A small study (published in Pediatrics) shows that teenagers will overeat fast food regardless of visual cues or portion size.
The lead study author calls for "fundamental improvements in the nutritional quality of fast food".
What's interesting about this research is that it doesn't quite fit with the usual paradigms that blame visual cues for overeating.
The teenagers were offered a meal of nuggets, fries, and coke. Over three different days, the meal was presented in three different ways; all at once, split into four smaller portions, or allocated out over 1 hour.
Regardless of the presentation - the teens still consumed the same amount - 1300 calories.
So what is it about fast food?
I can clearly remember digging into buckets of KFC chicken in my teens. At the time I couldn't have cared less about nutrition. My "fast metabolism" seemed to cope with it all quite nicely.