.
If someone believes that they are losing weight while eating a diet whose nutrition labels indicate a much higher calorie count than their estimated calorie expenditures, then it's obviously wrong for them to claim that they are not running a calorie deficit. Instead, the reasonable and scientifically valid claim they could make would be that they are metabolising a much smaller portion of that diet than a normal person would, and thus they are running a calorie deficit because lots of calories pass through them unabsorbed.
Yes. Thermodynamic principles are tautological in the sense you just described and arguing against them isn’t helpful.
However, as the GP claimed the “gasoline is a strawman”, and “that’s not what people refer to when counting calories”; these two cannot live together with a thermodynamic argument in any useful sense, because it amounts to “well, if your food labels say a number higher than your exercise machine and BMR, the your numbers are wrong for reasons I cannot point to”, that’s about as helpful as a religious argument.
You can lose weight easily without caloric deficit in any sense - water weight (limited amount of course). There are several other ways in which the body loses fat - e.g. through the skin and scalp (negligible amount for most people, but not all people).
Invoking thermodynamics as an end-all be—all argument is dishonest even if it is a useful approximation.
It’s very useful when studying diets. There are meaningful differences between undigested calories, excreted calories in urine or Methane, and increased metabolism. For example increased metabolism resulted in extra body heat which needs to be removed.
Water weight is similarly important and still conserved in terms of energy. It might seem meaningless to you, but an athlete who wants to stay at absolute peak performance may want a more accurate picture of what’s going on.
Of course, but in this case we can only measure energy intake, and only semi-accurately (not everybody metabolizes every food 100% efficiently).
The body is known for up-regulating and down-regulating energy expenditure based on a wide variety of factors, especially blood sugar level. So what you eat matters as much as how much you eat.
'Calories in, calories out' has been pretty widely debunked - at best it's part of the story. More important is meal timing (i.e. fasting), resting insulin levels, the source of those calories, etc.
Not OP, but the general logic behind "calories in = calories out" is obviously fine. However, just knowing this doesn't really tell you anything about the best way to go about decreasing "calories in" or increasing "calories out" in a way that will result in meaningful fat loss and improved health. For example, it is plausible that someone could reduce "calories in" by eating less and their body could make up the difference by reducing "calories out" via lower BMR instead of having "calories out" remain constant with the difference being made up by burning fat stores. Maybe some fat loss will occur initially at the expense of being more tired and hungry but this change eventually becomes unsustainable/unhealthy if they aren't eating the right foods.
On the flipside, you can increase calories out by exercising but you could end up starving and/or exhausted as your body tries to compensate for the increased activity, depending on what is going on in your body hormonally. Or you just have no energy to spare for exercise as it is right now, and have a very hard time getting in to an exercise routine. All this is to say that "calories in = calories out" is all fine, but these variables are not independent. Having some knowledge of how and when the human body burns fat and when it stores fat goes a long way in coming up with a strategy to lose weight. This is where these trends of low carb diets and (intermittent) fasting have originated from.
You nerd to get a new Dr. or nutritionist if that's what they told you. If you just got that from rando internet bro science you should talk to a Dr. or nutritionist or try to back your statement up with some clinical research.
Different energy sources metabolize differently, so energy in, energy out is technically correct, but not very useful in real life. Additionally, as others have mentioned, there are other factors which affect how the energy in is handled or metabolized besides just the pure energy you consume.
This is misinformation that ignores the findings on gut biomes (and how they affect both our body and brain), how different foods affect insulin sensitivity, psychology, and other factors like effort and convenience. IF isn't "just" a way to curb hunger.
You didn't contradict the person you responded to, if you consider "calorie counting is a myth" to mean that calorie counting doesn't help you lose weight.
