The harder you work for a meal, the better it tastes, according to a new study in mice.
When mice were given a choice between two foods — one food they had been made to work hard for, and another food they had acquired easily — they preferred the food that had been harder to get. And exertion made previously undesirable food tastier to the rodents, the researchers said.
While more work needs to be done to see if the finding applies to humans, it suggests low- calorie, perhaps unappetizing food, can be made to taste better if someone has to work hard for it, said study researcher Alexander Johnson of John Hopkins University in Baltimore.
This finding may have benefits for those on a diet, Johnson said, and it suggests a homemade meal that took hours to prepare may taste better than a frozen dinner that's just thrown in the microwave.
In the study, the researchers trained mice to push down levers to obtain food — the mice received either a sweet or starchy liquid. Next, the researchers slowly increased the amount of effort required to acquire one of the liquids. By the end of the experiment, the mice had to push down a lever 15 times to get the “high-effort” liquid, but just once to get the “low-effort” liquid.
Later, in a different cage, the mice were presented with both liquids and allowed to choose either one. The mice preferred to drink the liquid associated with their hard work — regardless of whether it was sweet or starchy — rather than the one they obtained without working up much of a sweat.
The fact that the mice showed this preference while in a different setting from the one in which they were trained suggests the high-effort food may have acquired a new, and better, taste for the rodents, the researchers said.
In a second experiment, the researchers repeated the experiment, but this time, they gave the mice a high-calorie liquid and a low-calorie one.
The mice consumed significantly more of the low-calorie liquid if they had been made to work hard for it during the experiment. This increase in consumption was not seen for the low-calorie solution if it was the “low-effort” food.
The mice also took more licks of the low-calorie “high-effort” food within the first minute of tasting, an indicator that it tasted better to the rodents.
The researchers speculated this apparent change in the mice's taste for low-calorie food has its roots in evolution — when food is scarce, and animals need to go to great lengths to find nourishment, having bland scraps taste gourmet would encourage the critters to chow down.
The study will be published Nov. 3 in the journal Proceedings of the Royal Society B.