"[INSERT FOOD] for some people is unhealthy at any amount" is what should be always said. People then have to determine what those foods and level of foods are, it could be accumulative as well - where too much of a few different foods may be too irritating to your system.
Probably not the answer you’re expecting but damn I love avocado toast, pizza, naan, french toast, burger, croissants and any form of bread.
I don’t care if I die a few years early, I love bread.
Have you ever felt tired and out of whack after eating fruit? Have you seen the size of people on a fruitarian diet? (Spoiler, they loose a dangerous amount of weight). You don't get fat by eating fruit and having an occasional soda, you get fat by eating lots of pasta and bread.
I challenge you to gain weight on a diet of steak and orange juice.
If you get a 'crash', it's because your blood sugar level is too low. One way that this can happen is by eating refined (simple) carbs - aka sugars. The release of sugar into the blood-stream is fast, leading to a large release of insulin from the pancreas, which then drives the sugar in the blood stream into the cells, giving a consequent drop in blood sugar. Unless you then replenish the blood sugar you get a 'crash'. Far better is to eat in a way that doesn't give you that spike of blood sugar, so that the insulin response is less.
> Have you ever felt tired and out of whack after eating fruit?
No, not that I can think of specifically related to fruit.
> Have you seen the size of people on a fruitarian diet? (Spoiler, they loose a dangerous amount of weight).
Not sure what an anecdotal observation of people on a weird diet proves.
> You don't get fat by eating fruit
No-one said you did. And (spoiler) not all sugars are equal. Eating a piece of fruit is not the same as eating a piece of candy, just because they both contain (some wort of) sugar.
> you get fat by eating lots of pasta and bread.
(This is a weird and partly incorrect statement, but...) Who said this was about getting fat? There can be negative health effects from what someone eats, aside from weight gain.
> I challenge you to gain weight on a diet of steak and orange juice.
Not sure what this weird unbalanced diet would prove either?
Refined carbs are complex carbs not simple sugars. Fructose in fruit is a simple sugar, sucrose (table sugar) is a simple sugar. Bread, pasta and anything containing wheat is a complex refined carb. There are refined sugars however like high fructose corn syrup which btw doesn't have the same composition as normal fructose, hence the deleterious effects. Refined carbs cause insulin problems more than fructose from fruit, that's why you never feel bad after eating fruit but you can get a food coma after eating too much pasta. The reason is because your body releases the insulin before the complex carbs are fully broken down lowering your blood sugar to below normal levels. With fructose because it is so bioavailable your insulin and blood sugar spike at the same time, in sync, resulting in normal blood sugar levels and a stable mood and energy level. When you start eating cake is where you get into trouble because it contains, guess what... refined carbs in the form of flour. That's why you feel just as bad after eating a lot of bread as a lot of cake despite one having a lot more sucrose. Sucrose is fairly similar to fructose. It's the not sucrose that's the problem, it's the complex carbs.
>Not sure what an anecdotal observation of people on a weird diet proves.
These people pride themselves on eating 3000+ calories a day and are dangerously skinny. What I'm saying is you can't get fat eating just fruit. These people are also incredibly unhealthy and I wouldn't recommend anyone eats like that but I think it does prove the point that the sugar in fruit is not the same as normal sugar.
I also don't buy the cartoonishly simplistic claim that "coca-cola is unhealthy". Does it cause obsesity? It doesn't "cause obsesity" in the same sense that ingesting more calories than you spend causes obsesity: It's not the coca-cola or the sugar by themselves.