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How do food manufacturers calculate the calorie count of packaged foods? (2003)

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Re: How do food manufacturers calculate the calorie count of packaged foods? (2003)

#51
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?

Re: How do food manufacturers calculate the calorie count of packaged foods? (2003)

#52
post #49

Earlier quoted context omitted.

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 w…

>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…

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).

Re: How do food manufacturers calculate the calorie count of packaged foods? (2003)

#53
post #51

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.

Re: How do food manufacturers calculate the calorie count of packaged foods? (2003)

#54
post #13

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?

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.

Re: How do food manufacturers calculate the calorie count of packaged foods? (2003)

#55
post #53
post #51

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.

Re: How do food manufacturers calculate the calorie count of packaged foods? (2003)

#56
post #27

> 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. C…

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

Re: How do food manufacturers calculate the calorie count of packaged foods? (2003)

#57
post #27

> 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. C…

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-...

Re: How do food manufacturers calculate the calorie count of packaged foods? (2003)

#58
post #13

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.

Re: How do food manufacturers calculate the calorie count of packaged foods? (2003)

#59
post #27

> 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. C…

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.

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.

Re: How do food manufacturers calculate the calorie count of packaged foods? (2003)

#60
post #50

Earlier quoted context omitted.

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

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: s…

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...

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