Yeah, but in this case it may be a relevant indicator. It's most likely that the people that eat breakfast do it either because they want to care for their body and/or because they are following societal norms. So, the people that skip it are rebels. I'd also guess that the people that skip breakfast are more likely to smoke too.
The really said part of this article is this though:
"The survey also found that nearly 40 per cent of married couples had not had sex in more than a month. Respondents said they were too tired because of work or found sex to be a pain, according to the study. "
Maybe it's the parents...more attentive parents would push their kids to have breakfast and might be more active in their lives....
French Fellatio with Sausage and real Maple Syrup. The breakfast of champions,
So what time do they lose their virginity?
I am guessing that it must be by lunch time, otherwise none of this makes any sense. 
Big old fat 
.
ironix
Correlation != Causation.