... why not just eat fruit and spare your body the effort of converting it? If someone does not have metabolic problems and is not trying to lose weight (heavens forbid!) then fruit is a good choice right?
whenever I eat complex carbs I end up feeling incredibly tired, whereas if I eat fruit alone (bananas) it doesn't happen
asked byHuntingBears (4176)
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on March 28, 2013
at 02:32 PM
There are plusses and minuses in the types of sugars out there. Complex carbs and simple refined carbs will turn into glucose, which can spike your insulin, depending on how long it takes for your body to break down. Your questions asks, why spare your body the effort of breaking down carbs, the answer is that it is WAY better for your body to take it's time breaking down carbs than to dump all that sugar in at one time. It leads to better insulin control and sugar maintenance. I'm not sure what you're main goals are, but insulin control and sugar maintenance for me is about health, not necessarily about weight loss. Excess sugar in the blood leads to inflammation, damage to the arteries and blood vessels which lead to plaque, etc. Yes, it can contribute to fat gain as well, but as the other posters have noted, it's a different fat gain than fructose.
Fructose, on the other hand, skips being broken down the traditional way and goes straight to the liver to be broken down. For years, diabetics used fructose because it didn't spike insulin levels, but it seems like long term use decreases insulin sensitivity, which is just as bad as regular sugar. In addition, the liver uses fructose to make triglycerides, which leads to bad cholesterol (if you believe in that kind of thing). Excess fructose leads to fatty liver and visceral (in the body around the organs = BAD) fat.
That doesn't mean that an occasional fruit is bad for you. One of the nice things about most fruits is that they have soluable fiber, which helps slow the absorption of the sugars, plus helps with gut flora (as opposed to insoluable fiber, which doesn't do anything positive - but that's another post for another time). If you have a banana and you feel fine and don't have a crash, then good for you. If you eat several bananas and a couple of oranges every day, you might be overdoing it.
Also, as a side note, insulin sensitivity is a good thing. A lot of people think "why would I want my insulin to put away the sugar into fat more effeciently?" The reason is that long term elevated blood sugar is way more damaging to your body than a short term fat storage. Also, not all of the blood sugars get deposited as fat. Your body uses insulin to get the nutrients and energy to the cells, it's just the excess that gets stored as fat. And if you're exercising, some of those sugars will be stored in the muscles, not the fat. I just thought I'd point that out.
on March 28, 2013
at 02:03 PM
Glucose and Fructose are not equal.
Two groups, same calories from glucose vs fructose. After 10 weeks, all gained three pounds but....
The fructose group gained a disproportionate amount of visceral fat, which increased by 14%
fructose group saw a worsening of blood glucose control and insulin sensitivity.
They also saw an increase in small, dense LDL particles and oxidized LDL
Liver synthesis of fat after meals increased by 75%, etc...
on March 28, 2013
at 02:00 PM
Why bother with fruits? Table sugar is readily available and less expensive. You can probably get a deal on HFCS, if you buy in bulk.
... okay, seriously now. Both sugary fruits and dense, starchy sources of carbohydrates like roots and tubers have their possible benefits and harms. Sadly, I can't give you an answer as to what will work for you, but it will be extremely unlikely that you function optimally on zero roots or tubers. You may require more sugary fruits than others, though.
For me, if I don't get adequate (read: a lot) of roots and tubers a day, I can't fuel my regular (and often strenuous) physical activity. I definitely like me my sugary fruits, though. I like my fatty fruits even more - yay avocados!
There are families of fruits that have both sugar and starch like winter squashes, as well as roots and tubers that are primarily sugar and not starch like beets. They may suit your situation better than super-dense starchy sources like cassava.
I just realized that HuntingBears specifically pointed out "bananas" as the fruit that makes them feel good, which is interesting. Bananas are a great example of a fruit that contains some sugar, but a lot of starch (and fiber). About a 4:2:1 ratio for those three items in a serving.
This makes me curious as to what they consider a "complex carbohydrate"? I know the definition can be broad, but usually it's "food items that contain a good amount of starch."
If grapes made them feel better (pretty much mainlining sugar with those), the implied premise in the question would be clearer.
on March 28, 2013
at 02:41 PM
According to this detailed explanation on how the metabolism of fructose and sucrose works, it seems that fructose stimulates appetite at hypothalamus level whereas sucrose tends to down-regulate it.
That could explain why starchy carbs are more satisfying and fructose by-products generate so much cravings.
That being said, I don't think that a little bit of natural occurring fructose in fruits should be of much concert since the benefits may far ought-weight the odds of fructose, but when you consider how much of this it is in artificially sweetened products, then the whole picture changes, I guess.