As a child I guzzled sweets and fizzy pop. As I’ve got older I’ve gone off sweet foods, I much prefer savoury and bitter flavours nowadays. I drink diet cola but that’s the only sweet thing I enjoy most of the time. Does this change in tastes happen to everyone or is it individual change? What is the reason if any for the change?
It didn’t happen to me. I still have as sweet a tooth as I had as a child, and I’m in my 50s now. I wish it weren’t so, it makes weight control more difficult.
In my experience it can go both ways.
As my father aged, he gradually lost his sense of taste. During this period, of course, he compensated by requiring foods with more extreme flavors, regardless of whether they were sweet, spicy, etc.
I am now 63, and I’ve noticed that I want ***less ***extreme flavors. Sweet food like candy tastes way too sweet for me. I can’t tolerate extremely spicy or salty food the way I used to. I’m more into subtle seasonings.
Oh, I wish my mother (70 years old) would lose her sweet tooth, because I’m sure she’s attempting suicide by an overdose of chocolate chip cookies. 
No quote for this, but I’ve seen TV health programs claim that children actually like salty better but we teach them that sweet is good. The same said that in general, as people age and lose some of their sense of taste, they go for more-extreme tastes.
There’s definitely a cultural component: Spanish cooking doesn’t go much for hot dishes (we have guindillas and other forms of pepper, but nothing like what you get in Mexico or India), so most Spaniards need a conscious effort to get used to curry and similar inventions. I strongly dis-recommend trying any Mexican restaurant in Spain: watered-down doesn’t begin to describe it, but it’s because otherwise they wouldn’t be able to sell a tapa.
Yes, this except I’m a little older.
Anecdotal only. I work in a nursing home and when dementia people won’t eat their main course, they will often eat their dessert.