To the girl that said: 'I can't believe you're putting refined and fruit sugar on the same level' (which I didn't) and the 25+ people that liked her comment.

Disclaimer: for the sake of keeping this somewhat comprehensible I'm only talking about sucrose, glucose and fructose, but feel free to do some research on your own about galactose and other disaccharides.

Lately everyone's going on a very questionable sugar diet that avoids the consumption of 'industrial' sugar and supports the consumption of 'natural' sugar instead.

I've got a few problems with this and here's why.

First of all, what do people mean when they say 'industrial' or 'natural' sugar.

'Industrial' sugar usually refers to refined sugar (in my experience that is, a lot of US Americans mean high fructose corn syrup though, which is a whole other story), which just means that the molasses has been removed from the raw sugar you get from sugarcane or sugar beet. The molasses are removed to whiten the sugar and to get rid of its strong taste (this only concerns the sugar beet, sugarcane can technically be enjoyed without being refined first). Sometimes heavy syrup is added first to wash away the outer coating, but this is uncommon today. However, the sugar is dissolved to make a syrup itself first. Phosphoric acid and calcium hydroxide are then added to clarify the sugar. The end product of those two added chemicals, calcium phosphate, is removed again later on. The sugar is whitened by being filtered through activated carbon or ion-exchange resin.
Although chemicals are involved in this process (duh, because literally everything is chemicals, just keep that in mind the next time someone talks about those unnatural chemicals added to our food) the sugar basically stays the same except that it's now clean and in most cases white. If u wanna call that unnatural and rather eat raw sugar from sugarcanes and beets straight from that dirty dirty ground, u do u, pal, u do u.

Now for that 'natural' sugar. What people mean by that is fruit sugar. Depending on where you get your fruit no other chemicals are used to clean or whiten fruits (let's just ignore all those pesticides, shall we?). Here's the first problem: some people mistake fruit sugar and unrefined sugar for the same thing. And, yes, technically fruit sugar is unrefined but more common than not unrefined sugar refers to sugar from sugarcane and beet that, guess what, hasn't been refined yet.

Glad we got that covered. Now, let's get into the reason you're all here for: Is fruit sugar healthier than refined sugar? Short answer: No. If you're one of those people that blindly trust everything they read online or in an article once, you can leave now. (Or only read the conveniently bold words.)

For everyone else: Here's the long answer.
(Quick side note: A popular youtuber once seriously planned to eat more fruit instead of refined sugar to help with her teeth problems (mainly cavities). Spoiler alert: the naturally occuring acid in fruits will destroy your teeth very effectively (especially if you tend to get cavaties to begin with.))
Most sources (mainly sketchy so-called 'medical' websites and online diet magazines) always talk about fructose vs. glucose. Here's the catch though: *looksbothwaysandwhispers* refined sugar consists of both fructose and glucose (pretty much 50/50). *waitsforgaspingtostop* Shocking, right? Fruits only contain fructose (naturally that is). So, what's so bad about glucose?

Healthy humans can completely break down glucose. This process is our main energy source (which is why we can't live without sugar). However, if you consume more glucose than is needed - and let's be honest, we all do - it is turned into fat. That's why so many people try to cut out sugar. And to some extend that is surely beneficial. But most of those people wanna cut it out completely, which - as stated previously - not such a great idea. Too little glucose = less energy, more tired, less concentration etc.; too much glucose = fat. (I'm not cherry-picking here, this is literally all I found about the health consequences of glucose.)

Fructose is much harder to digest. The process takes longer and uses up energy. It cannot be broken down completely either, which is why especially children often get diarrhea after eating too much fruit. Also, about one third of all humans at least occassionally (if not always) suffer from fructose intolerance. And when an intolerance to absorb something occurs it usually means we weren't meant to eat that (thousands of years ago everyone became lactose intolerant as one got older cause milk was only meant to be consumed by lil' babes), maybe this is why the apple was forbidden... but I digress. Fructose doesn't increase your blood sugar count as fast as glucose but studies suggest that it increases the risk of a too high blood pressure and can lead to obesity. Reason being that your body is much more likely to turn fructose into fat than is the case with glucose. Furthermore it increases the fatty acid synthesis (basically = fat) of other food and doesn't cause insulin secretion, which is one of those chemicals that gives you a feeling of saturation. Little amounts of fructose do increase glucose tolerance, which is really helpful if you suffer from diabetes type II. But it also increases insulin resistance which results in a higher risk of heart diseases. That's not even all though, fructose also increases the risk of liver diseases and gout (study proving this tested over 40000 men but no women). All those risks only occur if you eat too much fructose of course but since many many foods now contain fructose or even worse high fructose corn sryup instead of that bad bad glucose, pretty much everyone consumes too much fructose.

So, fructose, not that great after all. Glucose, also not that great if consumed in masses but still a bit better. All in all, here's what you should always do: consume as much as needed (both fructose and glucose) but don't go overboard and you'll be fine (unless you get other diseases that is, food can't save you from everything).

Some more disclaimers: As is always the case with science and most other things in life: there's plenty more detail and this is only what we know so far. But that's our best bet. Also, yes, I mainly got my information from Wikipedia but if you think about it for a bit, most of this makes sense and gets supported by other sources too. Also also, yes, most of those health consequences are only supported by studies (duh) and studies are... well, complicated. But I've taken a look at every single one of them (well, excerpts, since a lot of studies aren't online in full) and most of them seem to be well done considering amount and diversity of test objects and medical research (institutes that performed those studies seem reliable too, e.g. Bundesinstitut für Risikobewertung). There's one (Elizabeth et al) I wouldn't trust since they only tested six persons but its results are supported by larger studies (with over a thousand participants).
As per usual: do your own research and decide for yourself which sources you wanna trust. Or just quote some random article you found on a sketchy website but of course you only read the bold words completely out-of-context and it included a lot of technical terms and you don't have any idea what those mean but whatever, you'll just make up your own meaning and never change your mind about the subject ever again until the next sketchy article comes along.

Sources (most sources are in German but most are Wikipedia too so easily translated):
Steps of sugar refinery
Definition of molasses
Not a source but: English article about caries and sugars
Absorption of glucose, its health consequences and chemical composition of sucrose
Absorption of fructose and its health consequences
English one provided number of people with fructose intolerance
Definition of fatty acid synthesis