9 ms·

Walnuts Have Fewer Calories Than the Label Suggests

42 points by nkurz 11y ago

nostromo 11y ago
> The study was partially funded by the California Walnut Commission.
- Avshalom 11y ago
  I mean yeah but on the other hand, who the hell else would bother funding calories-in-nuts studies?
  - blakesterz 11y ago
    Yeah, I kinda feel like that too. I'd like to think they saw the results of other studies and just thought "Oh wow it would be great if we see the same results on our walnuts. On the other hand, the California Nut Industrial Complex could just be pretty evil.
    - jessaustin 11y ago
      Maybe it's because I lived there a couple of years, but if I saw that phrase in another context I wouldn't think of walnuts and almonds. b^)
      - ant6n 11y ago
        https://en.wikipedia.org/wiki/Nut_(goddess) https://en.wikipedia.org/wiki/Nut_(goddess) ?
  - imaginenore 11y ago
    USDA.
- dnautics 11y ago
  if they had instead found that there were more calories, they could have branded it as 'a better energy food'...
blakesterz 11y ago
The full text is online: http://jn.nutrition.org/content/early/2015/11/18/jn.115.217372.full.pdf+html?sid=6785fd43-b687-408d-9d27-bf92ab7ca436 http://jn.nutrition.org/content/early/2015/11/18/jn.115.2173... Apparently studies have shown the same thing on pistachios and almonds too.
- hayksaakian 11y ago
  This is a study of 18 people. Take that with a grain of salt, but also realize that many studies on people tend to have really small numbers of people.
  - iopq 11y ago
    That only matters if results differ between each person. If everyone has the same results, 18 people is plenty to prove that the results are the same for everyone. It depends on the sample variance and the number of people. If you have high sample variance, you need a higher N to make it less likely that you have a sampling error. If you have very low sample variance, just a few people is enough.
    - thaumasiotes 11y ago
      > That only matters if results differ between each person. Well, we know that they do...
      - iopq 11y ago
        We actually DON'T know that. It could be every person gets almost the same result.
jessaustin 11y ago
The tag cloud is hilarious.
daveguy 11y ago
Judging from the amount that just passes right through I would have expected even less than 80% of the calories absorbed!
Bud 11y ago
We need more studies like this. For instance, I'd like one that reveals that steak and beer actually have negative calories.
- mikeash 11y ago
  It's true, but only if your steak is well done and your beer is Coors.
- pkaye 11y ago
  Then you need to form the steak and beer commission and fund a study.
pm90 11y ago
I wonder if this applies to all walnut-like families, such as pecans.
amluto 11y ago
Awhile back, I tried to find the actual studies that determined that sugar has 4 kcal/g and fat has 9. I failed. I couldn't even find a clear definition of what a kcal means. (Is it mechanical work you can do after eating it? ATP produced?) Given recent results, I wouldn't be at all surprised to learn that fat, in general, has less than 9 kcal/g or that sugar has more than 4.
- InclinedPlane 11y ago
  One calorie is the energy required to raise the temperature of one gram of water at 1 atm pressure by one degree Celsius, it is equal to about 4.2 Joules. A kilocalorie, or a dietary Calorie, is one thousand calories, or 4200 Joules. All of this is readily available from an innumerable number of sources. The calorie content of food is determined experimentally by burning the food in a calorimeter and measuring how much heat is produced (by, for example, measuring how much it raises the temperature of a water bath). This measures the energy content of the food, but does not measure the amount of energy your body can make use of as that is a very complex problem that would have a different answer in every individual due to variations in body size, metabolism, digestion, muscle mass, insulin activity, the ambient temperature, and about a zillion other factors.
  - deleted 11y ago
    [deleted]
  - NikolaeVarius 11y ago
    We haven't done that since the 1990's. Calorie content is calculated by measuring the amount of fat, protein, carbs in a food and extrapolating from that. It's pretty damn close.
    - niccaluim 11y ago
      Except, apparently, for walnuts. :)
    - InclinedPlane 11y ago
      Perhaps I wasn't clear, I said that's how calories are determined experimentally, I did not say that's how all calorie counts are generated.
dogma1138 11y ago
TBH that's true for most foods (not necessarily less but not exactly what the label says). The most common way of calculating the caloric value for food is by calculating the fat, fatty acids, proteins and carbohydrates by weight and assigning them the common caloric value this in itself is not accurate to begin with. The more accurate way is going to be by testing the overall caloric potential of the food before digestion and then checking the caloric value of the fecal mater after digestion, but that isn't something easy to do. If you are selling a hand made sandwich that data might be available for most ingredients and you'll end up having quite an accurate caloric value. But with many processed and mass produced food products that's simply not the case as it's quite hard to estimate what exact caloric value your body would extract from each portion with so many ingredients from various sources. The biggest problem is that not all foods are digested the same way this is both universal e.g. foods with higher percentage of non soluble fibers reduce the caloric value (10-30%) and non-universal per person specific metabolism, your personal digestive track biome and many other factors like how much activity have you done before and after eating. Eating a more or less rounded meal on an exact schedule and a very mild exercise (like a casual walk) shortly after the meal can reduce the amount of calories your body extracts from the food quite considerably. Now it's true that genetics and some other circumstances play quite a big role, but eating on schedule and not sitting straight after heaving your food can do wonders for some one who is trying to either lose or maintain weight. Yes burning a couple 1000's of extra calories a week at the gym can do wonders but in many cases it's not as effective as proper diet management and diet management isn't about counting calories is about finding a good combination of what your body will digest well but not over digest and teach your body that it doesn't need to hoard everything because it knows that the next meal will come on time. When you eat regularly and induce a system in which your body would rather metabolize what it needs straight away and use that instead of hoarding everything and converting it to fat while burning your glucose reserves (which what induces the odd hour cravings) works better than just counting calories. You can have 2 people eating at exactly their BMR with the same caloric intake and outtake and one would lose weight and the other would gain it just because one eats regularly 4-5 times a day and the other eats irregular meals and snacks when they feel hunger.
- bjterry 11y ago

42 points by nkurz 11y ago

nostromo 11y ago

> The study was partially funded by the California Walnut Commission.

Avshalom 11y ago
I mean yeah but on the other hand, who the hell else would bother funding calories-in-nuts studies?
- blakesterz 11y ago
  Yeah, I kinda feel like that too. I'd like to think they saw the results of other studies and just thought "Oh wow it would be great if we see the same results on our walnuts. On the other hand, the California Nut Industrial Complex could just be pretty evil.
  - jessaustin 11y ago
    Maybe it's because I lived there a couple of years, but if I saw that phrase in another context I wouldn't think of walnuts and almonds. b^)
    - ant6n 11y ago
      https://en.wikipedia.org/wiki/Nut_(goddess) https://en.wikipedia.org/wiki/Nut_(goddess) ?
- imaginenore 11y ago
  USDA.
dnautics 11y ago
if they had instead found that there were more calories, they could have branded it as 'a better energy food'...

blakesterz 11y ago

The full text is online: http://jn.nutrition.org/content/early/2015/11/18/jn.115.217372.full.pdf+html?sid=6785fd43-b687-408d-9d27-bf92ab7ca436 http://jn.nutrition.org/content/early/2015/11/18/jn.115.2173... Apparently studies have shown the same thing on pistachios and almonds too.

hayksaakian 11y ago
This is a study of 18 people. Take that with a grain of salt, but also realize that many studies on people tend to have really small numbers of people.
- iopq 11y ago
  That only matters if results differ between each person. If everyone has the same results, 18 people is plenty to prove that the results are the same for everyone. It depends on the sample variance and the number of people. If you have high sample variance, you need a higher N to make it less likely that you have a sampling error. If you have very low sample variance, just a few people is enough.
  - thaumasiotes 11y ago
    > That only matters if results differ between each person. Well, we know that they do...
    - iopq 11y ago
      We actually DON'T know that. It could be every person gets almost the same result.

jessaustin 11y ago

The tag cloud is hilarious.

daveguy 11y ago

Judging from the amount that just passes right through I would have expected even less than 80% of the calories absorbed!

Bud 11y ago

We need more studies like this. For instance, I'd like one that reveals that steak and beer actually have negative calories.

mikeash 11y ago
It's true, but only if your steak is well done and your beer is Coors.
pkaye 11y ago
Then you need to form the steak and beer commission and fund a study.

pm90 11y ago

I wonder if this applies to all walnut-like families, such as pecans.

amluto 11y ago

Awhile back, I tried to find the actual studies that determined that sugar has 4 kcal/g and fat has 9. I failed. I couldn't even find a clear definition of what a kcal means. (Is it mechanical work you can do after eating it? ATP produced?) Given recent results, I wouldn't be at all surprised to learn that fat, in general, has less than 9 kcal/g or that sugar has more than 4.

InclinedPlane 11y ago
One calorie is the energy required to raise the temperature of one gram of water at 1 atm pressure by one degree Celsius, it is equal to about 4.2 Joules. A kilocalorie, or a dietary Calorie, is one thousand calories, or 4200 Joules. All of this is readily available from an innumerable number of sources. The calorie content of food is determined experimentally by burning the food in a calorimeter and measuring how much heat is produced (by, for example, measuring how much it raises the temperature of a water bath). This measures the energy content of the food, but does not measure the amount of energy your body can make use of as that is a very complex problem that would have a different answer in every individual due to variations in body size, metabolism, digestion, muscle mass, insulin activity, the ambient temperature, and about a zillion other factors.
- deleted 11y ago
  [deleted]
- NikolaeVarius 11y ago
  We haven't done that since the 1990's. Calorie content is calculated by measuring the amount of fat, protein, carbs in a food and extrapolating from that. It's pretty damn close.
  - niccaluim 11y ago
    Except, apparently, for walnuts. :)
  - InclinedPlane 11y ago
    Perhaps I wasn't clear, I said that's how calories are determined experimentally, I did not say that's how all calorie counts are generated.

dogma1138 11y ago

TBH that's true for most foods (not necessarily less but not exactly what the label says). The most common way of calculating the caloric value for food is by calculating the fat, fatty acids, proteins and carbohydrates by weight and assigning them the common caloric value this in itself is not accurate to begin with. The more accurate way is going to be by testing the overall caloric potential of the food before digestion and then checking the caloric value of the fecal mater after digestion, but that isn't something easy to do. If you are selling a hand made sandwich that data might be available for most ingredients and you'll end up having quite an accurate caloric value. But with many processed and mass produced food products that's simply not the case as it's quite hard to estimate what exact caloric value your body would extract from each portion with so many ingredients from various sources. The biggest problem is that not all foods are digested the same way this is both universal e.g. foods with higher percentage of non soluble fibers reduce the caloric value (10-30%) and non-universal per person specific metabolism, your personal digestive track biome and many other factors like how much activity have you done before and after eating. Eating a more or less rounded meal on an exact schedule and a very mild exercise (like a casual walk) shortly after the meal can reduce the amount of calories your body extracts from the food quite considerably. Now it's true that genetics and some other circumstances play quite a big role, but eating on schedule and not sitting straight after heaving your food can do wonders for some one who is trying to either lose or maintain weight. Yes burning a couple 1000's of extra calories a week at the gym can do wonders but in many cases it's not as effective as proper diet management and diet management isn't about counting calories is about finding a good combination of what your body will digest well but not over digest and teach your body that it doesn't need to hoard everything because it knows that the next meal will come on time. When you eat regularly and induce a system in which your body would rather metabolize what it needs straight away and use that instead of hoarding everything and converting it to fat while burning your glucose reserves (which what induces the odd hour cravings) works better than just counting calories. You can have 2 people eating at exactly their BMR with the same caloric intake and outtake and one would lose weight and the other would gain it just because one eats regularly 4-5 times a day and the other eats irregular meals and snacks when they feel hunger.

bjterry 11y ago