This time, it's not the calories

If you were told that two milkshakes had vast differences in calorie content, with the higher one being called “indulgent” and the other, “sensible,” which do you think will make you feel more satisfied? Obviously, it would be the one with the more calories. But is satisfaction purely about calories?   

The scenario I mentioned actually took place as an experiment that was published online last May 16 in the Journal Health Psychology. Indeed, the ones who were told they were drinking the “indulgent” milkshake felt more satisfied. But that was not the whole point of the science being tested here. If you were paying careful attention to the opening sentence of this column, I wrote “if you were told.” Yes, the 46 subjects who were given the two kinds of milkshakes were told the milkshakes had different calorie content but in fact, they had exactly the same calorie content - 380 calories. The scientists really wanted to know if the hormone ghrelin, responsible for making us feel both hunger pangs and having had enough, would also be affected by what we think and not by the actual calories we consume.    

Ghrelin is a hormone produced in our stomachs which makes us gain appetite while anticipating mealtime. Before we eat, we need calories so ghrelin rises and after a meal, ghrelin level drops. Seems like simple cause and effect, right? Nope. From this experiment where they check ghrelin from blood samples of the participants, the same calories caused ghrelin to drop after drinking the “indulgent” milkshake (supposedly 620 calories) and to stay flat after having the “sensible” milkshake (supposedly 140 calories). This means that the appetite for the ones who had the “sensible drink” remained even if they felt satiated when they drank the “indulgent” milkshake which had the same calories. It looks like how we perceive food determines ghrelin response, which in effect determines whether we feel full or not. The subjects also tasted the two kinds of milkshakes a week apart so they most likely could not directly compare the two.  

The findings revealed how perception, fed by words, could trick biology. This means that how “rich” you perceive your food determines how satiated you are. It clearly shows that a clear understanding of the foods we eat in terms of their nutritional and calorie content directly affects our health. This gives our minds even more power over our diets than we thought. Indeed, reality shows like the Big Loser and other diet shows focus on motivation and psychological support to the struggles of those trying to lose a lot of weight. But I think these shows could have added wisdom from these findings by also explaining that whatever is happening to our brains has to also affect our ghrelin levels to signal “fullness.” Unless the psychology sets this mechanism into play, the weight loss may not happen.

I think this finding also emphasizes the responsibility of food manufacturers to maybe think of sexier, more “indulgent” adjectives (or probably visuals) to describe their “healthy” products. It seems like “healthy” is just not wired in the same neural weave as the foods we find “satisfying.”

Satisfaction from food is not purely about calories. It is also about perception and based on this experiment, it is largely about perception. Perception of food is shaped by what we hear, see, feel, read about it. As we swim through the unparalleled feasts of images and words on food products especially in this digital age, I wish you understanding in your food journeys because clearly, the weight of perception could bear on your actual weight.

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