Looks like a good essay! I've commented below on a few grammar errors, and provided direction to help you correct them.
The proportion of obese children have seen to increased
You can simplify this sentence and fix the tense by saying: "obese children has increased".
, one of this is unbalanced diet.
This has a comma splice, which means you should either strengthen the conjunction (", and one") or have it as its own sentence. You might also want to change "this" to "them".
meals which is more than what they actually needed and most of the time unhealthy
You could clarify this sentence with a little tweaking, like, "more meals than they actually need, many of which are unhealthy".
One of the major drawbacks of this problem is topics concerning the child well-being.
You could simply this sentence by saying, "One of the major drawbacks of this problem is children's well-being."
Should be "their" cholesterol.
Should be plural - "diseases".
sons or daughters attitude
Don't forget apostrophes - "sons' or daughters' attitude".
where they like a couch potato
You can clarify this sentence by removing "where they" - "like a couch potato"
should be manage seriously
This should be in past tense, so "should be managed seriously"
Good luck editing! You're nearly there.