To not understand the puréed fruit thing?

[DeadGood]

So whole fruit is ok. Mashed fruit is ok. But puréed fruit is not.

Why? I've read something about sugars being released but it makes no sense to me.

When you chew, your body starts producing saliva, so your body is in effect doing two things at once. Chewing starts the breakdown of the cells in the food and when it gets to your stomach, the acid continues that work. The energy is released more slowly than if you gulped down a smoothie, as the blender has effectively done the work of the chewing action and the stomach acid in breaking down the energy to a form in which it is released. Therefore the body gets a quicker stronger "hit" than if the actual fruit was chewed, over a longer period of time.

That's my understanding anyway. I'm very much prepared to be corrected if I'm wrong though.

"Today 21:47 LoisEighty

Normal pureed fruit is fine.

'Sweetened with fruit puree' puree in baby yoghurts etc is super concentrated until it is basically just sugar with no other nutritional value.

Juices/smoothies lack fibre and have loads more sugar than you would consume if eating fruit eg. you wouldn't sit down and eat 6 oranges in one go."

Can someone on here who knows more than I do confirm or deny paragraph 1?

Paragraph 2 - dig.

Paragraph 3 - here we have a familiar confusion in terminology that I think sabotages these sorts of discussions. Smoothies to me contain whole fruit. I get why juice is bad. But to me, it's less to do with the "filling" thing (though that is part of it) and more to do with the lack of fibre. Surely?

And is this what tarla (first reply) was thinking of when she mentioned density - does that apply to juice only, or also purees?

Monosaccharides
The simplest biologically important carbohydrates are monosaccharides, meaning one sugar (mono = one, saccharide = sugar). The general formula for any carbohydrate is (CH2O)x where x is any number between three and eight. The most common monosaccharides (hexoses) are glucose, galactose, and fructose.

Glucose is the simplest monosaccharide and probably the most familiar sugar, especially if you have been in the hospital. In nature, glucose is the sugar that green plants produce during photosynthesis. It is also the main source of energy for cells. Medical procedures often require a glucose IV for recovering patients to regain their strength more quickly. Galactose is found in milk, and fructose gives fruit a sweet flavor. Although the chemical structure of each sugar differs, the chemical formula is the same: C6H12O6.

Disaccharides
Monosaccharides are joined together by dehydration synthesis to form disaccharides, or double sugars (di = two). The dehydration synthesis reaction releases water dehydration as a by-product. The most common disaccharide is sucrose, also known as table sugar, C12H22O11. Other common disaccharides include maltose (malt sugar) and lactose (milk sugar).

Polysaccharides
Further dehydration adds more sugar molecules together to form long chains known as polysaccharides. A polysaccharide generally refers to a carbohydrate polymer consisting of hundreds, even thousands of monosaccharides covalently bonded together. Cells use polysaccharides for a number of reasons, including the storage of excess glucose as starch in plants and glycogen in animals. The large polysaccharide cellulose is a structural component found in plants that gives them their rigidity and flexibility.

Spiking.

Yes, it's a bad thing. See frameymcframes comment about insulin.

From a website about biology.

"As someone who has a smoothie for breakfast every day ... I'll be fucking gutted if I may as well start the day with a can of coke"

Exactly grumpy! It's depressing because I feel like I can never rely on my common sense to tell me when something is healthy, because someone will run up to me and shout "don't you know kale gives you heart attacks if you eat it on a THURSDAY?!" or some other such shite

So basically the longer the sugar chain (polysaccharide) the harder it is to digest and the healthier it is???

"When you chew, your body starts producing saliva, so your body is in effect doing two things at once. Chewing starts the breakdown of the cells in the food and when it gets to your stomach, the acid continues that work. The energy is released more slowly than if you gulped down a smoothie, as the blender has effectively done the work of the chewing action and the stomach acid in breaking down the energy to a form in which it is released. Therefore the body gets a quicker stronger "hit" than if the actual fruit was chewed, over a longer period of time."

This to me goes back to the "chewing makes you lose weight so if you don't chew you will be fat" argument. It's missing the insulin part of the argument.

I simply cannot believe that the physical act of chewing, and the body producing saliva, and the stomach doing its work, all added together, makes a significant enough difference to warrant this discussion.

The insulin thing, I can get behind. But the above seems like an incomplete argument to me - is it? Anyone know?

This baffles me too. I remember a friend doing slimming world told me that a whole banana was one syn (or point, or whatever) but a mashed banana was five - my brain could not compute that at all.

I think it's to do with the way it changes the Glycaemic Index/Load of the fruit?

In the same way that cooking changes GI content, so a baked potato has a very high GI and boiled spuds a much lower one.

Or summat.

deadgood There's a recent (Harvard) study that links our increase in consumption of fruit juice to type 2 diabetes and obesity. (i don't know if it applies to smoothies etc). so it seems possible that this "spike" is not a good thing.

maybe it has to do with something I noticed but could never explain-
when dcs were litte (100s of years ago) they all ate a LOT of mashed banana- I could never figure how the volume of the banana decreased so much when you mashed it
does anyone know????

"Processing — juice has a higher GI than whole fruit; mashed potato has a higher GI than a whole baked potato, stone ground whole wheat bread has a lower GI than whole wheat bread."

<a class="break-all" href="http://www.diabetes.org/food-and-fitness/food/what-can-i-eat/understanding-carbohydrates/glycemic-index-and-diabetes.html?referrer=www.google.co.uk/" rel="nofollow" target="_blank">www.diabetes.org/food-and-fitness/food/what-can-i-eat/understanding-carbohydrates/glycemic-index-and-diabetes.html?referrer=www.google.co.uk/

It is to do with polysaccharides -but specifically cellulose.
All plant cells have a wall made out of cellulose. Your body can't digest cellulose - it is 'fibre'. (animal cells don't)
Basically you can imagine a plant cell as a tin can full of goodness (and sugar) and fruit is made up of lots of those tin cans packed tightly together.
The only way you can get those tins open is by chewing. So when you eat eg an apple you only get some of the calories/sugar it contains - relatively big chunks will go straight through you more or less intact. (Why you see whole peas/sweetcorn in your poo).
Stick an apple in a processor and more of the cells will be ruptured (more tins opened). Also digesting food takes quite a lot of energy -chewing, churning up in your stomach etc all uses energy. Liquid fruit takes less energy.
Starch (polysaccharide -or complex carbohydrate) is basically a long chain of glucose molecules. An enzyme in your mouth and stomach break it down into individual glucose molecules that can be absorbed in the gut. It is really rapid - starts in your mouth - have you ever been eating something thickened with starch - like custard or gravy - with a spoon and put the spoon back in, left it for a while and then noticed it has gone all runny? That was the enzyme in the saliva on the spoon breaking down the starch (baby rice is another eg)

Cellulose is 'identical' to starch -in that it is a chain of glucose molecules but they are linked in a slightly different way and your body doesn't have the enzyme needed to break the link. (pretty sure that what the appendix was for -digesting cellulose. Why animals that are vegetarians still have large appendixes -also why cows regurgitate their food and 'chew the cud' - more chewing to break down more cellulose plant walls...) the only way you can get into a plant cell is through mechanical digestion - basically chewing.

I did forget all about the insulin side of things.

Chewed food is still fairly substantial when it's being swallowed- it doesn't usually get ground down during the process of chewing to the same level of smoothness as a smoothie for example. So it's bulkier in the stomach, filling you up more? It's easier to eat a smoothie that consists of 2 peaches, an apple, a carrot and a banana than it is to sit down and physically chew the food. I'd be feeling full after a banana, bursting full after a banana and a peach and I would be feeling like I was going to be ill if I ate another whole piece of fruit/veg. I would probbaly not feel bursting full after a smoothie containg all of the above.

Yes - food after chewing is bulkier too - so it makes you feel full quicker (and also there is more bulk going through your intestines -which is a good thing for bowel health) you couldn't eat as much fruit whole as you can in one smoothie
All you have to do is imagine a liquidiser blade spinning and think how long it would take you to chew something as effectively as one blade spin.
(in labs we sometimes use what are basically liquidisers to smash open eg bacterial cells to get to the contents inside)

Imagine the sugar as sugar cubes, all tied up and tied together with string. Digestion has to unknot the strings which takes time and the sugar is released slowly. Pureeing or juicing the fruit breaks the bonds so all the sugar is digested quickly.

Fast release of sugar leads to a large release of insulin which stores the sugar as fat if it isn't used immediately. Insulin also causes hunger, as does the blood sugar level crash following the spike, which leads to cravings for more sugar.

Slow release of sugar means there isn't one huge gush of insulin, the sugar can be used as it is entering the bloodstream and it avoids the eat-high-low-eat vicious circle.

Deagood
It's depressing because I feel like I can never rely on my common sense to tell me when something is healthy, because someone will run up to me and shout "don't you know kale gives you heart attacks if you eat it on a THURSDAY?!" or some other such shite

Omigawd we had kale last Thursday! (rushes off to telephone 101)

I know where everyone is coming from though - I bliddy HATE science!

Axolotl
Imagine the sugar as sugar cubes, all tied up and tied together with string. Digestion has to unknot the strings which takes time and the sugar is released slowly. Pureeing or juicing the fruit breaks the bonds so all the sugar is digested quickly

Now THAT I can make sense of! Thank you axolotl. I hope you grow up to be the world's best salamander

I don't know the why or how but I do know 100% for me that purees are far worse for me that the same amount of whole fruit. Cooking it is also "bad".

I'm diabetic and I've experimented with blood sugar readings eating the same fruit prepared different ways. Purees give me a big blood sugar spike.

The Dr Robert Lustig book, Fat Chance, the Bitter Truth about Sugar
Really explains all this well. Many foods and drinks act just like pure sugar, fruit juice and smoothies are particularly bad as they're generally thought of as 'healthy' when in fact they're doing quite a lot of damage.

The insulin response has been implicated in heart disease and stokes, and other health problems because it's dumping substances in the blood that can lead to furring of the arteries. So yes, even if you're stuck thin, spiking your insulin isn't good for you, and as you get older your body starts to deal with it less well.

Stick thin not stuck thin

" So when you eat eg an apple you only get some of the calories/sugar it contains - relatively big chunks will go straight through you more or less intact. (Why you see whole peas/sweetcorn in your poo)."

This makes sense!

I saw an NHS dietician due to ibs. She told me to try cutting down on my fibre to see if that helped. She told me to puree the fruit and veg I ate as that reduces the fibre. (sadly reduced fibre did not help my ibs at all).

I think it was on one of the trust me I'm a doctor episodes on BBC that they said that eating veg raw is healthier than veg as you're body has to work harder to process it. There was also sons crazy thig about cold pasta being healthier for similar reasons I think.