Orexin is a neuropeptide that influences energy levels. Sugar reduces orexin levels, which makes us sleepy. Jonah Lehrer digests a new study finding that protein counters the inhibitory effects of sugar:
These experiments also document, at a biochemical level, why the modern American diet is such a catastrophic mess. The typical supermarket is filled with processed foods where the only relevant "nutrient" is some form of sweetener. (So-called "added sugars" – they are injected into food during manufacturing – now account for 16 percent of total caloric consumption. That’s 21.4 teaspoons of sugar and corn syrup every day.) While such snacks are unfailingly cheap and tasty, they also lead to sudden spikes in blood sugar and a reduction in orexin activity. We eat them for the energy boost, but the empty calories in these foods make us tired and sad instead. (There’s some suggestive evidence that chronically low levels of orexin can increase the likelihood of depression.)
(Image: What have you got in your head?, a two-part series of human brains made with food, by Italian artist Sara Asnaghi)
The Dish 