Energy Compensation and Adiposity in Humans
sciencedirect.com
sciencedirect.com
If you want to lose weight, calories out must be > calories in.
This is obviously true.
No one is going to break thermodynamic laws. But it fails to appreciate the gigantic black box that is our metabolism. I have often felt that there may be compensatory changes made to the metabolic activity (of some people) in response to changes in exercise, changes in diet, etc. You might "swallow" 2000 calories, but that doesn't mean your body will necessarily extract all 2000 calories under all circumstances.
Although this study is far from perfect, I think it lends support to the notion that counting calories consumed and expended is often overly simplistic.
Metabolism isn’t really a black box. Millions of years of evolution have made us quite good at absorbing nutrients from food and using them conservatively.
Our bodies won’t ignore ingested calories or burn excess calories for no good reason. If the body can absorb the nutrients, it will. If the body doesn’t have to burn calories to continue existing, it won’t.
Evolutionarily, it wouldn’t make sense for our systems to evolve features that discard ingested calories or burn calories without good reason. Food wasn’t plentiful for the vast majority of our evolution.
What actually happens is the person’s behavior changes: Many people adopt exercise programs but then eat more calories. Or they reduce caloric input but then spend more time resting. Or they cook smaller meals but eat more snacks and treats (which often go unreported in self-reported caloric intake studies)
But there isn’t a condition where everything stays the same but the body suddenly decides it needs fewer calories to accomplish the same goals. That would imply the body has various degrees of inefficiency that can change over time, which isn’t really true.
Carbs break down to sugars which trigger the release of insulin. However, cells can become insulin resistant to varying degrees, causing their muscles and organs to reject the free-floating sugars in the bloodstream.
When that happens, your body fat gets to preferentially consume as much of the sugars as possible and then the kidneys filter out the excess. When this happens you end up with an undernourished body that doesn't process all of the calories in the food and that gains body fat preferentially to anything else.
That body fat then becomes a hormone regulator, affecting mood and energy levels even further.
There's so much that goes on in the body that isn't explained by calories in > calories out that, if not properly understood, can massively increase the difficulty of losing body-fat weight, (the body puts on fat over feeding its organs, the body doesn't get the nutrition it consumes to the cells that need it, the person is tired and eats too much to compensate, the list goes on I'm sure.)
Recognizing that not becoming overweight in the first place is the ideal solution, but failing that ideal solution the follow up isn't as simple as "don't eat so much" is a better approach to take. Medical science has not cracked the code yet, but I'm willing to bet that someday soon we will find a solution that breaks this cycle, and when we do obesity and overeating will drastically reduce so that only the people with mental or emotional overeating issues will remain in the obese category.
Metabolic syndrome is a severe exception, though. It’s not something that happens to average people eating normal amounts of calories.
There are always exceptions in disease states, but those exceptions are invoked far too frequently in conversations about typical people on normal (not chronically hyper caloric or extremely sugar heavy) diets.
Despite that, I've lost almost 100lbs from dieting (intermittent fasting, ECA stack, even Keto for a while) over the last several years but I'm still trapped by the condition as the less I weigh the worse the syndrome gets. Increased hunger, depression, lethargy, exhaustion, body temperature decreasing (painfully cold hands even in the middle of summer), insomnia, irritability, all of these issues hit me at the same time and get worse the lower my weight goes.
I don't have diabetes, blood sugar and a1c are normal, no hypertension (actually hypotensive), generally decent health otherwise. Diabetes and excess fat isn't the disease, it's the visible symptom of a larger issue caused by the American diet and lifestyle. Sure, it's my fault (and my parent's fault) that I became obese as a child but now the typical solutions for the issue simply do not work, and people who refuse to see that there is more going on than simply "fat pigs won't stop eating" do literally less than nothing to help solve or identify the core issues.
The food control / prevention of overeating solution works to prevent people from ending up like this, but rarely works to solve the issue once it has taken root, not to mention that the body typically doesn't lose fat cells once they have been created so even if you get to a normal weight you basically have a human fat cell parasite hungrily clawing at every morsel of food you eat more than what you immediately need permanently attached to your body unless you undergo surgeries to physically excise it from your body. (This is one of the reasons why most contestants on the Biggest Loser end up regaining their weight within a short amount of time, for instance. It's far easier to refill empty fat cells than it is for fat cells to be built by the body.)
This is why obesity is a crisis. Not just because of diabetes, but because the tools that we have to fight obesity once it arrives are insufficient for the job.
I don't understand the argument. I agree with you that the human body seems to have several mechanisms (in terms of behavior changes) for reducing food consumption and/or up-regulating calorie expenditure to avoid gaining excess weight. And presumably there were excellent evolutionary reasons for humans to evolve these mechanisms, even though food was often in short supply! (As someone who has spent time trying to do physical activity while overweight, I can attest to this.)
But then you say that it wouldn't make sense for humans to evolve other physical mechanisms (such as changing digestion efficiency, fat storage efficiency) to accomplish those same well-motivated goals. Why not? I'm genuinely curious.
First, exercise. You cannot outrun your fork. Exercise is essential to your health, your longevity, your quality of life, and your weight. No one can lead a good life without regular, healthful exercise. Everyone should find some activity that they enjoy doing so that they are motivated to do it regularly. That said, hours of exercise calories can be eaten easily and mindlessly in moments. Bodies are evolved to survive in the wild and are very efficient. A handful of cookies can power you to walk for miles.
So, second, diet. Different kinds of foods affect you in different ways. Food composition is important to your metabolism on both a molecular and cellular level. Molecularly, you need specific nutrients for health. But, additionally, food affects you based on its cellular form. So, eating whole broccoli is more taxing for your body to digest. The whole plant fibers act as food for commensal bacteria. Sugars packaged in intact cell walls are absorbed more slowly, and produce smaller hormonal responses in the body.
The biggest problem everywhere are so-called highly-palatable foods. Candy, sweetbreads, soda, smoothies, white flour products, pop-tarts. These food-like substances come in what is effectively a partially digested state. Your body integrates their calories almost instantly. They feed festering bacteria rather than beneficial bacteria. Everywhere these foods are introduced, obesity is the result.
Current nutritional research is woefully inadequate. The best studies, controlled environment studies, are heinously expensive and impossible over the course of years. Furthermore, the provision of funds for nutritional research is primarily done by biased, interested parties, so much of it is colored by funding sources.
I invite you to examine the evidence presented by those such as Dr Greger: https://nutritionfacts.org/
And I encourage you to look into this yourself.
Our way of assessing food's caloric values are also imprecise. We act like all carbs and protein are 4kcal/g and all fat is 9kcal/g, but there is clearly some level of variation, some of it due to food and some due to individual. And of course we don't know for most ingredients how much of each macro and how much water they _actually_ have, we just use mostly-ancient reference values.
All of that said, when we accurately track the amount of food people are eating, their weight does pretty predictably move with the calories in almost all circumstances. A lot of folks think they had other experiences, but people are really, really bad at accurately tracking their food intake. Shockingly bad, even when they're clearly trying.
Similarly, when we measure people's oxygen usage, it tracks fairly predictably with weight changes, suggesting that we don't see outsized changes in 'metabolism' defeating folks.
That still doesn't answer the question of why this is all happening.
This is only true in the short term - days,weeks. What is observed in the long term is that people, even the overweight and obese, reach stable weights without changing their lifestyle. So, if I were to start eating a surplus of 1000Cal/day compared to my current diet, and without changing my lifestyle in any other way, i would gain weight quickly until reaching some other significantly higher weight level, and then plateau there until I change other aspects of my lifestyle.
This may be due in part to simple energy calculations (I need more energy to move around a higher mass), but is likely also affected by other metabolic factors as well (e.g. I would also develop stronger muscles to hold my bigger weight, and stronger muscles directly need more calories to be maintained).
It's also extremely important, when discussing practical weight loss, to remember that appetite is also directly controlled by your body chemistry, and may vary wildly between people, probably explaining a huge amount of the observed weight differences.
humans (or other animals, because this problem is not unique to humans) gain weight because they consume more calories than they burn
is like saying that
planes crash because the force of gravity became stronger than the lift generated by the wings.
An obvious physical truism, but it gets you nowhere on the field of disaster. And if you do not dig further into the problem (pilot error? machine malfunction? controlled flight into terrain?), you won't be able to prevent future disasters.
For starters, short of outright starvation (0 is certainly 0), we do not even know how many calories we eat, and we might never be able to find out. The values written on the packaging are measured by burning said food in calorimeters, but our bodies aren't calorimeters and there is a huge systemic error, perhaps 30 per cent. Even chewing the food longer can increase the total calorie intake from the same meal.
Personally, I had reasonable and sustainable results with intermittent fasting. Blood pressure normalized, waistline diminished, though not to the point of having a sixpack. But I didn't have the same sustainable results with generic calorie restriction and 5 meals a day. I was miserable, cold and felt hungry all the time. That is not life.
None of those bad effects seem to be present on IF.
Actual nutrition -- getting the right micronutrients and such -- is the most questionable part of my interpretation, but it can still feel true to someone, they can still feel like their body just isn't getting what it's telling them it needs to feel right.
I agree that _many_ people can be delusional about their caloric intake (and their activity), but my suspicion is that calories-in/calories-out is messier than the simple thermodynamic argument.
Here's a great example: my husband has been focusing on weight loss for the past few months because he feels best at a certain weight. He had been using "zero-calorie" cooking spray, reasoning that "regular oil" had more calories. I warned him that it was advertising and that it's just regular oil that is 1/n (just checked and n=753) serving size to allow them to say it was 0 calories per serving. He didn't believe it.
He plateaued with his weight loss and couldn't figure out how a 2500, 2500, 3500 diet was no longer giving him the expected results. Until he cut out the "zero-calorie" cooking spray.
No one sprays that cooking spray for only 250ms.
For what it's worth...
Part of my original comment is based on the fact that I have been _carefully_ monitoring my food intake AND activity for the past 18 months.
I will tell you over that period, I wake up and weigh myself. Each morning, my scale says that I weigh between 166.6 and 168.0--without fail.
I measure my food with a scale, but I will _also_ tell you that my caloric intake varies between 1800 and 2600 calories per day.
My activity varies as well (I won't go into details).
But my weight is PINNED to 167 pounds. Day after day after day.
To me, this information just screams that my body is modulating its caloric intake based on what I eat and how active I am.
Now, I know, this is "anecdata." But I can't be the only person who has observed this.
The real problem is that eating less is HARD. I have the utmost sympathy for people who struggle to eat less. I think it's great that we have many strategies to eat less, I hope that we develop more strategies and more effective strategies, and I wish everyone luck in their search.
I think it's actively counterproductive to say that "eat fewer calories" isn't the goal, though. Calories should be a first stop for measuring the efficacy of your strategies. Getting rid of your primary measuring stick is madness. If "CICO Sucks" claimants came armed with better measuring sticks, sure, they would have a point, but they generally don't, meaning their actual proposal is to discard the yardstick, which is madness. How do you hope to find an effective strategy if you can't measure the efficacy of your strategy?
Good: "De-rate exercise calories by 50% due to compensation."
Ok: "Count your calories."
Bad: ...
Really Bad: "CICO sucks, nobody knows anything, so buy my book and try my fad diet!"
To me, all of this is basically fine. If someone finds an effective way to trick themselves into eating fewer calories, that's still a win.
I'm referring here to people who are themselves losing weight, not the hucksters.
I do not have diabetes, my a1c is perfect, my resting heart rate is typically in the low 60s, the highest my blood pressure has ever been tested was 127/89 and the lowest has been 87/65 (pre-hypotensive).
I guess what I am trying to say is that human metabolism is not standardized and does not fit into a single conceptual block. I would have to actively exercise for a 30 minutes a day or more to equal out the calories burned by someone with a normal metabolism who sat on their ass all day.
But you're still onto something else that varies with exercise, changes in diet, etc. It's called NEAT, which the article briefly mentions. It's why increasing your cardio won't linearly increase your fat loss. See a basic overview here: https://builtwithscience.com/non-exercise-activity-thermogen...
This is an honest question. I've never understood this.
There's a lot of other factors to consider... exercise and type of exercise, macronutrient breakdown, how large the surplus is, etc.
edit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5786199/ have a look at this, it shows that hypercaloric diets will produce weight gain, and macronutrients have an effect on composition.
Again, lot of other factors at play here, have a look at the linked paper.
Also, regardless of what the body's primary storage mechanism is, it's just obviously true that adult mammals experience changes in the amount of protein stored on their bodies on the same timescales as weight gain and loss occurs. Anyone who has ever started or stopped an exercise regime has experienced this.
The study is evidence that macronutrient composition has an effect on how much fat you gain, and I gave some reasoning for why this is the case. If you're not convinced then I suggest you do some more digging, I don't have time to find the all relevant papers for you.
> it's just obviously true that adult mammals experience changes in the amount of protein stored on their bodies on the same timescales as weight gain and loss occurs.
The body has both catabolic and anabolic processes running concurrently all the time, you'll see increase in one kind of tissue when overall one of these processes is more active than the other. caloric intake and macronutrient breakdown obviously affect these processes, as does exercise.
Essentially, I think people misjudge how much of an effect metabolism plays compared to other factors, misreporting or miscalculating caloric intake, self deception, etc.
Body composition is another thing entirely and involves going a layer deeper to macronutrient breakdowns and exercise variants.
https://www.sciencedaily.com/releases/2015/11/151119133230.h...
> Energy intake along the spectrum of physical activity levels (inactive to highly active) appears to be J-shaped, with low levels of physical activity leading to dysregulated appetite and a mismatch between energy intake and expenditure. At higher levels, habitual physical activity influences homeostatic appetite control in a dual-process action by increasing the drive to eat through greater energy expenditure, but also by enhancing post-meal satiety, allowing energy intake to better match energy expenditure in response to hunger and satiety signals.
So, if you want to lose body fat, you probably shouldn't focus on getting hours and hours of cardio in (unless you enjoy it), but you really should be doing some amount of physical activity on most days.
> a long-term increase in activity does not directly translate into an increase in total energy expenditure
But they argue from a correlational study. This cannot establish that an intervention to increase activity would not lead to an increase in energy expenditure. Something like the Lucas Critique[1] applies to the human body and any adaptive system: once you make an intervention, the system might adapt in ways that don’t reflect correlational data from before the intervention.
You need the ward, of course, to prove what works and what doesn't under perfect conditions. But you also have to figure out how to export those conditions from the ward.
Also, I've known several obese people during my life who exercise. Some of them I would never even see eating but cycled to work every day and it's a mystery how they remain so large.
This further backs up what a lot of people already know: losing weight is mostly about eating less, not exercising more. Exercising is good but we should really break the association with weight loss. Most fat people I know who adopted exercise just ended up eating even more than they did before which is only going to have a negative overall effect.
Unfortunately, the idea of jogging and sweating in the gym is more glamorous and easier to sell than hunger.
You need to have a calorie deficit of about 3500 to lose a pound of weight.
Running a mile in about 20 minutes is about 200 calories.
So you would need to run 17.5 miles over 5 hours and 50 minutes to lose 1 pound. So running about 50 minutes a day, you could lose a pound a week if you don't change your eating habits.
Alternatively, if you eat 500 calories less a day, you would also lose a pound a week. You can probably do that just by skipping a part of a meal, cutting out snacking, or not drinking sweetened drinks.
Our bodies seem too complex for any simple diet or exercise fad to be the key, it really is just about showing up and iterating over what works and what doesn't and tweaking things to find your unique routine. You never win and eventually you die, but I guess it beats getting obese and sick.
Most people will feel more energetic after improving their diets and adding physical activity.
If someone is feeling too drained to function or is suffering from their plan, they’re either working out too much for their current fitness level or they’ve restricted calories too much.
It’s more important to focus on small, sustainable changes. The people who try to go from couch potato to CrossFit hero or who try 1000-Calorie restrictive diets are the people who burn out and give up. The people who start by walking 10 minutes per day and slowly increase their activity or who begin by cutting out 50 calories per day are the ones who see long-term progress.
People also just like to blow things out of proportion and go to extremes. Can't have any carbs or you'll be out of ketosis! Can't have that lemon juice in your water or you'll be thrown out of your fast! Yes, people do believe those things despite never having actually tested those theories themselves.
If there's one nearly universal "rule" I've learned about nutrition and weight loss (both of which I am obsessed with), it's that most approaches have a benefit at a hormetic level. Vegan diets, paleo, Mediterranean, keto, South Beach, potato famine, fasting, etc., all can work but all can also detract when pushed beyond a threshold. Hell, even a certain amount of sugar in one's diet is perfectly fine and has a benefit at its hormetic threshold.
The same can be said of exercise. Exercise has benefits, but it's often highly overrated. The primary benefits can be achieved at an incredibly low level. You don't need to run on a regular basis or lift heavy weights unless you enjoy it and find a benefit. To go beyond a certain point means compromising the longevity of your joints, providing negative feedback to your psychology rather than positive, overloading your CNS, and having elevated levels of cortisol.
In fact, for people trying to lose significant weight, anything beyond walking is likely to be a waste of time until they reach their target. Exercise is not an efficient way of burning calories compared to simply not eating those calories, burns more glycogen than fat most of the time (unless you really elevate your heart rate), and raises cortisol which is counter to burning body fat. Worse yet, many people go to the gym after work because they either need to lose weight or think that they've "just got to", but raising cortisol in the evening is usually counter to getting quality sleep or getting to sleep on time. If you don't get good sleep, you're detracting from getting to a better body fat percentage and staying there.
Also, I would need to see some data that an average person is going to be able to build enough muscle while losing body fat to add on an extra 1000 calories to their RMR. I'm not saying you're wrong, but I'm skeptical based on my knowledge. In fact, I would pretty much say "no way" unless one can stay anabolic and dedicated enough to build an above average amount of muscle.
Have a look at this paper using your favorite hub of science.
doi:10.1097/00075197-200103000-00011
https://journals.lww.com/co-clinicalnutrition/Abstract/2001/...
Based on this, a pound of muscle has a REE ~6 kCal per day.
So to get to the number you are suggesting, a person would have to put on ~166 lbs of muscle. That's not realistic most people, let alone those with plenty of fat to lose. It also takes a lot of time and money (calories = cash).
A person could work out that muscle and burn more calories, but there's a few problems with this as a fat loss approach. For one, you're going to need a lot of glucose to have a meaningful workout so you're already undermining fat utilization. Second, it takes time to build up that kind of muscle. It's both a short and long term time suck.
Let's say an average-sized person puts on that amount of muscle and utilizes all of it during a 60 minute body building workout:
6 METS x 3.5 x 75kg ÷ 200 x 60 mins = 472.5 calories
While that's not anything to sneeze at, it hardly matters anyway because muscles don't burn fat. At best you're just preventing the wrong kind of weight gain. To even get to that amount of muscle and keep it on you still have to eat at least enough calories to match that anyway. This is why working out requires more working out, otherwise energy will eventually be stored in the form of fat.
Or, they could literally just not eat that 500 calories and spare themselves the sisyphean task of relentlessly working out and not losing substantial fat mass.
Some resistance training is a good thing no matter what, but expecting muscle to be a weight loss aid doesn't make sense to me. At best, it's an adjunct to fat loss and should be done in intervals.
I'm absolutely open to having my mind blown on this. :)
The hormesis thing in particular is about introducing things in small amounts to get a beneficial response while limiting the harm that can be done in too much excess. Some things have no known hormetic level, lead being a prime example, but generally there's a level of tolerance to most things and beneficial pathways that are triggered by them. This is why when people say "only in moderation", they're only partway correct; moderation to many people usually means an amount of something that is less overtly harmful than average, but hormesis can mean taking in a very small amount of something infrequently depending on the substance and the intended effect. Small amounts of alcohol, for example, can have different benefits for decision making, creativity, and longevity, but the returns diminish rapidly if you either drink too much or consume any amount too often.
The other half of the equation, in relation to my point about adaptation being both positive and negative integers, is keeping the body on its toes, for lack of a better term. A lot of people hit a plateau on a diet because their body has reached a set point for the stress it endures. But occasionally switching up the input causes it to have to have to adjust to dealing with that new input at the current set point it has now reached. This is one reason why some people who have done keto long enough become shocked when they actually lose some weight on a carb binge, and they might even begin to question what they've been doing the whole time. Of course, what they were doing is still right for them if they are in good health because they become fat adapted, thus the body may need to do a certain amount of adjustment in order to start utilizing carbs efficiently again. This doesn't take long, however, since the body still fundamentally needs glucose, so if one were on primarily a keto diet then introducing carbs in brief periods may elicit beneficial responses in more ways than one. Not only can it mean actually dropping a few pounds here or there, but it can be just enough carbs that it improves sleep and allow for more meaningful workouts.
You saw a change in your results not only because you allow yourself a hormetic level of both rigor and relaxation, but you are in a way simulating the environment our ancestors developed in. We didn't develop to exist in equilibrium with our environment, as has been possible thanks to air-conditioning, modern insulation, and agriculture. Living in any particular state too long can mean getting too much of the adaptation we have for that state. Through strict diet and exercise, you are simulating a period of scarcity. When food was scarce or the environment was inhospitable, humans could only eat food that was calorie-thin while expending extra energy in order to solve that scarcity. By taking a few weeks off, which goes against the advice of many in the fitness industry, you are then simulating the time of good weather and good harvest. The body did all it needed to do during hard times, now it needs to shift mechanisms for the current environment. This fluctuation works because, if hard times go on too long, relying too heavily on our long-term energy stores can pose a threat to our survival; the solution is to reduce energy expenditure that occurs beyond BMR, limiting the amount of glycogen expended on excess movement, and focus that both glycogen and triglycerides on getting used to a harsh environment with no end in sight. In contrast, living like it's summer in California all year round, while having certain anabolic benefits and a good way to store up energy for the next period of scarcity, can result in negative health outcomes because our bodies are neither used to modern bounty nor are willing to pass up on an opportunity to store fat for the harsh winter that never comes.
So yes, hypothetically, there's a right amount of flux in exercise and relaxation that has a greater benefit than either of them alone.
At some point soon I need to research more of the evidence for or against this concept because I've become particularly enamored with the whole idea of hormesis as of late. It's biological in the strictest sense of the definition, but I've applied it to more aspects of my life than just diet and exercise. For instance, I rarely watch TV or engage in entertainment anymore, but I have also realized that just a little bit of either one is good for the mind and the soul. There are periods where I go through an "entertainment famine" where I simply don't watch/play any of it, and then I'll have a few weeks where I play a game or watch an old show I appreciate for just one hour in a day and no more. More so than "moderation", it enhances my appreciation without causing me to lose sight of the real world outside of the fantasy realm. Homo sapien sapiens, in contrast to our other Homo-genus relatives, are particularly imaginative. That imagination needs to be stimulated by other imaginations on occasion, but not too much.
https://www.cdc.gov/obesity/adult/causes.html#:~:text=People...
Compared to what? To merely overweight people, to normal BMI range of 18-25, or to optimal BMI range of 20-22?
Consider if everyone was obese, with your calculation you would say the number of years lost is zero.