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Comment by bri3d | Hacker News Reader

To many, the point of "a calorie is a calorie" is not that you can't get free energy from nowhere, it's that that diet / food selection is meaningless as food containing one calorie of potential will always evolve to one calorie's worth of metabolic energy through some metabolic process or another - as in the abstract, that two "isocaloric" diets will always produce the same results. The idea of the paper is to dispel this notion.

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This smells like a straw man. From the article:

> it is important to understand exactly what it is meant by "a calorie is a calorie." The most common meaning is that is it impossible for two isocaloric diets to lead to different weight loss.

I think that is hyperbolic - I've never heard that all isocaloric diets are guaranteed to result in the exact same weightloss. The point of "a calorie is a calorie" is that you need to reduce calories to lose weight.

From the chart in the article, going from a 10% carb diet to a 50% carb diet (which is a huge change) only results in a effective caloric difference of ~130. It is _much_ simpler and more effective to just skip a 100 cal snack than it is to cut all carbs out of your diet.

According to math yes. Reality is carbs increase hunger making dieting harder.

That's just in your head not something that is universally true for everyone.

In my experience all large quantities of food increase hunger because you get your body used it. With carbs it's just easier to eat more in a smaller amount of space.

I lost weight on a high carb diet and I have lost weight on a low carb diet. Day 2 they felt different, but by day 200 the body adjusts and you get hungry either way.

To simplify the body approximates the food in your diet, but also measures the amount of fat you have. A great many things trick the first, but the second doesn’t care what or when you eat. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6039924/

This is a common motte & bailey argument. If you press in on "are all foods really the same?", you get "Oh, no, of course there are differences", but as soon as you're not pressing we end up right back at "you just have to cut your calories because all calories are exactly the same and it doesn't matter where they come from".

Ironically, you demonstrate this in your last paragraph. If all calories are the same, yeah, just cut 100 out some other way. But if they have different effects on hormones, satiety, any number of other systems, then it may not be "simpler and more effective" to "just" drop 100 calories as a snack. You may need to actually change what you eat.

A more recent study [1] showed it to be around 209-278 calories per day, and 308-478 calories per day in people who had high insulin secretion. The study also showed that a hormone that increases hunger decreased significantly on the low carbohydrate diet.

I'm currently on a lazy keto diet and am down 33 pounds. I know it's only one data point, but it definitely seems easier than other diets I've tried.

[1] https://www.hsph.harvard.edu/nutritionsource/2018/11/27/effe...

Yes, this is the argument that Gary Taubes (and others) have been making for at least 15 years: "calories in, calories out" fails not because it is wrong, but because it is not powerful enough to account for empirical observations of human metabolism. The most glaring example of which is insulin resistance from high sugar diets, which causes the body to constantly stash away calories into fat cells.

The article is saying that weight loss can happen without reducing calories, and no weight loss can occur while reducing calorie. Skipping the 100 call snack is not equivalent

One thing I've recently been thinking a lot about is how much of those calories the bacteria in your stomach may or may not use and how that translates for different people and how the chemistry in your guts can use said energy.

The real argument against sugar (or dietary advice that treats sugar just like any other calorie) is not that "calories in, calories out" is severely flawed but rather that the body is not a static heat engine (duh) and in fact changes its own metabolic optimization in response to the kind of food we eat. High sugar diets can lead to chronically elevated insulin levels, which (basically) causes the body to lock too much energy away in fat cells, leading to increased sensations of hunger for the same caloric intake.

You would be surprised how many otherwise serious people have advanced to me the notion that you can get more than a calorie from a calorie of food, mostly in service of the notion that weight loss is impossible and you shouldn't try.

> it's that that diet / food selection is meaningless as food containing one calorie of potential will always evolve to one calorie's worth of metabolic energy through some metabolic process or another

Maybe that's true evolutionarily over tens of millions of years, but it's definitely not true that cellulose calories are remotely equivalent to fat calories -- not unless you're already a ruminant, anyway. Similar issues may present themselves with other types of calories. Just because in theory we could evolve to optimally use all potential sources of energy in food doesn't mean that we actually have yet.

Also I believe there is some types of fats that aren't as easily digested. Might be some too that are not at all.

Whole system is rather complicated process and don't exactly simplify to equalling same energy you get from burning or is stored in chemical bonds...

The point of the article is that this is not true.

Chemically, a calorie is a calorie. But one calorie of fat is metabolically different from the equivalent caloric value of protein, because food is not processed by the body the same way that a calorie is measured.

It doesn't matter. If I eat nothing but 500 calories of Twinkies/cake/pure sugar (as measured on the label) every single day, I guarantee I will lose weight.

Literally no amount of hand wringing will change that fact

This is a strawman rebuttal. That's not remotely what the person you're replying to said.

The debate around "A calorie is a calorie" relates to the whole "calories in vs calories out" concept for weight loss/gain.

Examples like yours focus heavily on the "calories in", but forget to consider the "calories out" aspect. What I mean there is, when someone says that the body processes different macronutriets differently, a lot of that has to do with how it affects "calories out"

If you eat 500 calories of a food that your body will only process a small amount of, and expel the other 450 calories as waste, that 450 is part of the "calories out". That's only a net "calories in" of 50.

On the other hand, if you eat 500 calories of a food that your body chooses to process/store most of, that's 400 calories in, and only 100 calories out.

The calories out part of the equation isn't just the energy you expend per day through movement/metabolic processes/etc, it's also the calories that are expelled as waste because the body didn't store that macronutrient.

> If you eat 500 calories of a food that your body will only process a small amount of, and expel the other 450 calories as waste

Does this much lack of absorption ever actually happen, though, outside of exceptional cases like if you get food poisoning?

I used an exaggerated ratio to drive the point home. To clarify, I'm not talking as much about absorption, more-so about things like how a macronutrient affects insulin sensitivity.

Carbohydrates decrease insulin sensitivity more than protein and unsaturated fats would. Decreased insulin sensitivity means increased insulin resistance.

"Having insulin resistance means that the walls of the cells within the body that need to take in glucose for energy, have a much-lowered sensitivity to insulin. This makes it harder for the cells to receive the necessary glucose through the cell wall.

That glucose then remains in the bloodstream, resulting in high blood sugar levels, which the liver then has to manage. When this excess sugar reaches the liver, it is converted to fat. The fat cells leave the liver via the bloodstream and cause weight gain. If left unmanaged this can lead to obesity."

It is shocking to me how few people are aware of this. I read Good Calories, Bad Calories almost 15 years ago and the idea that macronutrients have a meta-metabolic effect (i.e. on insulin sensitivity) now seems so trivially obvious that you wonder how it was ignored for so long. And yet people are still repeating the CICO mantra as though we are still in the dark ages.

But the amount matters in your exaggerated ratio and far less in real life. Can you share a source on how much is actually burned with some foods? Because if you're burning 30 calories digesting a 1000 calorie meal, then just eating 2 less fries with your Big Mac meal will be a better use of your time.

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