A study suggests eating later in the day can directly impact our biological weight regulation in three key ways: through the number of calories that we burn; our hunger levels; and the way our bodies store fat.
With obesity now affecting hundreds of millions of people worldwide, this is a valuable insight into how the risk of becoming obese could be lowered in a relatively simple way – just by eating our meals a few hours earlier.
Earlier studies had already identified a link between the timing of meals and weight gain, but here the researchers wanted to look at that link more closely, as well as teasing out the biological reasons behind it.
“We wanted to test the mechanisms that may explain why late eating increases obesity risk,” said neuroscientist Frank Scheer, from Brigham and Women’s Hospital in Boston in 2022 when the study was published.
I really don’t understand what’s going on in this thread. Like… We know how sugars and fats are turned into energy that your body can use. It’s not the full story, but as an example, look at the formula for aerobic respiration, which reacts glucose (C6H12O6) and oxygen (O2) to produce carbon dioxide (CO2), water (H2O), and energy…
C6H12O6 + 6 O2 —> 6 CO2 + 6 H2O + energy
At the start you only have 6 carbon atoms (all in the glucose) and at the end they all end up in CO2 molecules, which you will exhale. Fats are organic molecules made up primarily of carbons and hydrogens… If you consume 2000 calories worth of glucose and burn it all, you have no carbons left to make additional fat. Burning fat is more complicated than glucose, but the ultimate result is the same… The carbons get bound into CO2 and you exhale them. You cannot make fat from nothing, if you get rid of more carbons than you consume you’re eventually going to “lose weight” (or maybe “lose fat” would be more accurate… eventually you’ll have to use the carbons in your fats to make the CO2 that you exhale. You could still potentially gain weight if you had more water in your body, though).
I think what people are trying to get at is that telling people to count calories and that “calories in < calories out” isn’t always helpful advice for people who want to lose weight. That’s very fair. There’s a number of factors that make it incredibly hard to lose weight. I think a huge problem with “calories in < calories out” is just that “calories” aren’t as meaningful as you’d hope in every day life. It’s very hard to know exactly how many calories you actually absorb when you eat different kinds of foods, and how many calories you absorb may depend on other factors like the time of day, what other stuff you’ve eaten, etc… And it’s also pretty much impossible for somebody to know how many calories they actually burn during a day (you don’t know what your base metabolic rate is, and fitness trackers are notoriously inaccurate). If you’re trying to have a 100 calorie deficit per day or something, you don’t actually have a lot of margin for error. That plus all of the discomfort and misery associated with losing weight makes it a difficult task, so I totally agree that it’s insensitive to tell somebody to “just do calories in < calories out” when dieting… But physically speaking that is what’s happening in every case when somebody loses fat through diet and/or exercise.
Oh, I get your point, and it makes sense. Thank you for elaborating, sir!
I do not question the study or its content or you; I question the statement the gentleman made before that a “calorie is not a calorie, and that’s what people don’t get”.
My point/my opinion was that saying “a calorie is not a calorie and that’s what people don’t understand” is wrong.
In my opinion, a calorie is always a calorie. A food does not change its calorie value based on when you eat it. What people don’t understand is how their body “uses” these calories. But this does not change the calorie content of the food; it just changes how you absorb them. It’s not that people don’t understand calories; it’s that they don’t understand the reaction that happens when the “calories” are ingested.
A pancake will always have x amount of calories, no matter if you eat it now, throw it away, or eat it at midnight or as breakfast; it will be x amount of calories. But depending on your body and in which state it is, it will absorb not all or it will absorb differently. The pancake and its calorie contents exist outside of your body and how you absorb/use them; it’s not the “changing part” of the equation.
Here is how I define a calorie, which is a fixed value:
A unit of energy equivalent to the heat energy needed to raise the temperature of 1 gram of water by 1 °C (now often defined as equal to 4.1868 joules).
A unit of energy, often used to express the nutritional value of foods, equivalent to the heat energy needed to raise the temperature of 1 kilogram of water by 1 °C, and equal to one thousand small calories; a kilocalorie.
If you want to claim that a calorie is not a calorie, I say word it differently since this is not true. A calorie is just a fixed value. You mean people don’t understand what happens after ingesting.
My point was never that calorie counting is all you need; my point was dismissing it outright is wrong, since it still tells a story, not the whole story, but certainly a part of it.
Does this make sense?
TLDR: I agree with the sentiment that a calorie is not just a calorie and understand what is meant by that. However, my issue is that it is a bit misspoken since calories are determined before you ingest/digest/absorb/pass them through. It is an expression of the energy content of a food/object, not of what you effectively get out of it when you eat it. My whole point is not to disagree with the sentiment but how it is communicated. Maybe people just don’t generally know what a calorie actually means or how it relates to our metabolism.
Yeah, we’re actually both in complete agreement. I’m just getting shit in this thread too for saying a calorie is a calorie too :P. So, I feel like I’m going insane because of this dude who’s super mad and all of the downvotes for what seem like completely reasonable statements to me, and nobody is actually explaining where I’m wrong… I think weight loss is just a pretty emotionally charged topic.
In some sense I think there are two meanings of calorie to people. There’s the actual physical energy definition, and there’s the slightly more informal usage of “how much food I consumed” and while ultimately they’re both supposed to be measures of the same thing they’re not really the same because like… I dunno, if you chug a gallon of mineral oil or something and all of your food goes through you undigested (I don’t know if that would work, but it feels like it would haha), you’re not actually going to absorb those calories. This shouldn’t make a difference for what a calorie actually is, but I guess it changes what it means in practice for people? Like if a pancake and a pineapple have the same amount of calories when you burn them in a bomb calorimeter, but you only absorb 80% of the pineapple’s calories as opposed to 100% of the pancakes due to indigestible fibre or whatever, that calorie measurement isn’t actually useful to people. But fundamentally, in the physics sense of everything, if you burn a calorie you actually absorb… it’s gone and you don’t have anything left to store as fat to gain weight. What time you consume calories won’t change this (maybe it changes your metabolism or something and you ultimately burn fewer calories, but if you actually burn all of the calories you actually absorb… I don’t understand how you could gain fat. The carbon is gone).
Haha, same - yes, I think you are right - I think we come from the perspective that a calorie is what the definition says it is, which is an energy unit. And this makes the saying “a calorie is not a calorie” sound wrong. Yeah, seems like it’s an emotional trigger for some, which is understandable.
I don’t get why this is such a problem to point out that maybe they themselves use the word calorie in a different context than it was actually intended to be used. And this does not help the confusion surrounding the topic.
The problem, I think, is that a calorie is used to describe the energy content of something and not for anything else. It is useful for food since the inherent value of energy that we need to transform every day to survive can also be expressed in calories (and so can be almost anything), which makes it easy to eyeball how much energy we can “absorb/transform” from a given product. But this does not describe how healthy or nutritious or anything else the product is or how your body is going to deal with it; it just describes the energy content of the thing.
A calorie is a measurement of energy and nothing else.
And I am sure you are right; at the end of the day, you can boil it down to one number that’s either negative, 0, or positive, i.e., your calorie deficit. If it’s negative, you used more energy than you took in, so you will need to take that energy from somewhere, which will result in some form of burning of fat or other tissues to transform the stored energy into something we can use actively, which then means you will lose weight over time. Energy can’t be created, at least not to my limited knowledge, only transformed. Of course, given that your body works within the normal human norms.
Anyway, thanks for the nice interaction. 😄
I wish you all the best this year! Have a great life!