Being apparently mildly overweight when you're an 11 year old girl is probably not a health problem, because, again, puberty.

That article indicates, from a single study, that being overweight without MetS brings a slightly higher risk of heart disease compared to non-overweight persons without MetS. While interesting, this hardly qualifies as being overweight = bad for your health.

Dismissing a study based on it being single is idiotic.

The study was based on 71 ,527 individuals, it is statistically significant.

http://www.ncbi.nlm.nih.gov/pubmed/24217719

Let me guess, you're obese?

> Dismissing a study based on it being single is idiotic.

I am not dismissing this study. It is interesting and has merit as a study.

> The study was based on 71 ,527 individuals, it is statistically significant.

I am not disputing the study or its methodology, only that drawing a final conclusion about weight and heart health from a single study is generally a bad idea. Meta analysis of studies on being overweight and obese (EDIT: by BMI category) have shown different conclusions on the impact to health. This is covered under that linked news story paragraph titled 'Mixed Results from Previous Studies'.

> Let me guess, you're obese?

Not at all, I'm not even overweight. (EDIT: By BMI, I don't meet those categories. BMI is a horrible metric).

A difference of 10^-100% is statistically significant with a large enough sample size. The question of actual significance is how relevant is the measured difference. Statistical significance asks how likely it is that the difference actually exists.