Hello and welcome to Nutrition Facts. I'm your host, Dr. Michael Greger. Today we're going to explore smart nutrition choices based naturally on facts.

Have a history of high blood pressure in your family? How about heart disease, diabetes? There are foods we can eat that may not only help prevent many of these chronic diseases, but even stop them in their tracks.

Smoothies are one of the most requested topics, but for years there seemed to be little pertinent research. So, surprise when I check back to find hundreds of studies.

So, shall we drink them or not? I don't want you to ever do anything just because I or anyone else told you so. That's the problem with the field nutrition.

Everyone seems to listen to their respective gurus who can sometimes just make pronouncements from on high without explaining their reasoning.

Can you imagine that flying in any other field of science? It's not what he said or she said, it's what the best available balance of evidence bears out.

2 plus 2 equals 4, no matter what your favorite mathematician says. So, about smoothies, do they make us healthier? Do they cause weight gain? Here's the story.

Famous study in 2000 compared the impact of soda versus jelly beans that people add 28 extra spoonfuls of sugar to their daily diet in the form of jelly beans or soda pop.

Then they measured how many calories they ate over the rest of the day to see if their bodies would compensate for all that extra sugar.

So, even adding the jelly bean calories, they're reading pretty much the same number of calories before and after adding jelly beans to their diet.

But in the soda group, and despite all the added calories from the Kansas soda they were drinking every day, they kept eating about the same amount.

So, with the soda calories added in, no wonder they gained weight after a month of drinking soda.

Their bodies didn't seem to recognize the extra calories when they were in liquid form, so it didn't compensate for them by reducing their appetite so they'd be less stressed the day.

This lack of regulation may be used to advantage the researchers suggest if you want to get fat. But what if you don't?

If we drink a smoothie for breakfast instead of a solid meal, will our body think we skipped breakfast and make us so ravenous at lunch we eat more than we normally wouldn't end up getting it.

Okay, well first is the solid versus liquid calorie effect real.

So, the and jelly beans don't just differ by physical form, they have different ingredients.

That's a problem with a lot of these kinds of studies, they use dissimilar foods.

Soup, pureed blended soup, essentially a hot green smoothie of blended vegetables, is more satiating than the same veggies in solid form.

The same meal in liquid form was more filling than in solid form.

So, it can't be the chewing, in fact there doesn't appear to be a solid versus liquid effect at all since cold smoothies appear to be less filling but hot smoothies appear to be more filling.

So filling, that when people have soup as a first course, they eat so much less of the main course, that even when you add in the calories of the soup, they eat fewer calories overall.

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