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Is Food Fungible? (& WTF does that mean?)

Is food fungibleAs the old saying goes, “opinions on diets are like a%&holes...everyone’s got one”. That’s no lie.

One of the problems with the ‘diet wars’ is that there’s no hard and fast way to settle the truth.  You can’t just take a look at a bro’s physique and deduce the truth of their preferred diet because the fact is, people succeed on all sorts of diets, and people tank on all sorts of diets.


So what’s a gal or fella to do?  Short of trying every diet consecutively (I’ll ask you how that went in 23 years’ time) and short of waiting for science to stumble on a unified theory of dieting (that’ll be another 68 years...at least), I reckon the only reliable method is to do something really and truly unpleasant.  Yep, that’s right...I reckon you have to actually think about it.


So, in that spirit, I think it might be worth learning a new word or two, and the first cab off the rank is that funky word in the title, “fungible”.


Basically, a thing is fungible if it is interchangeable with something else, without losing any of the significant features of that thing in the substitution.  So, for example, a can of coke is fungible; if I change it with another, there’s no significant difference.  Money is another great example of a fungible thing; one 10 cent coin is interchangeable with any other. Pets, on the other hand, are not fungible...no matter how hard parents may try, little Susie will not love her new black kitten just the same as the one you reversed over with the four-wheel-drive (although she might if she’s not aware of the substitution...just sayin’). Nor are paintings fungible...my kid’s finger painting will not substitute for a Picasso, even though both of them are essentially squiggles of paint on canvas.


So what’s all this got to do with diet?

iifymWell, one of the major battlegrounds in the diet wars revolves around the types of foods that serious trainers should be eating; on the one side, some folks reckon it’s gotta be ‘clean’ (think chicken breasts, oatmeal, and broccoli); on the other hand, some people reckon you can include all sorts of freaky grub in your diet, so long as you’re getting the basic nutritional building blocks ( the so-called ‘If it fits your macros’ approach:  http://www.iifym.com/ ).


Basically, what we’ve got here is an argument about whether or not foods are fungible. That is, whether or not you can simply interchange one type of food for another, without changing anything significant in the process.


So, who’s right?  Well, this is going to come as no major surprise to all those that have got their thinking caps on, but the answer is, “they both are”.


Let’s have a brief look at the ways in which foods are fungible, and the ways in which they aren’t:


Fungible: foods contain calories.

Thai-Chicken-with-Cashew-Nuts-RecipeWell, duh. As we all know, foods contain energy (which we measure in the form of calories or kilojoules), and these units of energy are completely fungible.  Whether you get 1000 calories from grilled chicken breast or 1000 calories from deep-fried chicken nuggets, you still have 1000 units of energy in your system.  While this is a pretty obvious point, some folks do manage to forget it, most often when they underestimate the energy content of ‘healthy’ foods (e.g. “I can’t figure out why I’m not losing weight - I’ve added a salad to every meal!”). You can actualy gain weight eating ‘clean’ foods (e.g. sumo wrestlers) and you can lose weight eating shite (e.g. the Twinkie diet:  http://edition.cnn.com/2010/HEALTH/11/08/twinkie.diet.professor/index.html).


Bottom line: you need to know how many calories you’re taking in, no matter where those calories are coming from.

Fungible: foods are composed of macro-nutrients.

Ok, so this is where the ‘If it fits your macros’ diet gets its motor running.  The basic idea is that it is the amount and proportion of macronutrients (i.e. protein, carbs, fats) in the diet that most heavily influences body composition, NOT the particular foods that supply those macronutrients.  This idea trades on the fact that macronutrients are distributed through all food types; whether you’re eating steamed fish soup with rice noodles and sesame oil or beer-battered fish-n-chips, you could be getting the same spread of protein, carbs, and fats. And, as far as nutrition and body composition, the macros (assuming calories are equal) count for more than anything else in terms of final outcomes. If it was a choice between eating nothing but McDs Sausage-n-egg McMuffin on the one hand or nothing but organic lettuce on the other hand (yes, truly an excruciating choice), I’d be hopping in the Datsun 180b and heading to the drive-thru, pronto.    

Bottom line: you need to know what your macronutrient totals and proportions are, no matter where those macronutrients are coming from.


cooked baconNot fungible: foods have different effects on hunger and appetite.

Even if the calorie and macronutrient contents are equal, one type of food is not necessarily going to have the same effect on your hunger and appetite as another. For example, eating 400 calories of canned tuna and peas is going to have a very different effect on your hunger levels than eating the same 400 calories in a protein bar (hint: one will leave you feeling very full, the other probably won’t).  While the reasons behind these variations are very complex, the basic facts are that whole, unprocessed foods tend to promote satiety (i.e.  you feel full for longer after you’ve eaten) and satiation (i.e. you get full sooner while you’re eating), while processed foods tend to be hyper-palatable (i.e. ‘more-ish’) and somewhat addictive.  Needless to say, you’re not going to comply with your cutting diet if you’re starving all the time, or fighting off a chronic case of the munchies from dawn till dusk.

Bottom line: you need to pay attention to the different effects that different foods have on your hunger and appetite, even if they have the same calories and macronutrients.


Not fungible: foods contain different micronutrients and chemical additives.

Sure, a spoonful of organic honey and a handful of jelly beans are about equal in terms of calories and macros, but the honey also contains vitamin B6, thiamin, niacin, riboflavin, pantothenic acid and the minerals calcium, copper, iron, magnesium, manganese, phosphorus, potassium, sodium and zinc (none of those in the jelly beans!).  Moreover, the jelly beans often contain artificial colours and flavours (which may cause symptoms in sensitive individuals, including hyperactivity). So, when it comes to your health (as opposed to your body composition), it may be a good idea to pay some attention to some of the other goodies (or unwanted extras) that you’re moving through your digestive tract.

Bottom line:  you need to pay attention to the different micronutrients and chemicals that are contained in different foods, even if they have the same calories and macronutrients.


I guess the take-home point here is that things are never as simple as they seem, nor are they as black and white.

Yes, foods are fungible, inasmuch as they are a carrier for calories and macronutrients (both of which play a huge role in terms of body composition).  But they’re also far from fungible with respect to their impact on hunger and appetite, and with respect to their impacts on your health.


As with all things, resist the urge to go to the extreme; you don’t need to eat like a food-nun, nor do you have any good reason for single-handedly keeping Cadbury’s and Coca-Cola in business.  It’s probably a pretty fine idea to base your diet on whole, unprocessed foods; amongst other things, they’ll keep you full longer, and help you live longer.  On the other hand, don’t pull out the flagellator if you feel like the odd indulgence; so long as your calories and macros are under control, you’re apples as far as body composition is concerned.


Find the balance...and don’t be fungible.


Next time, tune in for another exciting article uncovering the dietary relevance of the antidisestablishment movement.  Or not.

Harry avatarHarry Mavros is a philosopher, trainer and nutrition consultant (in no particular order).  He maintains that every person has unique needs, and therefore requires a specialised approach. No 'one size fits all' diet or training programs will be tolerated. He can be contacted at [email protected]

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