The sweets are out and the champagne's flowing but you can't possibly have another iota of sugar or alcohol.
Before you congratulate yourself on your willpower, you might want to save some praise for your liver, because two new studies released today, on Christmas, show the first evidence of a liver-derived hormone that specifically regulates intake of sugars and alcohol.
This hormone has major potential for its ability to prevent overconsumption of sugar, which could be harnessed for the diet and wellness market but so far, its effect has only been studied in mice and primates.
The first study in primates showed the hormone -- called FGF21 -- suppressed the consumption of sweets with just one dose.
"We never imagined that a circulating, liver-derived factor would exist whose function is to control sweet appetite," University of Copenhagen co-senior author Matthew Gillum said.
"We are very excited about investigating this hormonal pathway further."
University of Texas Southwestern Medical Center senior author Steven A. Kliewer cautioned there were other factors at play when it came to cravings.
"While at first blush it would seem that this FGF21-regulated pathway could be a panacea for suppressing sugar and alcohol consumption, it's important to keep in mind that these reward behaviors are closely tied to mood, and so additional studies to determine if FGF21 causes depression are certainly warranted," Kliewer said.
The second study of the hormone in mice found it entered the bloodstream and selectively suppressed sugar appetite. University of Iowa senior author Matthew Potthoff said similar hormones could be applicable to different cravings.
"We would like to see if additional hormones exist to regulate appetite for specific macronutrients like fat and protein, comparable to the effects of FGF21 on carbohydrate intake," Potthoff said.
"If so, how do those signals intertwine to regulate the neural sensing of different macronutrients?"