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What all these diets are desperately trying to do is psychologically manipulate you into eating less by playing with your sense of fullness. For weight loss, th
by Almondsetat 1y ago
What all these diets are desperately trying to do is psychologically manipulate you into eating less by playing with your sense of fullness. For weight loss, thermodynamics cannot be beaten: eating at different times and in a different order does not matter.
- flyinglizard 1y agoYou’re assuming the body is a constant machine that metabolizes at a fixed rate but that can’t be true.
- tekla 1y agoUntil the human body becomes capable of creating energy out of nothing, this is irrelevant
- californical 1y agoIt can use different amounts of energy depending on different stimulus. Things like fidgeting and body temperature can make a pretty decent difference
- anon84873628 1y agoJust to add some color for folks, this is referred to as NEAT in the literature: Non-Exercise Activity and Thermogenesis. When caloric intake is reduced, the body can decrease this type of expenditure without the person even realizing it.
- objektif 1y agoVery bad take. What if our bodies adjusts the burn rate based on when we eat when we exercise? if that is true you can potentially eat more and lose more weight.
- tekla 1y agoIrrelevant, energy out > energy in, you lose weight
- HDThoreaun 1y agoenergy out changes though. By focusing only on energy in you miss half the equation
- tekla 1y agoLast time I checked, I don't control my metabolism with a dial. I do control what enters my body through my mouth
- IncreasePosts 1y agoOkay, and energy in affects energy out. What you are saying is true and useless.
- alexey-salmin 1y agoIt's not. Human body can't create energy out of nothing, but it can vary the consumption of energy in a wide range which is very similar in terms of externally observable effects. It's a common story when people start to eat 20% less, continue the same lifestyle and lose exactly zero weight as the result. Their body didn't create 20% of energy out of nothing but it just started to waste less energy as body heat.
- tekla 1y agoIrrelevant, energy out > energy in, you lose weight
- alexey-salmin 1y agoThe latter is true, the former is not. Anything that can influence "energy out" is by your own definition "relevant".
- 827a 1y agoHow are you measuring energy out, such that it can directly influence decisions on how much energy you should be deciding to take in? I promise you: Your methodology is inaccurate.
- iteria 1y agoThey have literally done studies showing that this is a naive take. You might lose weight, but the literal moment you consume more calories your body stores every stray calorie it can and it battles you about loses weight every moment. Your body will save calories to the point of discomfort and ill health. The impacts of extreme calorie deficits last for extremely long times and bias your body towards weight gain. The body is more like a thermostat system. Environmental effects can convince your body to move the temperature/weight up or down, but for both weight gain and weight loss is a battle. Your body tries to maintain it's understood ideal weight. Your body if given a chance and you haven't convinced it to change the thermostat setting, will immediately do all it can to gain/loose weight. This is why crash diets never work. It takes sustained effort to convince your body that it's wrong about your initial weight.
- svnt 1y agoThis is trivially shown to be false. Imagine a system with a background/quiescent energy consumption of 1000kCal/day. Imagine that same system can buffer up to 500kCal for up to 24 hours store excess energy in circulation. Imagine it converts excess energy to stored energy at an efficiency of 50%. Assume activity correlates with marginal energy consumption but also increases in the presence of excess energy. A system such as the one described would have very different behaviors during alternate day fasting (0kCal for 24hrs, 5000kCal for 24hrs) than consuming 2500kCal daily. The human body is more complex than the system I just described, but it is a useful model to consider for this context.
- red_trumpet 1y agoSo, the excess energy in your model is just excreted? Does that also happen in the human body?
- wouldbecouldbe 1y agoYes. On the other spectrum, the body becomes more efficient when moving a lot.
- greysphere 1y agoReal world efficiency factors are in the 90s and basal rates aren't constant. The model you're proposing is too artificial to draw conclusions about fasting over a short timeframe.
- svnt 1y agoThen please provide a more accurate one that supports the opposite and simplistic conclusion that it doesn't matter when you eat what calories.
- rolisz 1y agoUnfortunately calories out is a function of calories in. You eat less calories, your body might start consuming less calories. Also, there are two different pathways for using glucose in the body: aerobic and anaerobic. The aerobic one produces 15x more ATP (cellular level energy) than the anaerobic one. The anaerobic one wastes more as heat. So if for some reason you're in the second one, even though you ingest the same amount of calories, the amount of energy you have usable is much less. So yeah, calories in calories out is true, but it's not really helpful.
- rkomorn 1y ago> So if for some reason you're in the second one, even though you ingest the same amount of calories, the amount of energy you have usable is much less. This is technically true but not particularly relevant. It's quite difficult to be in only anaerobic effort, though (and I'd say pretty ill advised since that basically means stuff like all out sprinting without warmup or cooldown). Higher intensity effort burns more calories than lower intensity (eg [1]). It's just harder to sustain. 1- https://www.webmd.com/fitness-exercise/what-to-know-heart-rate-fat-burning-cardio https://www.webmd.com/fitness-exercise/what-to-know-heart-ra... )
- rolisz 1y agoThiamine deficiency can cause anaerobic usage for example, without having to do intense exercise. Severe insulin resistance is another one. Cancer cells predominantly use anaerobic burning (Warburg effect). Various blocks at mitochondrial level, such as carbon monoxide, can also drive metabolism towards anaerobic pathways.
- ourmandave 1y agoConfirmed by the study of populations of 34 countries. Food — not lack of exercise — fuels obesity, study finds https://www.npr.org/2025/07/24/nx-s1-5477662/diet-exercise-obesity-nutrition https://www.npr.org/2025/07/24/nx-s1-5477662/diet-exercise-o...
- 827a 1y agoCalories in / Calories out might be broadly accurate, but reality is a lot more complicated than that. People are really bad at tracking how many calories they take in. Its impossible to measure how many calories you're actually exerting with exercise. Its even more impossible to measure how many calories you pee, poop, perspire, breathe, and radiate out. Microvariations across your current body state, body temperature, and even the time of day can influence how efficient your gut is at absorbing incoming energy. Some people operate with a goal of a caloric deficit of even something as small as e.g. 200kcal. But because all these things are impossible to measure accurately, a difference of just 10% beyond a daily BMR of 2000kcal isn't just a possibility; its the norm. You run for an hour; what if that burns an extra 50kcal that your Apple Watch did not account for? You eat a slice of bread which advertises it contains 80kcal; but it actually contains 100kcal [1]? You sleep poorly, which causes some mild systemic inflammation the next day, which raises your body temperature? [1] https://health.clevelandclinic.org/are-calorie-counts-accurate https://health.clevelandclinic.org/are-calorie-counts-accura...
- testing22321 1y agoThe really cool part is you don’t have to accurately track how many calories go in and out. The proof is in the pudding. If you had a car with a broken gas gauge you would just pump until it overflowed… same idea here. Over a month or so if your weight is stable then you are putting in as many calories as you burn. If you’re gaining weight, you’re consuming more, and if you’re losing weight, you’re consuming less. Adjust accordingly.
- 827a 1y agoSure, but no one can actually do that accurately, for the aforementioned reasons. "I'm gaining weight; I should eat less": How do you structure that in a way that's actually actionable and drive results? Just a general sense that "eh I should eat less"? No one eats consistently enough, or exerts energy consistently enough, to actually make vibe-structuring cal-in/cal-out possible. You might think "I should work out more, that's more calories out" -> but ask literally any runner about how running affects their appetite and you'll realize quickly how wrong that is. Hence: Why diets exist. That is the structure. There are good ones and bad ones. Keto, for example, can work for weight loss not because there's anything particularly interesting about the way your body absorbs carbs versus protein and fat (there are differences, but its not the biggest reason why it can work). It can work for some people because typical protein and fat food sources are less calorically dense (by volume and weight) than carb sources. You may feel full faster; so you may naturally eat fewer calories. Similarly: IF can work for some people because most people cannot physically eat enough to consume massive calorie counts if they time-restrict the hours they're allowed to eat. It also seems to come with some well-studied metabolic effects. You don't have to accurately track inflows and outflows, but vibe-structuring your consumption and exertion habits based on outcomes is a privilege that, sure, some people have, but is not a panacea for every body and mind. Broadly, the people who need to make change who do this will not see the change they wanted.
- IncreasePosts 1y agoThis is an entirely useless thing to say. Your body can make choices, based on what and when and how you eat, that you can't control with your psychology. Your body can raise or lower its temperature. It can put energy towards cell repair or cell reproduction. It can store energy as fat, or signal to burn fat, or build muscle or catabolize muscle.
- calmbonsai 1y agoOh my NO! Just...no. It turns out the body processes different calories very differently depending on a variety of factors including: baseline genetics, time of day, menstrual cycle, prior fasting, current mineral excess/debt, gut flora/fauna biome, and the composition of previously consumed food still remaining the digestive track.
- thiht 1y agoIt’s not just different times though. When doing intermittent fasting you easily ingest less calories overall, skipping a meal doesn’t mean you’ll eat twice as much for the next meal. I don’t understand what’s "desperate" about IF, it’s just an easy way (for some people) to lower their calories intake. It has other benefits and some caveats but it’s one way to get healthier.