I'd like to eat a light sweedessert like fruit jelly, because I've just had a heavysome ramen asfor lunch, which is really filling.

"Dessert" is more commonly used along with "light" instead of "sweet(s)". Also, I would say "filling" is more appropriate than "heavy".

The other day, I checked my vascular age and it's not good, soreat. That is why I need to takeat more healthyful foods, like vegetables or fruits.

Two points:
1. "I checked my vascular age" assumes you did the relevant examination yourself; if you had a doctor do it for you, you should instead write "I had my vascular age checked (by a doctor)..."
2. This is perhaps a losing battle at this point considering the relative popularity of the expression, but I am ready to defend this particular hill; bodies are "healthy", while food is "healthful".

I definitely prefer fruits, but Tthey have been getting more expensive lately.

I'd like to eat a lighsomething a little / a bit sweet like fruit jelly, because I've just had a heavy ramen asfor lunch.

The other day, I checked my vascular age and it's not good, so I need to takeeat (start eating) healthy foods like vegetables or fruits.

I definitely prefer fruits but Tthey have been getting more expensive lately.

Very good.

I'd like to eat a light sweet, like fruit jelly, because I've just had asome heavy ramen asfor lunch.

Jelly, if you're speaking about the kind that is standard for us and is the spreadable sort coming from a jar, isn't something you'd eat alone. So you would mention what you are eating the jelly with: Jelly and bread, jelly and cake, etc. However, it's possible you are describing a different treat I'm not familiar with.

The other day, I checked my vascular age, and it's not good, s. So I need to takeat more healthy foods, like vegetables orand fruits.

"Take" isn't used in terms of eating, or in terms of buying things at the store

I definitely prefer fruits, but Tthey have been getting more expensive lately.

I'd like to eat a light sweet, like fruit jelly, because I've just had a heavy ramen asfor lunch.

Extra comma needed here to make "like fruit jelly" into a subordinate clause

The other day, I checked my vascular age and it's not good, so I need to takeeat healthy foods like vegetables or fruits.

"Take" doesn't really make sense in this context. You can "take medicine" but in this context "eat" makes the most sense.
"vegetables or fruits" isn't wrong, but I find "fruits or vegetables" flows more naturally

I definitely prefer fruits, but Tthey have been getting more expensive lately.

No capital needed for "they"