Study leader Sunil Kochhar and colleagues studied 11 volunteers who classified themselves as 'chocolate desiring' and 11 volunteers who were 'chocolate indifferent.'
In a controlled clinical study, each subject — all men — ate chocolate or placebo over a five day period while their blood and urine samples were analyzed.
The researchers noted that 'chocolate lovers' had a hallmark metabolic profile that involved low levels of LDL-cholesterol (so-called 'bad' cholesterol) and marginally elevated levels of albumin, a beneficial protein.
What's more, the team found that chocolate lovers expressed this profile even when they ate no chocolate, and that the activity of the gut microbes in the chocolate lovers was also distinctively different from the other subjects.
"Our study shows that food preferences, including chocolate, might be programmed or imprinted into our metabolic system in such a way that the body becomes attuned to a particular diet," says Kochhar, a scientist with Nestlé Research Center in Switzerland.
"We know that some people can eat a diet that is high in steak and carbs and generally remain healthy, while the same food in others is unhealthy.
"Knowing one's metabolic profile could open-the-door to dietary or nutritional interventions that are customized to your type so that your metabolism can be nudged to a healthier status."
The study lends further evidence that metabolic status and food preferences can vary from person to person.
The researchers now plan to include women in future clinical trials on metabolic responses to chocolate to determine if there is a gender-specific response to the treat.
Women were not included in the current study in order to avoid any metabolic variations linked to the menstrual cycle, which has been shown in studies by others to influence metabolic differences.
The study is scheduled for publication in the Nov. 2 issue of American Chemical Society's Journal of Proteome Research, a monthly publication