Kj or Kcal

Dylan69

Guys,

What should i be looking at when looking at the back of the product?

I see KJ and Kcal and there is a big difference in them. I'm trying to look for least calories in the product!

rubadub

Most here will use kcal which is kilo calories, i.e. 1000 calories, since calories are so high in foods when people say "calories" they really mean 1000 calories. It should really be spelt with a capital "Calories", you only have to worry about this if you are a scientist but it can confuse some people. more nerdy stuff here http://en.wikipedia.org/wiki/Calorie

kJ is kilojoules, just a different measurement of energy, but proportional, think of miles and kilometres, they both increase at the same ratio.
1 calorie = 4.18400 joules

To calculate you should weigh your food, look for the kcal per 100g, this is the easiest to work with. Quoted portions are usually very small, since the marketers want it to appear low in calories. If it was 200kcal per 100g and you weigh out 30g then it is (30g/100g)*200=60kcal

I hate US packaging which some have adopted here, these rarely have the "per 100g" figures so it is harder to do the maths. Some like light bars want to hide the fact that they are small bars, like aero, wispa, creme egg. So many have kcal "per bar", which is harder again, the overall weight should be on the mulitpacks so you have to do even more maths.

And just to put my lab coat on again, it should not be written "Kj & Kcal ", it is "kJ and kcal", I had a lecturer who threatened to fail people who got it wrong, they can have different meanings and it does bug me since I have written/approved techincal documents only to get some arty-farty graphic designer to think it looks "nicer in upper/lowercase" and people think its my mess up, some even change the letters entirely to make them "sound better".

Eviledna

rubadub wrote: »

And just to put my lab coat on again, it should not be written "Kj & Kcal ", it is "kJ and kcal", I had a lecturer who threatened to fail people who got it wrong, they can have different meanings and it does bug me since I have written/approved techincal documents only to get some arty-farty graphic designer to think it looks "nicer in upper/lowercase" and people think its my mess up, some even change the letters entirely to make them "sound better".

:eek: As a graphic designer who also has a BSc, I'd be absolutely shocked to see any designer worth their salt make such a mistake continuously. Most designers I've had the fortune to work with are pedantic about spelling etc. Sounds like some of them are ruining reputations for the rest, eh?

OP, looking at the least calories in a product may seem like a good start, but don't forget to see where those calories are coming from also, are they calories from fat or protein or Carbohydrates? A balanced diet is just as important for health.

Mellor

OP, a much shorter answer, it doesn't matter.
They are the same, and neither is better or worse than the other

Eviledna

Well if the OP was looking for "calories"

I'm trying to look for least calories in the product!

Then kcal is the one to look at.

Turtwig

Not sure if this has been mentioned before but it is worth considering :

Calories not 100% accurate

It's basically about the method used to calculate calories of food, and how well that actually related to those the human body receives.
Don't always judge by the cover.

Mellor

Eviledna wrote: »

Well if the OP was looking for "calories"
Then kcal is the one to look at.

Not really, if she wanted to know the exact calories then obviously its easier to look at calories,
but she wants to compare products and find the one with the lowest calories, so its makes no difference which she compares. Lowest joules = lowest calories
Its best to get used to both as some products use one or the other.

rubadub

Mellor wrote: »

OP, a much shorter answer, it doesn't matter.
They are the same, and neither is better or worse than the other

Well they are both units of energy, but to say they are the same could confuse people. Many do not know how to calculate calories or WW points at the best of times, and that could confuse them more. It is the same as saying km and miles are "the same" and lb and kg are "the same". I don't like dumbing it down too much, I have heard some very twisted logic from people regarding calories & energy due to fundamental misunderstandings about what they are, it is worth having a basic concept of what they really mean.

Mellor wrote: »

Not really, if she wanted to know the exact calories then obviously its easier to look at calories,
but she wants to compare products and find the one with the lowest calories, so its makes no difference which she compares. Lowest joules = lowest calories
Its best to get used to both as some products use one or the other.

I would say stick with calories, most guides all use it, and I expect they OP is a following a calorie restriction program, like 2000kcal per day. I read every packet I buy, I have only ever seen one product in this country that only had kJ listed, it was imported.

Malty_T wrote: »

Not sure if this has been mentioned before but it is worth considering :

Calories not 100% accurate

It's basically about the method used to calculate calories of food, and how well that actually related to those the human body receives.
Don't always judge by the cover.

Yes, I have made this point many times, they did a study feeding people 500kcal of alcohol and 500kcal of sugar extra per day and the sugar drinkers got fatter. I think the WW points system would show a much greater variation too.

Mellor

rubadub wrote: »

Well they are both units of energy, but to say they are the same could confuse people. Many do not know how to calculate calories or WW points at the best of times, and that could confuse them more. It is the same as saying km and miles are "the same" and lb and kg are "the same". I don't like dumbing it down too much, I have heard some very twisted logic from people regarding calories & energy due to fundamental misunderstandings about what they are, it is worth having a basic concept of what they really mean.

to be honest, it was a pretty simple question, I felt that your post was long winded and might confuse people also. She asked about comparing two products, thats all my post refered to.

If she asked what should she track for the day, I would of said cals. (I count cals despite joules being dominant here)


And I never said the units are the same, so your miles/km simile is a bit condescending. I was refering to the product with the lowest in one is the same as the other.

I would say stick with calories, most guides all use it, and I expect they OP is a following a calorie restriction program, like 2000kcal per day. I read every packet I buy, I have only ever seen one product in this country that only had kJ listed, it was imported.

I still say be familar with both. In ireland you're right that cals is dominant, but with more and more people buying is places like aldi that import alot, or online, both is best. Its not unusual for somebody to go travelling, esp in this climate, alot of countries don't list cals. (current where I am, joules is listed 100%, cals 20%)

rubadub

Mellor wrote: »

And I never said the units are the same, so your miles/km simile is a bit condescending. I was refering to the product with the lowest in one is the same as the other

I wasn't trying to be condescending, your first post just simply said

Mellor wrote: »

OP, a much shorter answer, it doesn't matter.
They are the same, and neither is better or worse than the other

I was clearing that up to say that you meant they are "the same" as in both units of energy, just like miles of km are units of distance. I also explained that they are proportional scales. i.e. twice as many miles is the same as twice as many km. Another common think people use is degrees centigrade and Fahrenheit which are not proportional like that. I have met people who did not think miles per hour and km per hour were linearly proportional when the new speed limits came in.

You might have though I was condescending since you think it is blatantly obvious & simple, but it is certainly not. Like I said I have heard many bizarre assumptions about calories and energy in my time, my job involves a lot of it and it is fascinating to me how people can develop their own warped ideas and theories. I have a mate who was eating entire packs of go-ahead biscuits thinking they are good for him, another poster knew a woman who thought the more lean cuisine meals she ate the thinner she would get.

I did not want the OP thinking they were exactly the same and comparing kJ and kcal on 2 similar products, which I genuinely expect some people do. You can see in the WW points thread most are not able to calculate their points themselves.

The OP did not explicitly say they just were comparing 2 products, and expect they could benefit of further points even if that is all they wanted, I was also helping to explain how to really compare 2 similar products. I mentioned portion size which is also very important. From what I have experienced I expect there are lots of people eating huge portions of "low kcal per 100g" foods and deeming the likes of nuts "bad" since they are so calorie dense yet eating in smaller amounts.

Mellor wrote: »

to be honest, it was a pretty simple question, I felt that your post was long winded and might confuse people also.

And I felt your post was too simplified and could lead to further confusion or wrong assumptions being made. I do not think its a simple question at all, due to the usage I assume the OP will apply to the answer.