Why Sugar Makes Us Tired and What You Can Do About it !

 

Those sugar highs you think you get are likely a figment of your imagination. In reality, they're more like sugar sedatives. Jonah Lehrer, writing for Wired, points out that orexin—a brain chemical that keeps you feeling awake—is inhibited when you consume sugar. Fortunately, there's a fix.
Lehrer points out a study looking at the effects of different foods on orexin that discovered that while sugar lowered orexin levels in the brain (which creates a tired feeling) and protein excited the orexin cells into production mode (generating a feeling of alertness):

The last sequence of experiments explored the impact of different nutrient combinations on the orexin system. Although the scientists assumed that the inhibitory presence of glucose would more than compensate for the excitatory influence of protein, that hypothesis turned out be incorrect. Instead, consuming even a little protein canceled out the curse of sugar, especially when the foods were consumed simultaneously. (When the animals ate protein first, and then swallowed a chaser of glucose, orexin neurons still showed a decrease in activity. So make sure your dessert has some protein in it.)

This research is just further evidence suggesting that what we eat isn't about calories in and calories out. The content of our meals really matters. Furthermore, it's worth noting that sugar isn't a great substance regardless of the presence of protein.

Studies have taken a close look at sugar and how fructose isn't digested like normal food.

You're better off staying away from the stuff in general, but at least you can deter some of the negative effects by including a little protein in the mix.