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How do food manufacturers calculate the calorie count of packaged foods? (2003) (scientificamerican.com)
214 points by matan_a on May 29, 2016 | hide | past | web | favorite | 150 comments



The obvious next question then is how the protein and carbohydrate content is measured. That sounds like it would require more difficult analytical methods than bomb calorimetry and might not be worth the time and expense if it were not for the fact that those need to be reported separately on the label anyway.

Brief searching suggests that proteins are measured with a nitrogen content test and fats are determined by mixing the food with a non-polar solvent to see how much dissolves. Carbohydrates seem trickier and I haven't found a great explanation. Water solubility might work once the other components are removed.


The protein test was famously faked with melamine in the Chinese dog-food scandal that killed dogs and resulted in a recall:

https://en.wikipedia.org/wiki/2007_pet_food_recalls


I was following that case closely back in 2007 because of my pet (thankfully not affected). An astonishing thing I learned was that practically every brand of cat food and dog food in North America is/was manufactured by a single company called Menu Foods in Streetsville, Ontario, Canada.

The pet food "brands" don't have their own factories. They all contract it out to the same place. A few journalists remarked on this secret fact that came out because of the recall.

We agonize over which brand is healthier for our cats and dogs, but it's all an illusion. The majority of US and Canadian pet food is made at one factory with the same basic animal ingredients, same quality control, same employees, and the same machines. Maybe they adjust the proportions slightly and tweak the flavors. Then they slap on different labels like Purina, Iams, Royal Canin, whatever.

It's saddening to learn that we really don't have as much choice as we think. I'm much more skeptical and questioning than the average person, and yet I assumed that the pet food's "brand name" somehow made a difference.


I am a veterinarian with an interest in nutrition. While it is true that the vast majority of the brands are virtual brands who have another manufacturer making their food, it is not true for the three brands you have mentioned whose owners sell most of the food sold. Purina (Nestle), Iams (Mars) and Royal Canin (Mars) manufacture their own food, as does Hill's (Colgate-Palmolive) and Pedigree (Mars). Mars, Nestle and Colgate-Palmolive represent over 80% of the market share in pet food. [1]

[1] http://www.slideshare.net/Euromonitor/state-of-the-pet-care-...


<Purina (Nestle), Iams (Mars) and Royal Canin (Mars) manufacture their own food>

One roster:

http://aplusflintriverranch.com/define-menufoods-petfoodreca...


Ok, I was unaware of these SKUs. I will have to ask if they learned their lesson.


> We agonize over which brand is healthier for our cats and dogs, but it's all an illusion.

The fact that one factory makes the food doesn't mean brands are illusion. One factory can make different kinds of food. True, machines and employees are the same, but that does not mean food content is the same - in fact, different companies may very well order very different mixes to be packed on the same equipment.

In fact, the same factory produced Chevrolet Prizm and Toyota Tacoma - but they are hardly the same car.


Out curiosity, is (relatively) unprocessed meat for pets available in supermarkets in north america?

In Australia you can buy packets of kangaroo meat for consumption by pets as kangaroos are essentially pests in many areas. This results in a large supply of meat that has limited commercial value so most supermarkets will stock frozen packets of what is (I believe) 100% kangaroo mince for people to feed to their pets.

Curious if there is an equivalent option elsewhere.


This is the most unique and fun thing Ive seen shared on HN in a while! It makes a ton of sense. I can speak for all of North America, but nothing like that is available in Ontario (the most populous province in Canada). We have dry food and canned meat for dogs and cats, and a new thing showing up in grocery stores in Canada, and walmarts in the US are refrigerated, 'fresh' meat pellets. They are expensive, and spoil quicker than my cat can eat it. I would jump at the chance to have 100% pure shredded meat for my pets. I bet there are lots of happy dogs and cats in AU that dont even know how good they have it :)


>> The majority of US and Canadian pet food is made at one factory

This is true if you're talking about wet pet food - there are other makers of wet pet food and dry pet food (which is over half the market) is made by other companies. Mars/Nestle (the same people who make candy...)


> We agonize over which brand is healthier for our cats and dogs, but it's all an illusion.

Does manufacturing the product at the same location imply that the content is the same?


the majority of pet food is meat not fit for human consumption. [1]

if you aren't feeding your pet meat that you eat, it's living on extreme crap.

[1]: http://www.dogfoodadvisor.com/dog-food-industry-exposed/unfi...


My dog will eat other animal feces. His standards for "food" are pretty low.


No one is talking about standards. I'm talking about food that might make your dog sick or malnourished.

But to each his own.


Lulz

Apparently this trait evolved as a way to keep the nest clean and safe during nursing of pups.


People like fancy food. That doesn't make non-fancy food extreme crap.


"not fit for human consumption" is not a synonym for "unfancy". It describes the processes involved to arrive at the final food. Filet mignon can be unfit for human consumption, while pigs' feet can be processed correctly and be fit for consumption.


Check this out: http://www.alive.com/health/fit-for-human-consumption/

Animals that are sick or unhealthy are separated from the herd and slaughtered independently, then sold for pet food and livestock feed. This was partly what fostered the mad cow issue.

There is higher risk for illness with non-human grade food. If you don't want higher risk for your pet than child, you shouldn't feed the off-the-shelf non-human grade food.


> if you care about your pet like you do your child, you shouldn't feed the off-the-shelf non-human grade food.

This is... an interesting generational thing, I think. To most older people, the idea of caring as much for your pet as you would for a child seems viscerally wrong. They even economize on pet healthcare. but... among those younger than me, your view, as far as I can tell, seems to be the norm. The very idea that you might be unwilling to go bankrupt paying for medical care for your pets seems abhorrent.


Great point, I have definitely noticed this in my own family. The elders are not only against "wasting" money above the minimum required for sustenance, but they get openly and visibly angry about it when someone else does. For some reason, this particular issue crosses over from "well I wouldn't do it, but to each his own", to seeing it as a fundamentally immoral act. It surprised me in the beginning.

Personally I can't understand the logic. Who cares what species something is, it's just a question of level of consciousness. A dog is pretty much a 2 yr old child. Why have no concern for such a consciousness, whether it's an animal, android, human, or whatever.


>A dog is pretty much a 2 yr old child.

So is a pig, so this logic really only applies to vegetarians. There is still something else that motivates meat eating people to care more for their pets.


> So is a pig, so this logic really only applies to vegetarians.

The quality of life of farm animals should also be respected. If they live their lives in suffering, that shouldn't be taken lightly.

At the same time all animals will die at some point, with or without human intervention. If that death happens at a slightly different time for the reality of the way nature works, that's not inconsistent.

Keep in mind that wild animals don't generally die of old age gracefully on a golf course. More often than not they're ripped apart by some other animal, or starve to death from injury, or are consumed by disease, etc. Death by human hands is probably one of the less cruel fates.

A free-range animal on a cruelty-free farm (if that really exists), with the benefits of human medicine, and a precisely implemented death, is probably one of the happier existences an animal can have.


>that's not inconsistent

Only if you put down any pet immediately when it becomes sick with something non trivial (what we do with farm animals). However, that's not the case when people spend thousands on a pet to keep it alive with complex treatments.


It's pretty clear that the mental abilities or atributes of the animal is not the primary differentiation between 'something like family' and 'something like food.' The differentiation is in the emotional attachment a person has to other animals that belong to the same class as the animal in question.

I mean, I'm not saying this is right or wrong, just that this is how most people see the matter.


To provide the devil's advocate position, why does mere ownership suddenly imply a much higher duty of care? It would be morally abhorrent if we started euthanizing millions of toddlers who we couldn't find homes for yet we're fine doing the same to pets. What, morally, should be the difference between "pets we can find a home for" and "pets we can't find a home for"?


I think most people would be more repulsed if a child's own parents mis-treated them, rather than if an orphanage did. The whole scale is just shifted up for humans. Bias towards "ownership" still exists.


> This is... an interesting generational thing, I think.

Totally. Not too long ago, pets, and livestock, would be fed table scraps and glad of it.

Like we've been taught - actually shamed - into using soap, deodorant and sundry other 'essentials' to the soap manufacturers well-being, so with pet care.

Curious about what else they'll come up with next to mop up wealth and productivity. It's bound to be amusing.


Are we talking human grade table scraps? :)


Are dogs able to safely digest some foods that humans aren't? I mean, does it really need to be pointed out that dogs have different nutritional and hygiene requirements than human children?


> does it really need to be pointed out that dogs have different nutritional and hygiene requirements than human children

The most common dangers are onions (or things cooked in onions) and chocolate. They contain chemicals that are toxic to dogs and should always be avoided.

Similarly, many humans are allergic to many foods, and not every human can eat all "human-grade" food.

"human-grade" is only a measure of risk of unexpected contents (disease) in the food - not a recommendation that all humans should always eat it.


I was going to say. A number of friends have had their dog chow down on a rotten deer corpse to no ill effect.


The linked-to https://en.wikipedia.org/wiki/2008_Chinese_milk_scandal was way more scandalous.

When bought in bulk, milk isn’t priced by the liter because it is too easy to water it down. Instead, it is priced by kilograms of protein.

Measuring protein is hard, so they measure nitrogen instead (https://en.wikipedia.org/wiki/Kjeldahl_method#Conversion_fac..., https://en.wikipedia.org/wiki/Dumas_method#Advantages_and_li...). Melamine (https://en.wikipedia.org/wiki/Melamine) is cheap, rich in nitrogen, and, unfortunately, poisonous.


This scandal is the reason Dutch supermarkets still limit the amount of baby formula that can be bought per customer, so many Chinese trying to buy up large amounts that there was a risk many stores would run out.


Hong Kong even restricts export of baby formula (and smugglers are regularly arrested on the border to mainland).


I always wonder why they don't just order more from the factory and sell to the Chinese? (Or raise prices.)

Why don't they want to make more money?


From what I know, it is because of export control and regulation.

Nutricia, the Dutch milk powder company, cannot easily sell Dutch milk powder to China because import/export regulations don't easily allow them to do so. So they opened a store in China. But because of Chinese food regulations they cannot use the original formula. But consumers distrust the Chinese store because the formula has been altered. So people keep buying "real" Dutch milk powder fron smugglers.


I don't know if the factories are manufacturing enough, or capable of ramping up to do so. It's a huge increase in demand. I heard of similar problems in Australia.


Sure, but why not just charge more and sell to the highest bidders?


Because it's baby formula, produced here, and rather vital. Government is _not_ going to stand idly by if it disappears from stores because some other country bids more.


It's called "civilisation"


Civilization is to deny milk powder to people who want to pay for it, just because they are from another side of a border?


They went hard on the justice atleast:

"Two people were executed, one given a suspended death penalty, three people receiving life imprisonment, two receiving 15-year jail terms,and seven local government officials, as well as the Director of the Administration of Quality Supervision, Inspection and Quarantine (AQSIQ), being fired or forced to resign"


Stupidly enough, that scandal was partially to blame on the government price caps on milk.

Farmers' inputs were getting more expensive but they were prevented from raising prices. So some farmers were more likely to resort to such poisonous fraud.

Of course, the foreign milk products they import these days are even more expensive.


The same cheat was used in milk in China in '08. Baby formula was effected and babies died. Many companies were doing it and something like 50,000 babies were hospitalised. https://en.m.wikipedia.org/wiki/2008_Chinese_milk_scandal


Considering how cheap protein is, you must be the greediest person ever to fake baby formula.


Also this is interesting... https://en.wikipedia.org/wiki/Gutter_oil


The Chinese government capped prices of milk products in a bid to tame inflation.


Are these Chinese companies getting rich, or just getting by? Quality food is expense.


Isn't the simpler & more plausible explanation that most individual foods aren't measured like that, but rather just by summing up the protein/carbohydrate/fat etc. amounts that go into making the food?

E.g. if you're making frozen pizza just add up flour, the pepperoni etc. you put in and divide it by portion size.


Pizza in particular is an interesting example because I would expect leavened bread products to be one of the cases where summing the components would cause more problems than usual (because you're going to lose sugar and other nutrients to the yeast). I'm not sure how many calories worth of carbs yeast consume during normal bread making, but I would expect it to be measurable. When making wine, yeast can easily consume pounds of sugar within days.


I suspect it's not a large effect for bread. My family bakes our own bread, and I would say without having measured it on a scale, that there's not a noticeable loss of weight from one end of the process to the other. Also, you'd notice the stuff bubbling if there were a significant production of CO2.

I've also made beer, and it bubbles like crazy once it gets working. One possible difference is that bread is made from (mostly) starch, whereas beermaking converts starches to sugars before fermentation, and the yeasts can work more efficiently on sugars.

Of course you can also load up commercial pizza with sugar... one of the reasons why we make our own pizza.


If anyone can find a reference on the amount of CO2 produced during bread making it would be easy enough to calculate. I haven't been able to find any relevant sources except this old one [1] which mentions that the alcohol content in bread can be as high as 1.9 percent (which sounds quite high to me, but it's hard to critique when they don't explain their methodology).

[1] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1709087/?page=1


Well, all I can offer is... tonight is baking night. I will weigh the ingredients, equipment, the risen dough, and the final product.


How do you distinguish between evaporated water and respirated CO2?

As an aside: My understanding was that most breads don't vent all that much CO2. Bread doughs are not risen in processes that leave the opportunity for rapid bubble formation and dissolution; If they did, baking after that first rise would give you a layer of thick dense bread, and another layer of fluffy bubble-bread on top.


You could also seal the dough in a large bag, and measure the volume of gas produced.


Won't the yeast get less oxygen that way?


So far...

Flour 765 g, some white and some whole wheat

Yeast 18 g, probably too much

Water 611 g, eyeballed 600 ml in old glass measuring cup

After kneading 1408 g

After first rising 1416 g

After "punch down" and second rising 1406 g

Formed into loaves, waiting to rise before putting in oven

Edit: After baking, 1271 g

I'm using a creaky old Ohaus dual pan balance, surplus from an industrial lab. The process is not entirely "quantitative" in chemistry terms because there are some minor gains and losses. I have to flour the kneading cloth to prevent sticking, some dough may get lost on my bowl, and so forth.


Presumably that gain after first rising is experimental error? What could cause it to gain weight there?


Probably experimental error.


CO2 is but one of the products of the metabolism via oxygen. Water is another one.

The CO2 escapes, taking C out of the bread. The water (mostly) stays, adding extra O2 into the bread. I don't know which process has the bigger impact on weight of the dough, though. Especially as the dough also dries out over time.

Probably not very much impact, as you say.


Couldn't things like yeast be handled by some standard pre-computed approximate lookups?


Definitely. You might not even have to consider baking time or temperature to get a good enough number to cover the calorie difference from lost carbohydrates and produced ethanol to meet the level of accuracy required for food labels.

I only brought it up in the first place because whenever a simple solution to a complicated problem is put forward, it will inevitably turn out that it's either not general enough or special cases need to be handled to keep it simple. There's nothing wrong with needing special cases, but it's always nicer to figure out what the special cases will be before someone does a bunch of architectural work that hasn't considered them.


I know some smaller brands estimate using the USDA Food Composition Database (https://ndb.nal.usda.gov/), which in turn gets its data under the National Food and Nutrient Analysis Program (http://www.ars.usda.gov/News/docs.htm?docid=9446).

This is what I could find about their data:

"Data have been compiled from published and unpublished sources. Published data sources include the scientific literature. Unpublished data include those obtained from the food industry, other government agencies, and research conducted under contracts initiated by USDA’s Agricultural Research Service (ARS)." (http://www.ars.usda.gov/sp2UserFiles/Place/80400525/Data/SR/... <- page 2)


I found this URL that explains different methods of carbohydrate analysis in food: http://people.umass.edu/~mcclemen/581Carbohydrates.html


> 9 Kcal/g for fat. [...] These numbers were originally determined by burning

This method for calculating the calorie count for fat has in my opinion allowed the demonisation of fat.

Our stomachs are imperfect at digesting globules of fat. Burning-until-gone releases much more of the energy than surface acting acids and proteinases.

Effective calorie count for fat just has to be so much lower than the listed value.

Constrast that with sugars, where the absorbtion mechanism is crystaline dissolution. Disolving crystals is an almost perfect 1-1 process


Agreed. 500 calories from chicken or a lean protein like crab is very different from 500 calories from a pastry. What should be highlighted is amount of sugar and carbohydrates, not total calories. Not every calorie is created equally. In fact, you could almost remove carbohydrates from your diet and be unaffected, but the same isn't true of protein and good fats.


It is of course different. Carbohydrates, protein and fat all undergo different metabolic pathways. Further down you are wondering why you might not have a high karma on this post. I think it's because what you have written conflates 2 issues (I suspect, though, that you aren't actually conflating them... just your writing is unclear).

500 calories from whatever source is 500 calories, when we are talking about energy. It is definitely possible for people to excrete excess calories, but if for example you are excreting a lot of fat, you will know about it. It is not pleasant. There are a fair number of people who are unfortunately misinformed and think that somehow they have super digestion for carbohydrates for example. They think they can extract 1000 calories from 500 calories of carbohydrates. This is impossible and it's why it's important to understand that from that standpoint a calorie is a calorie.

Of course nutritionally they are very different things. They are digested differently, at different speeds and metabolically burned in completely different ways. Different foods also have different nutrients and it is important to make sure that you get these nutrients. You can go an awfully long time without any symptoms being malnourished only to eventually come to a very serious problem.

So many people are (for lack of a better word) arrogant in their beliefs about nutrition. However, we still know very little about how our body works. Traditional diets have a long track history with many, many people. We have a good idea about potential nutritional problems and how to counteract them.

I was vegan for many years (although, strangely, not ethically vegan -- I just enjoy eating that kind of food). I have seen many invented diets cause serious problems and eventually I spent considerable effort to learn about traditional vegan diets. I'll caution you that the current attitude of "You can just cut out carbohydrates from your diet and be healthier" is unlikely to be true. Nutrition is complicated and can't be boiled down to something so simple. There are many shapes of diets that can be healthy but seemingly insignificant changes can take their toll on your long term health. Please exercise caution.


> I'll caution you that the current attitude of "You can just cut out carbohydrates from your diet and be healthier" is unlikely to be true.

I have a lot of sympathy for your conservative and skeptical stance in general.

I am glad though, that a lot of people have done the self-experimenting (that we probably wouldn't do to normal experimental subjects) and gone on a low carb diet.

They seem fine.

There are also some better monitored people on a low carb diet, eg for some kids with epilepsy it's the only thing that works. The kids main problem is usually getting enough calories, but not any lack of other nutrients. (I think the go to source of extra calories is coconut oil, because the kids seem to mind that the least.)

See eg http://www.nytimes.com/2010/11/21/magazine/21Epilepsy-t.html...

Edit: just checked the article above. Looks like they need to add multivitamins etc. Poor kid: his diet needs to be much more extreme than eg Atkins diet to keep the epilepsy at bay.


We've evolved as omnivores with unfussy requirements and highly efficient metabolism


Mikekchar, "500 calories is 500 calories" is a tautology and neither a clever writing device nor a serious argument.

I've cut carbs out of my diet a few months ago, after I chewed through the 200-pound mark. I noticed I had trouble running, walking and even standing. I dropped bread, pasta and refined sugar, though I still eat fruits without restriction.

The result is that I've been steadily losing weight and shedding fat, primarily the nasty layers found in the pubic area.

My research has thoroughly convinced me that carbless diet makes the body burn fat and serves as a protective factor against neurodegenerative diseases.


I'm glad you are losing weight (if that's what you are trying to do). However, when you change your diet comprehensively it is easy to overlook changes. For example, did you seriously measure your caloric intake before and after you changed your diet? Are you sure that you did not overlook sources of calories?

I helped a friend of mine lose weight once. His original diet consisted of a single muffin and coffee for breakfast, a subway sandwich with iced tea and one of those tiny bags of potato chips that come with the meal, and for dinner some salad and spaghetti or something. It sounds reasonable, but for the life of him he couldn't get under 220 lbs.

We went through the numbers. The muffin he was eating was 500 calories! The chips, 150 calories. The salad dressing he was eating on his salad was over 100 calories. The ice tea was 180 calories. So that's 930 calories, or nearly 1/2 of his daily requirements in just those 4 items of food.

We made a few minor substitutions to his diet (which actually increased the volume of food he was eating) and he started running 2 miles a day with me at lunch (which is worth about 200 calories a day). He was down to 160 pounds in no time. Our biggest problem was trying to make sure he didn't lose more than 2 lbs a week because that can be hard on your liver.

The thing is, if he had gone on a no carb diet and found alternatives in his diet he probably would have had the same result. No muffin. No potato chips. No ice tea. Probably substitute the salad for something with more protein.

Like I said, I'm happy if its working for you. I know a lot of people on low carb diets. Every single one of them is overweight. I have yet to meet even a single person in real life for who this strategy has worked. Mostly I see people change their diet, lose some weight when they eat more healthily and then gain it back when they mistakenly think that as long as they keep out the dreaded carbs, then they can eat whatever the heck they like without consequences.


i don't understand why your comment scores so low. It's pretty clear that our bodies will absorb 500 sugar/carbohydrate calories much more quickly than 500 protein/fat calories. You will get a much greater insulin response when eating a pastry than a chicken breast.


I suspect I'm being down voted because I said I don't believe carbohydrates are required for survival.

While glucose is essential for life since the brain cells die quickly without it, glucose does not have to be obtained from carbohydrates. It can be obtained from protein or fat by breaking down the protein or fat into glucose. In fact, a good percentage of protein (~50%) becomes glucose when it enters the body.

Protein is favored over many other energy forms since it contains amino acids, one of the most useful sources of nutrients to your body. Your body cannot store amino acids and yet it needs a daily intake of amino acids to survive. Additionally, protein conversion to fats is costly, so your body under normal conditions does not usually convert much of it, compared to fats and carbohydrates (carbs almost immediately undergo storage). Good fats, however, are beneficial (essential even for health) than carbohydrates in all cases.

Or perhaps someone might enlighten me why I'm wrong (at the time of this writing, my original comment has 0 points of karma).

I've cut bread and processed sugar to a large degree from my diet and stick to lean proteins like seafood and chicken, and have found myself to be quite lean and healthy (bulking even with my anterior/posterior chain, triceps/biceps). I haven't counted calories since I switched to a diet that focuses on lean protein and seafood (and I suspect there are days where I eat more than 2000 kCal).


<While glucose is essential for life since the brain cells die quickly without it>

Not true at all. The brain runs just fine on ketone bodies in the absence of dietary glucose.

The few organs that do require glucose are supplied by protein conversion (gluconeogenesis).


I can't add anything constructive to your glucose conclusions, though I can say that eating 2 medium chicken drumsticks with skin has made me satiated to a degree I never thought possible.

I too experienced a certain effortless growth of muscle mass after eating enough protein for my daily needs, too.


It's a function of diet and exercise. "Absorb" also begs the question "for what?" Your body can absorb protein and repurpose it into other proteins for muscles or whatnot, but turning that protein into energy is harder.

It's like saying that a city can absorb a terajoule of gasoline more easily than a terajoule of coal or a terajoule of lithium batteries. It's true, but "which is absorbed faster?" is a vast oversimplification of a more complicated question, which is "how much is needed?"

To extend the analogy further, if a city had mostly electric cars and a coal power plant, it would have no trouble absorbing the lithium batteries or the coal, but would have more trouble absorbing the gasoline.


It's a well understood process:

https://courses.washington.edu/conj/bess/fats/fats.html

Also, you can experience what happens when you don't digest fat by eating a good bit of Olestra.

https://en.wikipedia.org/wiki/Olestra#Side_effects


don't eat olestra


Also dont eat fish oil capsules on an empty stomach. Your Herman Miller chair will receive a present that you could not help deliver. The oil will literally leak out since there is no other digested food to keep it behind your sphinter. One of the weirdest stenches of partially digested fish oil bile that resists all attempts to nuetralize the stain and odor. I am passing on great wisdom as funny and crude as it sounds..(That chair was eventually sold at a huge discount and was probably bleached. Steelcase Worklounge is better anyhow so I'm not totally out of shape about it.)


This isn't so. Quoting [1], energy dissipated as side-effect heat during gestation and storage:

Carbohydrates: 5 to 15% of the energy consumed

Protein: 20 to 35%

Fats: at most 5 to 15%

[1] https://en.wikipedia.org/wiki/Specific_dynamic_action


> Protein: 20 to 35%

Doesn't this assume that you're starving [1]? Proteins are a last resort, and since it's somewhat toxic to convert them, they're simply not processed if it can be avoided [2].

[1] https://en.wikipedia.org/wiki/Gluconeogenesis "the process occurs during periods of fasting, starvation, low-carbohydrate diets, or intense exercise."

[2] http://antranik.org/the-catabolism-of-fats-and-proteins-for-...


Yes, looks like this. And in addition in average human this pathway is limited to 300g amino-acids -> glucose per day if I remember correctly. Still what should happen if protein intake is tripled say from 50g/day to 150g/day? Excess amino acids have to go somewhere...


This adds to my point, it does not subtract to my point.

Not only is the fat digestion process inefficient, but on top the fat absorbtion process consumes more energy to make happen ( that heat )

We'd have to see where in the large 5-15% ranges various items stand.

Sugar dissolving in water... I'd be amazed if that released 15% of the energy. I'm still amazed it would be as high as 5%, so thanks for that info

EDIT: spatular set me straight with a detailed process for sugar absorbtion


Well, fat digestion seems to be effective even comparing to hydrocarbons.

I think longer hydrocarbons including sugar have to be broken into fructose and glucose during digestion. Fructose cannot be immidiately consumed by cells, so it's converted into glucose in liver. On top of that, there are about 5g of glucose total in bloodstream at any given moment, so exess have to be accumulated by liver/muscle cells that have to store it in a long-chain hydrocarbon form (glycogen). Each conversion requires some energy, so 5-15% isn't that much...


same thing is for protein present in grass but indigestible for humans.

cows can extract "enormous" amounts of protein from foods that humans wouldn't ever.

it's very hard measuring how much digestible protein something has, such as beans, or lentils, or soybeans. it depends if you eat the shell, did you blend the shell like a mad man, even if you blended beans into a homogenous phlegm


Cows are not extracting protein from grass (well not much), they are converting the cellulose in the grass into microorganisms and then extracting the proteins from the microorganisms. The ruminant digestive system is an amazing system [1].

1. https://en.m.wikipedia.org/wiki/Ruminant


You mean, microorganisms allow better deconstruction of cellulose which then frees the protein and makes it digestable?

Yeah, ruminants are amazing with their cyclic puking and eating :)


Cows actually can't digest cellulose at all - what they can do is harbour the microorganisms that can. These microorganisms are then eaten by the cow and provide most of the protein in a cows diet.


The body is very efficient in storing fat, more than carbs or protein. But burning fat is inefficient. But this is just from the top of my head.

I think its just a lot easier to eat a lot of carbs. Fats and protein make me much more saturated more quickly.

I don't think there is some magic formula.


> burning fat is inefficient

Huh? The body is perfectly happy to burn fat. You just have to give it the right conditions. In fact, the body can get practically all its energy from fat, it's called ketosis. You can achieve a state of ketosis either through a high fat, low carb diet or fasting.


Yup. I've been doing a ketogenic diet the past 6 weeks and it's pretty awesome.


In general your body doesn't take the fat you eat and store it as fat. It takes the excess sugars and stores them as fat.


Maybe we have differing ideas of "general" but in healthy non-overeating people, the fatty acid profile in the body is reasonably close to the dietary profile. There is some conversion like elongation and desaturation of essential fatty acids and you can also find some short-chain fatty acids from fermentation in the gut, but it takes excessive amounts of carbohydrates for de novo lipogenesis. Also, what else would the body do with dietary fat other than storing? A fatty meal would quickly overwhelm the capacity of the blood if there was no mechanism to quickly dispose of dietary fat.


Storing fat? ... You know have to burn the the fat to be able to store it? The fat doesn't have some other pathway from stomach to body fat - all the 'fat' you carry has been burned to get there. So whatever you have been overeating will be the cause.


> The original method used to determine the number of kcals in a given food directly measured the energy it produced.The food was placed in a sealed container surrounded by water--an apparatus known as a bomb calorimeter. The food was completely burned and the resulting rise in water temperature was measured.

I don't think the article addresses the following point. I may be totally wrong but I suspect the residues of the combustion still contain organic molecules that could possibly be broken down furthermore by some other process and release more energy (I believe it's the case with fuel, I remember a chemistry teacher telling us that burning fuel was terribly inefficient).

Would it be possible that the digestion mechanism is somehow more efficient at breaking down this molecules and produce more energy than combustion?


Considering how nutritious(for bacteria) our faeces are, I strongly suspect not. If anything, we know that calories from certain types of food (like nuts) are not absorbed in 100%, so even though a packet of nuts might say it has 500 kcal, it doesn't mean you will get 500 kcal out of it.


Digestion is a red herring here. It's how the nutrients are turned to energy in the cells. And that's an oxidization, just like burning but more controlled.


In Poland it's regulated, you can be off by 15%. My mate did tests in a lab. All products he picked showed 15% lower kcal value on the packaging.

I pick reduced fat houmous from the fridge. The label says 100g has 256kcal (18g of fat, 13g of carbs, 8,5g of protein = 248kcal)


And apparently in the US you can be off by whatever you want

https://www.youtube.com/watch?v=hE2lna5Wxuo

The video also deals with calorie count in restaurants. The NYC regulation to require calorie counts directly on the menu really seems like a good idea. Other than the people already knowing the rough calorie count, who checks the obscure and difficult tables on the website?


who checks the obscure and difficult tables

I'm not sure exactly which tables you're referring to here, but if you mean tables showing nutritional details beyond the mere number of calories: Being able to look up how many grams of carbohydrate they're consuming is a incredibly important for type 1 diabetics.


>I'm not sure exactly which tables you're referring to here,

These

http://www.bk.com/pdfs/nutrition.pdf

nutrition information tables. The Burger King one actually looks quite reasonable. Compare this to the German Starbucks one:

http://globalassets.starbucks.com/assets/4145371584DF4F75A9E...

I doubt a lot of people would reconsider their choice to order a frappuccino if they knew it contains as much calories as a Big Mac.

It's good that it's so detailed, but a tl;dr version on the board would be good. It's not like the average joe opens this on their phone to compare how many calories each product has.

>Being able to look up how many grams of carbohydrate they're consuming is a incredibly important for type 1 diabetics.

Valid point


Huh that was really interesting. Thank you, I think I might spend some time looking up more today.


The government doesn't even have the resources to check fish species that are sold in grocery stores and restaurants [1]... food labeling is a big problem in the US.

1. http://www.npr.org/sections/thesalt/2013/02/21/172589997/one...


>And apparently in the US you can be off by whatever you want

Classic freedom


You would have to be very confident in the accuracy of your measurements to throw away your margin of error like that. If you report values 13% lower to try to appeal to consumers and your lab numbers are off by 3%, now you're wrong by over 15% and you're going to have a problem (if anyone even notices, or cares).

Are there any Polish media reports about this practice? It sounds like the kind of thing the American media would love to report about if it was happening here. (Anything that fits the basic format of "Are companies misreporting arsenic levels in your child's grape juice? Story at eleven!" is going to make a journalist here salivate.)



Would it be possible for the baker to distribute bread to customers in such a way that the weight appears to follow a fair curve for any one customer, but is still unfair if all loaves for all customers were analyzed in aggregate? (something like Simpson's paradox?)

After the professor first discovered him he obviously could have started giving him loaves calculated to follow the fair distribution, but I'm not sure if it's possible to scale that technique.


Each customer would need to see a normal distribution (possible), and each would need the mean to match the "correct" value (not possible without the overall mean matching the correct value).


A bread loaf is discrete . Use the same fractional unit rounding technique from Superman II / Office Space.


If he is able to control the loaf the professor gets he could buy 1 correct form.


There's a book with an apocryphal story about how a coin maker was a accused of cheating because his gold coins had excessive standard error, before the discovery of standard deviation.


Well who does the measurement to determine the percent error? Presumably it would be the government or some lab at the request of the government, so food manufacturers could just use that same lab.


Low fat diets are actually considered unhealthy by nutritionists now, apparently.


Depends on what side of the package you're reading.

On the back label its says calories per serving. On the front they use a different serving size to make it seem like it's low-cal.

Like popcorn that's 140 cals/serving, but on the front it says 35 cals per cup.

http://www.foodfacts.com/ci/nutritionfacts/snack-foods/smart...

Or a pkg of 2 cupcakes is 380 cals, but they'll say 190 cals per cake (in small type). It makes you think it's 190 for the pkg of cakes.


But they also list servings per package. As someone who relies on this information out of medical necessity I've never felt it to be that confusing.

The EU/UK, on the other hand, makes it incredibly difficult by listing things in units of 100g. Nothing like sitting in a dark movie theater trying to calculate fractions.


I often find it more convenient actually because often you don't eat "one serving". Consider breakfast cereals, rice or pastas. Having the per 100g values allows you to actually compare one item to the next. When I'm the US I find myself trying to convert back the per serving to per 100g to get back to known territory.


This.

Not even primarily due to health/nutritional concerns. A lot of the cereals in the US are way to sweet for my taste. Haven't found a better way to figure out which isn't other than comparing contained sugar.


The 100g listing is mandatory, but many products will have an extra column for portions where it makes sense. If they don't, you might need to pull out a calculator to figure out how much sugar is in x bits of chocolate, but it makes comparing different products much simpler.


IME foods will state values per 100g as well as values per typical serving.


The new FDA label standard would likely require the cupcakes to either treat the package as a serving or list the calories for both 1 cake and the entire package.

http://www.fda.gov/Food/GuidanceRegulation/GuidanceDocuments...


This reminded me of a question I've always had... there's always a lot of mass of the food not accounted for in the Fat/Carbohydrates/Protein/Fiber. For example, a can of food that weighs 454g net might only have 150g accounted for in the nutrition facts. What's in the rest of the food, besides water?


Probably fiber and water. When they measure fiber, they tend to measure specific types of fiber. I'm assuming there are a lot of undigestible things in food that don't fall into the neat categories.


What's funny to me is that "fiber" is just ripped up plant cell walls and interstitial material, which is virtually all carbohydrate. it's just that it doesn't all get truly digested.



usda when measuring cooked or raw beans, for example, measures them differently.

for example cooking 100g of beans in 500g of water would result in, let's say, 450g of beanwater (beans + water). usda takes 100g of that beanwater and says it's 100g of cooked beans (water content of cooked beans is way higher than in raw beans [their tables say]).

I was worried there's not enough protein in 100g of cooked beans, but there is, it's just not 100g of cooked beans, it's 450g of beanwater.


There are foods on which the standard processes don't accurately measure energy content. Or at least, certain manufacturers tell us that. Not sure if to believe them or not.

Example: Quest bars. Their syrup would typically show 4 kcal per gram, but is actually closer to 2. Supposedly. That's how a bar can have so few calories and such good macros.

Ultimately, if you're consistent with tracking your calories and its effect on your weight, it doesn't matter if the values are off by 20, 30, or 50%. Just be consistently off by... 50%.


I'm not sure what the syrup in those bars would be, but most liquid sugar products have a pretty substantial portion of water by mass.


The original syrup was https://en.wikipedia.org/wiki/Isomaltooligosaccharide . I buy retail for my own recipes, under the brand name VitaFiber.


The Gastropod Podcast just had a great episode about measuring calories:

https://gastropod.com/the-end-of-the-calorie/

"For most of us, the calorie is just a number on the back of the packet or on the display at the gym. But what is it, exactly? And how did we end up with this one unit with which to measure our food? Is a calorie the same no matter what type of food it comes from? And is one calorie for you exactly the same as one calorie for me? To find out, we visit the special rooms scientists use to measure how many calories we burn, and the labs where researchers are discovering that the calorie is broken. And we pose the question: If not the calorie, then what?"


Cooked food often have much more digestible calories than raw food. Because the heat breaks down complex molecules and make them easier to digest. This isn't reflected at all in these measurements.

This is why it's real hard to stay healthy on a raw food diet.

I learned this from this book, which I really recommend:

https://www.amazon.com/Catching-Fire-Cooking-Made-Human-eboo...


I have a related question: Can the calorie count reliably predict the effect on a persons weight? Or is the amount of carbohydrates and fats much more important?


All calories are almost equal, as long as your body is in proper condition to absorb them.

The body isn't perfect, and will never absorb 100%. You can figure how much by measuring calories left in feces (it's very little, our digestive system does a great job).

This waste will vary slightly. Heavy processed food and sugars will be close to 100% absorption, harder to digest food can be slightly lower, but still within ~10%.

The reason we recommend lowering high fat, high carbs and sugary food to people isn't because calories are different, but because it is a lot easier to consume a huge amount of calories through those.

Think about 500 calories.. That's 1l of soda, or 2 candy bars, or one Big Mac. All of those are very easy to eat/drink mindlessly. Now compare eating 1.2kg of carrot, 2.5l of vegetable soup or 500g of rice.


I think the answer is that it's really hard to study this, since food diets are hard to control over long periods of times but that current research is consistent with calorie counts being a good estimator of a person weight gain/loss. Here's a reasonable summary with some studies you can look at for the details. [1] But this is certainly an area of ongoing research and the devil is in the details: does it matter when you eat? [2] Does your gut microbiome affect it significantly? Genetics? Is there inter-person variation in how their body adapts to different food? Does fat/carbohydrates/protein/fiber content affect satiety in a manner that helps people lose weight in real life situations even if it doesn't matter in a clinically controlled setting where overeating is impossible?

We might never have full pictures of all these questions.

[1] http://examine.com/faq/what-should-i-eat-for-weight-loss/

[2] I know specifically that this is currently being tested in some large-scale, high-cost studies. Which tells me that researchers aren't as confident as [1] makes it sound like.


I won't link to any studies but regarding [2] (gut microbiome] does affect it ever so slightly. I'm just stating things from memory now, but I remember reading that our gut bacteria now is different from 50 years ago in such a way that a person eating (for example) 2000 calories then, would now have to eat 2200. Made up numbers, but the effect was between 5-20%.

As for your last question (food composition and satiety), tangentially related, in the literature regarding this it seems as if keto has a lot of support for weight loss. Not because of the way it affects your metabolism or gut bacteria, but because it does satiate people more adequately than other diets it was tested against (regular western, Scandinavian and paleo).


Reliably? Short version is no, and it is even more complicated. Two individuals eating the same food will gain weight differently, depending on a large number of factors.


Bit different answer: Yes it is possible. While it is true that two individuals eating the same food will gain weight differently, if you count your calories and measure everything you'll eventually learn (In the body building community we usually say two weeks) how many calories you need to keep your weight. With that information, you can adjust your calorie intake to lose weight. Say your maintenance is 2500 calories, then by eating 2000 instead, you'll lose 1 pound a week.

Keywords if you want to look it up more: TDEE, 1 pound = 3500 calories, calorie in calorie out


That is not entirely true (not entirely false either), the reality is more complicated.

Your metabolism level, and the percentage of calories that are actually taken up by fat cells, depend on many factors besides total calorie count.

A nice paper that came out recently: https://www.sciencedaily.com/releases/2015/11/151119143445.h...

So, for example, person A can eat 3000 calories of cookies per day, but would gain weight on 3000 calories of rice. Person B could be the opposite. From the paper, it looks like genetics is a factor, though epigenetic factors and microbiome seem more important.


The question I responded to was along the lines of "Can calorie count reliably predict the effect on a person's weight?". Now my conclusion is that your answer that "The short answer is "no"" is wrong.

I don't see what fat cells have anything to do with this either.

As for your rebuttal of my points, it does not seem sequent. I made the point that two individuals eating the same food will gain weight differently. You then made the very same point by linking to another paper which by the way does not support what either of us said - as it measured individuals individual glycemic responses to different foods, which is not correlated with the body's calorie intake on the food.

Here's the full paper in case you did not read it (and for others to read if they'd like): http://www.sciencedirect.com.sci-hub.cc/science/article/pii/...

As for the paper, the graphics used represent outliers. Plus they in one example compared cookies and bananas. Both which have different metabolic pathways. Fructose is handled in the liver and glucose is not. When they compared bread and glucose the difference was not quite as drastic even when comparing outliers. Therefore it seems more like it has to do with varying ability in people's bodies efficiency to metabolise fructose and glucose.


>So, for example, person A can eat 3000 calories of cookies per day, but would gain weight on 3000 calories of rice. Person B could be the opposite. From the paper, it looks like genetics is a factor, though epigenetic factors and microbiome seem more important.

That's not at all what that paper says. It describes that blood glucose response to various foods can differ between people (and shows to extreme outliers as examples). Your interpretation with "3000 calories of cookies" vs rice is both not supported by the study, and also nonsense.

I'd look up the studies for this if I had the time, but: the actual correlation (relationship) between calories and weight gain/loss is extremely large, with the differences between most people of similar body types less than 200 calories/day.


Sigh.

Yes, it is well supported by the research, did you actually read it?

I actually had a nice phone call with the lab that produced this paper. You can explain a percentage of weight changes by calorie intake, but the factors that explain glucose curves (and thus uptake of calories) require far more data (like genetics, etc).


Your call with the lab is an attempt to appeal to authority. Also, thanks for the "sigh".

I read your link. It's about blood glucose. Not about weight. The crux of your argument is that blood glucose response equals uptake of calories, which is not supported by your link, and which is not true. If it were, you could eat 5000 calories of fat in a day, have no blood glucose response, thus not get fat.

Are you really trying to claim that the outlier participants of whom the blood glucose plots are shown in your link are unable to use any of the calories in bananas/cookies, because they had no blood glucose response?


Apologies, but the "sigh" was for the "not supported by the study, and also nonsense" comment. I find it annoying when supported arguments are dismissed out of hand without compelling counter evidence. It sounds childish, like "no you are wrong, because naaaah". If that wasn't what you meant, please be more thoughtful.

Regardless, we can talk about metabolic pathways. If you consume carbohydrates, they eventually get dumped into your bloodstream as glucose (minus fructose, which is special). The level of glucose then absorbed into fat cells is regulated by insulin, and insulin production (while more complicated) is determined by the level of glucose in the blood.


At the extremes the effect on the weight is very predictable. Keeping everything else the same when you reduce your calorie intake to zero, you will reduce weight. Or increase your intake to 3 x recommended daily values and your weight will go up.

Everything in between is affected by cumulative margin of error. There are inaccuracies when calories are calculated, then variations of portions, variations of individual metabolism and compositions of gut bacteria. If you throw the "not all calories are equal" in the mix you get even more variations.


To directly answer your question: if you want to use a heuristic for losing weight, it should not be to count just carbohydrates or just fats or both together -- but your total calorie intake.


No, because different people have different metabolism. Think of it as if the body has a "target" weight. It actively tries to reach that weight and can compensate overeating (easily, by throwing away excess food) and undereating (not as easily but still can compensate a lot). This mechanism interferes heavily with your diet and that's the reason you can't easily change your weight at will by changing your diet. It changes over time if you permanently change your diet and lifestyle, but takes years.


The body is homoeostatic and will try to repel any change in body composition and weight. While it is also correct that different people have different metabolism and gut flora that affects our calorie conversion from different foods, the answer is yes. If you count your calories reliably, you can reliably lose weight by adjusting your calorie intake to match your body. If you throw out your body's own function of regulating its weight by measuring your food, you can accurately predict what you'll weigh in, for example, five months. It does not take years.

Noteworthy however is that with change to body composition, your TDEE (known as the amount of calories your body needs to maintain its current weight) changes. However it can easily be accounted for when losing (or gaining as may be the desired outcome for some people) in a controlled way.

Regarding the different metabolism thing: https://examine.com/faq/does-metabolism-vary-between-two-peo... (To asnwer the link's question: Yes. 600 at most calories if you compare two outliers.


This also requires overriding millions of years of evolution and multiple levels of body systems all screaming "you're hungry, EAT EAT EAT".

You can kick a heroine habit by quitting. You can never stop eating. How successful do you imagine most junkies would be if the standard advice was "measure the amount of heroine you take per day and stay below your target".


>Can the calorie count reliably predict the effect on a persons weight?

Yes. There was a MIT (or something) prof that went on a mission to prove this. Ate crap junk food...but counted the calories...and lost weight.


> ..you can also download the food database to a handheld compUter.

I'm going to start referring to smartphones as "handheld computers".


This is a question that's itched me constantly for over 15 years that I never bothered to look up. Anyone else?




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