The calorie delusion: why food labels are wrong

[brikis98]

The calorie delusion: Why food labels are wrong by Bijal Trivedi

This article contains lots of interesting evidence that indicates that the type of food we eat is just as important as the quantity. For example, the number of calories listed on the labels of food can be off by as much as 25% because they do not take into account numerous factors, such as the widely differing amounts of energy it takes to digest different foods. If you're struggling to lose weight, the source of your calories may be just as influential as the total amount.

Discuss.

 

[Megatomic]

Thanks for the link. Coming from The New Scientist there's probably a lot of credibility to this. I can't read it now (at work) but I will when I get home.

ps - I'm one of those struggling to lose weight. I work a fairly physically demanding job, run 40 to 60 (and rising) miles a week, ride my bike, and do 3 strength workouts a week. I watch what I eat pretty closely and rarely fall off the wagon. And yet I can't seem to lose that last 10 pounds... Talk about frustrating.

 

[StageLeft]

I'm sure there is something to this and I have wondered it in the past. A calorie is measured by burning the food or something similar, so if it's determined that a gram of fat in front of a bunsen burner has 9 calories and sugar has 4 and protein has 4, what does it do in my body? Surely a gram of powdered whey protein hits my bloodstream with better efficiency than a gram of raw chicken. So maybe after considering metabolic loss or expense to digest the food a gram of protein should be 3.5 calories.

I've also never looked into or known to what extent food temperature plays a role. Surely an icy glass of coke burns more calories than a regular room temperature one, although the math on that would be pretty easy to figure out (I just haven't bothered) and probably only amounts to a few calories/glass.

The numbers there for the egg at the end of page 2 are pretty substantial.

I agree the system is a good ballpark, though. If you're doing 2500 calories/day with a particular overall approach to eating and you're flatlined, if you lower the calories to 2000/day and eat generally the same things, you will know that you're taking in 80% of the nutrition.

ps - I'm one of those struggling to lose weight.

That goes for most of us Even when I've been in great shape I've never been 100% happy with my bodyfat. I always feel there is some better progress to be made, this after 15 years of going at it!

OK so I'll bother now. A kilocalorie raises by 1 celcius a milileter of water, or a "calorie" as we use them raises a kilogram (1000 ml) of water 1 celcius, so a glass of water at a 6 celcius has to be raised up by 30 degrees to reach body temperature when consumed. If the glass is 1/3rd of a kilogram, it expends 10 calories--assuming the body is 100% efficient at raising its temperature. Similarly a cup of warm water at 66 celcius would require the same calories when consumed to bring its temp down in the body via sweating. I don't know which process is more efficient. I recall reading that being in a sauna can burn quite a few calories over time. The moral here, though, is that if you drink a liter of ice water each day you'll get at least 30 calories burned simply by its consumption. I typically have a couple of them, I suppose in the grand scheme it has some mild positive effect on burning energy.

 

[brikis98]

Originally posted by: Skoorb
I'm sure there is something to this and I have wondered it in the past. A calorie is measured by burning the food or something similar, so if it's determined that a gram of fat in front of a bunsen burner has 9 calories and sugar has 4 and protein has 4, what does it do in my body? Surely a gram of powdered whey protein hits my bloodstream with better efficiency than a gram of raw chicken. So maybe after considering metabolic loss or expense to digest the food a gram of protein should be 3.5 calories.

I've also never looked into or known to what extent food temperature plays a role. Surely an icy glass of coke burns more calories than a regular room temperature one, although the math on that would be pretty easy to figure out (I just haven't bothered) and probably only amounts to a few calories/glass.

The numbers there for the egg at the end of page 2 are pretty substantial.

I agree the system is a good ballpark, though. If you're doing 2500 calories/day with a particular overall approach to eating and you're flatlined, if you lower the calories to 2000/day and eat generally the same things, you will know that you're taking in 80% of the nutrition.

ps - I'm one of those struggling to lose weight.

That goes for most of us Even when I've been in great shape I've never been 100% happy with my bodyfat. I always feel there is some better progress to be made, this after 15 years of going at it!

OK so I'll bother now. A kilocalorie raises by 1 celcius a milileter of water, or a "calorie" as we use them raises a kilogram (1000 ml) of water 1 celcius, so a glass of water at a 6 celcius has to be raised up by 30 degrees to reach body temperature when consumed. If the glass is 1/3rd of a kilogram, it expends 10 calories--assuming the body is 100% efficient at raising its temperature. Similarly a cup of warm water at 66 celcius would require the same calories when consumed to bring its temp down in the body via sweating. I don't know which process is more efficient. I recall reading that being in a sauna can burn quite a few calories over time. The moral here, though, is that if you drink a liter of ice water each day you'll get at least 30 calories burned simply by its consumption. I typically have a couple of them, I suppose in the grand scheme it has some mild positive effect on burning energy.

Yea, I think the general trend was that the more processed & prepared food is, the easier it is to digest. The trend in Western society has been to eat extremely processed things, which could go a long way to explaining why obesity has become such a big problem.

 

[Kipper]

I don't particularly think that these proposed changes are of much merit. First of all, there is enough consumer confusion over how to read food labels (believe it or not). Throw in more information (how an item is cooked, are you nuts?!) and you are going to give consumers information overload and leave practitioners to sort and organize the mess. As Marion Nestle says in the article, any changes are generally not going to be particularly significant at the clinical level. Moreover, the assumption is that people actually LOOK at food labels and understand them (which they don't and may not).

I think the article does an incredibly good job of blowing the significance of these minute differences in kcal counts out of proportion. For example, with respect to dietary fiber, even if we were to assume that people were somehow deriving the full calories from dietary fiber (which they aren't), the 38 g/day recommended for men 18-50, for example, would translate into a whopping 152 calories per day. Hardly a figure which could be responsible for triggering an obesity epidemic (recall that the food supply in terms of calories/citizen/day has expanded by far, far, far, more. Combine that with the generally low fiber intakes in Americans (usually <20 g/day) and it's not a particularly convincing argument. There are also dozens of types of dietary fiber, including some forms that cannot be fermented. Consider also variations in gut flora between populations. I'm far from an expert on this matter, but I think that these are important variables which the article does not address.

With respect to the suggestion that protein kcals be reduced "20%" from 4 to 3.2 kcal/g, once again, not exactly how this makes a huge difference. The average American protein intake is around 1.2 g/kg. For a 70 kg male, that's 84 g. Under the conventional system, this translates to 336 kcal/day, and under the proposed system that would mean that I'm actually in a surplus of slightly under 70 kcal/day. Maybe significant over a year, a decade, but this assumes I'm eating the same amount day after day after day - and as we all know diets and intakes fluctuate. Over a decade? They fluctuate wildly (which is one of the problems with measuring intake in long-term nutrition studies).

I am also dissatisfied with the use of percentages (for shock value) rather than actual kilocalorie counts when discussing the digestibility of food and the subsequent energy yield. What does "25%" mean? 250 calories or 2.5? Big freakin' difference. Overall, an interesting (if quite limited) insight into never-ending academic debates over what constitutes the "exact value" of something, but in general, very little real-world impact/effect. Brikis, you have a interesting point about prepared and processed food but processed foods (albeit perhaps not as processed as today) have existed for hundreds of years and obesity has ballooned over the last twenty years. White flour, white rice, sugars and oils have been in use for centuries - but no obesity crisis. People are in search for the "prime mover" of this public health crisis when all signs point to the fact that it is a multifaceted, multifactoral problem. One thing is for sure, however. The ubiquity and cheapness of high-calorie food is a major driver. I don't think it has as much to do with the processing than it does to do with the fact that processing is where all the profit ("added value") potential lies. If there were significant profits in marketing unprocessed foods they would be ubiquitous, and we'd have the same problem. As I see it, obesity is less of a quality issue than a quantity issue, although they are certainly intertwined (along with all the other obesity "variables").

 

[theeedude]

That's why I don't chew my food that much