[nudephil (OP)]

For this week's question, listener Kelvin asks:

We are told not to overcook our vegetables because this kills the nutrients. Now if that's the case, why don't we just overcook the food we enjoy and not run the risk of putting on weight?

Any thoughts?

[charles1948]

For this week's question, listener Kelvin asks:

We are told not to overcook our vegetables because this kills the nutrients. Now if that's the case, why don't we just overcook the food we enjoy and not run the risk of putting on weight?

Any thoughts?

The overcooking of vegetables will destroy their healthy nutritional content - in the form of vitamins.  But it won't destroy their fat and starch content.  These contents will still make you put on weight

[CliffordK]

I don't believe charcoal has great nutritional value.

You may need to cook your food just a little more.

[evan_au]

Why doesn't overcooking unhealthy food make it healthy? ...(vegetables)

There is an implication here that vegetables are the unhealthy food in our diet.
- I think this is misdirection

In fact, the major sources of unhealthy diet in "Western" countries are:
- Excess calories, much of which comes from fats, most of which comes from meat
        - Another large contributor is added sugar (including sugary drinks and blended juices)
        - excess consumption of low-nutrition starchy foods (potato, bread, etc)
- Excess saturated fats, most of which comes from meat and heavily processed food (think fries, chips, pastries...)
- Excess salt, added to most foods (an order of magnitude higher than the recommended daily intake, sometimes twice the maximum daily intake)
- Lack of fiber, in most heavily processed foods
- Lack of exercise commensurate with calorie intake
- You will notice that the above list does not include an excess of nutrients from food (some people take additional nutrients from a bottle...)

If you throw in a few more considerations like accelerating deforestation and greenhouse impacts of agriculture, you come to conclusions like: Western cultures could eat healthier by:
- Cutting down on red meat consumption
- Cutting down on saturated fats (less meat) and increasing unsaturated fats (from fruit/vegetable sources)
- Cutting down on starchy vegetables (especially fried, like potato chips), and preferring more nutritious fruit and vegetables, preferably with high fiber
- Cutting down on added sugar and salt
- Look for a balanced diet with all the food groups
- Exercise more

PS: This is not to minimize the dietary problems of the non-Western world, which basically come down to malnutrition.

[CliffordK]

@evan_au,

Good point that fruit can be very sugary, but veggies don't have a lot of caloric content unless you add in a bunch of calorie rich dressings. 

But, it does add up some. All in moderation.

Nonetheless,you get quite a few more calories with that steak, cheesecake, ice cream, or all the carbs of various types you take in.

[evan_au]

veggies don't have a lot of caloric content unless you add in a bunch of calorie rich dressings

I agree that a raw potato probably doesn't have much in the way of human-extractable calories.
- But a boiled potato has more
- The more you boil it, the more calories become accessible
- Similar goes for taro, cassava, carrots, beets and other tuber-based vegetables
- As well as the raw calories, some of these will have more dietary nutrients in addition to the starch.

I heard of a Pacific Island nation whose emergency food supply was "hurricane taro".
- The tuber just grows unseen underground
- When a hurricane wipes out everything else, you dig up the tuber and cook it for food.

[charles1948]

On the point about "unhealthy food".

Suppose you were absolutely starving, having run out of all proper food

And all you had left was, say;

An old loaf of mouldy bread
A lump of mouldy cheese
A bunch of bananas whose outer skins were blackened, and when peeled, revealed contents in a similar state
A tin of sardines six years past the sell-by date printed on the tin

Then you put all of this into a big saucepan of water, and boiled it vigorously for an hour or so. With the lid on.

The result would presumably  be some kind of "soup".
Would this "soup" be safe to eat, on the grounds that the prolonged boiling had destroyed any microbes/pathogens?

I'm asking just in case it might come to that.  Best to be prepared

.

[CliffordK]

The result would presumably  be some kind of "soup".
Would this "soup" be safe to eat, on the grounds that the prolonged boiling had destroyed any microbes/pathogens?

I'm asking just in case it might come to that.  Best to be prepared

There are several issues with food safety. 

• Pathogens: Generally killed with cooking depending on the process, with the exception of a few very rare prions.  Simply browning the outside may not be enough.
• Biologic Toxins:  These come in a wide variety, some impacted by cooking some not. Some require high heats greater than normally used in cooking.  In some cases, they can be leached out of food with processing. 
• Metals, inorganic toxins, and certain small molecule toxins.  Not impacted by cooking, although they may be able to be leached out

Rapeseed is mildly toxic, but the oil can be extracted and is edible.

Anyway, cooking your moldy bread may render it harmless, or it may not.

Botulism Toxin is deadly, but generally rendered safe with significant cooking.
Staph Aureus Toxin is more mild "food poisoning", but is quite heat resistant.
Cyanide C≡N is also resistant to heat.
Obviously metals generally would not be removed by cooking, but could have oxidation states impacted.

I can't say about your concoction.  It may be safe, or it may not.  It would depend on the specific organisms involved.  Note that "blue cheese" is a "moldy cheese" that is edible  and very popular.

[alancalverd]

An old loaf of mouldy bread
A lump of mouldy cheese
A bunch of bananas whose outer skins were blackened, and when peeled, revealed contents in a similar state
A tin of sardines six years past the sell-by date printed on the tin

I'd think twice about the bread - some wheat moulds are poisonous
I'd scrape the fluffy bits off the cheese and avoid any red bits, but a hard blue or green mould is pretty normal on posh cheese.
Overripe bananas are an excellent food source. What they lack in vitamins is more than compensated by the rapidly digestible sugars.
The sell-by date on a tin of sardines is pretty meaningless. Most modern canned food is edible for 50 years or so if the can isn't actually corroded. Surströmming (fermented herring) is an acquired taste but harmless.
A balanced meal. Eat it raw.

[Adam Murphy]

Hello, thank you all! This question has now been answered, and you can find it here: https://www.thenakedscientists.com/podcasts/question-week/can-overcooking-junk-food-make-it-healthy

[Zer0]

Overcooking!

Yep, one could set fire to burgers & fries... Literally burning it up.
🍔🍟🔥🔥🔥
But then Obviously, that would Not remain on the list of " The Foods that We Enjoy ".
😑


P.S. - Unhealthy can directly be proportional to the Quantity.
Too much Coffee can Kill you, whereas too little of botulinium toxin can give you a facelift.
(LD50)
🖖

[jullia]

In my opinion, If you're eating a limited diet, you are at risk of some kind of nutrient deficiency. Which kind, I have no idea; the odds are good that nobody has even heard of it. It varies from person to person, based on biochemistry and gut biota. You might well fare poorly on a diet that works for me, and vice versa. but intake limited food we cant get proper mineral or vitamins.