From what I understand, there is somewhat of a threshold in terms of how much fructose can be digested in your gut vs requiring your liver to get involved. It depends on a lot of factors (body size obviously, your overall calorie intake, some genetic factors, etc), but in general of you're only consuming a few grams of fructose and it's buffered by fiber, you're probably not exceeding that threshold. Fruit fits that bill, unless you're being weird and consuming a whole lot of sugary fruit.
There is no real difference between eating food to which refined sugar has been added and eating sweet fruits. The sugar is not bound to anything and it is released in the fruit juice when the fruit is chewed, so it is not digested more slowly than when eating a sweetened cake with the same proportion of sugar (but the cakes are frequently made much sweeter than the fresh fruits).
The great danger that has been created by the availability of cheap refined sugar and similar sweeteners, like HFCS, is that it has become extremely easy to create food that has an unnaturally high concentration of sugar or fructose and that it has become extremely easy to eat an excessive amount of sugar per day.
Most cultivated fruits contain around 10% sugar, while a few are sweeter than that, with up to around 16% sugar, like grapes, fresh figs or fresh dates.
When eating only fresh fruits or defrozen fruits, it is unlikely to eat too much sugar, but it is still possible.
It is recommended that the daily intake of sugar should not exceed around 50 g (i.e. around 25 g fructose).
That corresponds to around 300 g of grapes, or around 500 g of apples or pears or blueberries (or most other fruits), so eating amounts less or equal with these every day should be safe.
On the other hand, a single chocolate might contain over 60 g of sugar. Most industrially-made food, including juices or yogurts or breakfast cereals, contains excessive amounts of sugar, so many people eat daily 100 to 200 g of sugar, or even more, without being aware of this.
When eating dried fruits or honey, it is also possible to eat too much sugar without a lot of effort, e.g. around 80 g of most dried fruits is enough to provide the maximum recommended daily intake of sugar.
> There is no real difference between eating food to which refined sugar has been added and eating sweet fruits.
Yeah, I've heard people say this, but I can tell a big difference between people who eat a lot of fruit and people who eat a lot of processed sugar.
It's right up there with saying eating an avocado is going to make you fat because of all the calories it has so you should eat a hamburger with half the calories instead.
The fresh sweet fruits have a relatively low sugar content, so when eating them you will usually have enough before eating too much sugar, e.g. if you eat a half of kilogram (a pound) of fresh fruits each day that is still OK.
When pure sugar is added to food, most people, and especially most industrial producers, add far too much sugar, so it becomes very easy to eat too much sugar each day, while eating just a small amount of sweetened food, which does not cause satiety.
The only difference between sweet fruits and sweetened food is in the quantity of sugar, not in its quality.
If one eats, for example, 2 kilograms of sweet fruits each day, then that would still cause health problems eventually, even without any added sugar, like in the geese traditionally fed with figs, to make foie gras. The effect of eating food with too much sugar, which destroys the liver, has been well known for thousands of years, even before pure sugar became known in Europe.
If sweetened food is eaten in a very small quantity per day, it does not have any other effect than eating sweet fruits.
