If you've walked into a trendy coffee shop lately, like one of our studio audience members did in NYC, you might have noticed a new popular milk option — oat milk! (No, seriously, it's everywhere. Even Bob Harper told us he switched the almond milk in his morning coffee to oat milk last year.)

Well, what's all the fuss about?

Physician and best-selling author Dr. Ian Smith has the scoop.

"This milk has more protein than any non-dairy milk," the doc explains, "except for soy."

"[It's] a little lower in calories," he continues, "and [the] beauty is that the oat is a whole grain, so [it has] all those phytonutrients — fiber, protein, B vitamins. It's all in here."

Plus, you can make it yourself at home instead of buying it, Dr. Ian says!

First, the doc starts with either one part whole oats or steel cut oats. Then, he adds two parts water and lets the mixture soak for at least eight hours, but ideally overnight.

After it soaks, put the mixture into your blender and blend for 30 to 45 seconds. Pour the blended mixture into a strainer or a cheesecloth, and voilà, you have oat milk.

You can store your homemade oat milk in the fridge for about five days, Dr. Ian says.

And as he puts it, it tastes like liquid oatmeal. (We're not mad about that!)

Always check with your doctor before you make dietary changes.