An apple a day makes you fat…
An apple a day keeps the doctor away…
Over the past several years there has been a lot of debate around fruit and its role in body weight and overall health.
The crux of the argument lies in the sugar that is found in fruit, fructose. But more specifically high-fructose corn syrup.
So today we are going to cover fructose and help reduce the confusion around it.
1) Fructose is a fruit sugar, but gets metabolized a bit differently
Fructose is a sugar that is found in fruit. Similar to glucose and lactose, but is just slightly different. This difference means that your body processes it a bit differently than other sugars. Specifically, almost all fructose metabolism occurs in your liver.
2) Fructose is part of table sugar, high-fructose corn-syrup is just a slightly different form of table sugar.
Regular sugar is called sucrose, which is 50% glucose and 50% fructose. High-fructose corn-syrup is 45% glucose and 55% fructose. So if we take 100 grams of regular sugar, we have 50 grams of fructose. If we take 100 grams of high-fructose corn syrup, we have 55 grams of fructose.
3) When consumed, your body can’t store fructose so you process it, and most of it just gets used for energy pretty quickly.
We often hear that fructose gets converted to fat in the liver, but it turns out that is a very small percentage of the fate of fructose. In fact, <1% of fructose gets turned into fat. Here is what happens to the rest of it.
4) It turns out that <100 grams of fructose per day has no real negative health effects.
There have been hundreds of studies on fructose at all ranges of intake (from <10 grams to >300 grams) and it turns out that we know where the threshold of potential health problems are.
That number looks to be around 100 grams.
Fructose consumption at moderate levels of intake do not adversely effect body weight or blood chemistry based on the current data.
Obscenely high levels of intake (>150 grams per day) may have undesirable health effects.
Together, these two concepts essentially tell us:
1) that we can consume 3-4 servings of fruit a day, if we so desire, with no health consequences
2) that we should not mainline 2 liters of Mountain Dew or consume large amounts of fructose or HFCS.