Now that you know the basics of insulin and blood sugar, we’re going to talk about a variation…a nice one. Turns out that when we exercise, we cause a fundamental shift in the way our muscles take in glucose. Which makes things much, much better.

Here’s how it works: The muscles still need some insulin to signal the GLUT4 receptors (the darling “buttercups” ) to come to the surface of the muscle cells. But they don’t need near as much. In fact, muscle contraction alone (exercise) causes a cascade of signals inside the cells that pushes the buttercups to the surface, allowing the muscles to take up glucose without any insulin at all. What’s more, muscles that are used to exercising become more “insulin sensitive”—essentially, they need less insulin overall. Your take-home message for the day: Go work out and we won’t have to cut your legs off!

The second message: Don’t drink your calories. There are two great reasons.

First, squeezing fruit and grinding up vegetables into “smoothies” breaks down the fiber. That is exactly what we do not want. In addition, liquids have a much lower “satiety factor” than solid food. You can drink a ton of cola, fruit juice or gin-and-tonics—with a ton of calories—and not feel full. Disaster!

Smoothies and juices are much in vogue these days, as are so-called sports drinks. Bad idea, especially the sports drinks, which you don’t need unless you’re planning to run a marathon or two. Eat real fruit and vegetables instead, and drink water. Your buttercups will thank you.