Friday, June 13, 2014

Food Reward Friday

This week's lucky "winner"... kettle corn!

Who doesn't like kettle corn, that sweet, crunchy treat?  And why not indulge-- it's just a whole grain with a little bit of sugar!

It's certainly all right to eat kettle corn from time to time, but there is a reason we find it so seductive.  Although it may appear light and fluffy, popcorn is actually quite calorie-dense.  This is because chewing expels the air in popcorn, leaving a small volume in the stomach that's not much greater than if you had simply eaten unpopped kernels.  This means that popcorn, like crackers and rice cakes, doesn't deliver very much satiety for the number of calories it contains, at least compared to water-rich foods like potatoes.

Calorie density is also one of the primary rewarding properties of food, which is one of the main reasons why we like popcorn so much.  Add a coating of sugar to it, or fake butter in the case of movie popcorn, and it becomes easy to overindulge.


raphi said...

How does the brain (or body? or both?) evaluate the caloric load of a food?

[to be specific: not the rewarding, palatable or satiation stemming from its consumption - its caloric load]

Stephan Guyenet said...

Hi raphi,

The digestive tract detects carbohydrate, fat, and protein, and sends a (to be identified) signal to the brain. This causes dopamine release in the ventral striatum (nucleus accumbens), which reinforces behaviors related to acquiring the food just eaten. The more calories, the more dopamine, the more reinforcement.

Reward and palatability are simply a function of reinforcement. The more reinforcing a food is, the more motivating and palatable it will become after repeated consumption.

Satiation/satiety are produced in response to nutrients in the small intestine as well, except in that case we know how the signal is relayed to the brain: the vagus nerve. There's also a component of stomach distension.

raphi said...

Hi Stephan,

Thanks for the paper - not a bad read!

“The more calories, the more dopamine, the more reinforcement.”

So don't we expect that the following 3 statements:

“The more [protein] calories, the more dopamine, the more reinforcement.” —>
“The more [carbs] calories, the more dopamine, the more reinforcement.” —>
“The more [fat] calories, the more dopamine, the more reinforcement.” —>

to represent different degrees & 'patterns' of feedback? With direct implications on behavior immediately relevant to caloric control?

The Ancestral Chemist said...

Reminds me of "healthy" homemade granola with steel-cut whole grains and almonds, coated in maple syrup and roasted. It has the calorie density of candy, along with a health halo and the implication that it can be eaten every day for breakfast.
In my opinion, grains are best cooked in water and with a side of raw/steamed vegetables.

aluchko said...

The stuff drenched in butter is obviously bad but I'd actually heard that plain popcorn can be reasonably satiating.

(though the healthiness might get oversold due to the counter-intuitiveness)

Charlie Currie said...

Oh...this hurts...

Robino said...

Can heavily buttered and salted movie popcorn be part of a healthy paleolithic diet? (I've never taken anthropology, so I'm not sure if our robust hunter-gatherer forefathers snacked in this manner..)

~MyGalSal~The "Bird Whisperer" said...

I have done much researching in hopes to find a plan "right" for me. I subscribe to Life Extension (A4M)read magazines and books. I wonder if it's overkill. I just came upon your blog and I am fascinated and will continue to read. Sal

Aegirsson said...

Who doesn't like kettle corn, that sweet, crunchy treat?

Me, hate those, always had.

Unknown said...

Dangerous stuff