Fatty diets may desensitize us to the taste of fat, study suggests

06 Jun 2018 --- People who consume a high-fat diet may, in turn, eat more fatty foods as they become desensitized to its taste, a study has found. The study, published in The American Journal of Clinical Nutrition, used twins to examine how individuals may vary when following either a high-fat or low-fat diet. The diets altered the fat taste sensitivity of the participants and highlighted the importance of the environment for weight maintenance.

“We have previously linked fat taste sensitivity with satiety or fullness in that those who are more sensitive to fat consume less energy. This study revealed that diet is the determining factor in establishing fat taste sensitivity, so if you consume a high-fat diet for a period (maybe as little as two weeks, although this study was an 8 week intervention) your body’s nutrient sensing mechanisms (taste receptors) are decreased,” Russell Keast, Ph.D., Professor at the Center for Advanced Sensory Science/School of Exercise and Nutrition Sciences at Deakin University and author of the study tells NutritionInsight.

The study included 44 pairs of twins and each twin within a pair were randomly allocated to an eight-week low-fat or high-fat diet. The aim was to assess the effect of the diet on fatty acid taste threshold (FATT). The low-fat diet consisted of about 20 percent of calories from fat, compared to 35 percent in the high-fat group.

The results showed that twins who ate a high-fat diet for eight weeks lost their ability to identify fatty acids in liquid. On the other hand, their siblings who consumed a lower fat diet were able to detect lower concentrations of fatty acids after one month, as well as at the end of the study period.

These findings indicate that eating a high-fat diet may decrease satiation, creating a vicious circle model where individuals will need to eat more and more fatty foods to feel satiated.

“We speculate that this is an evolutionary advantage as in times when fat was plentiful it allows excess consumption of energy. In times when fat was scarce, receptors are enhanced, your sensitivity is increased and you feel fuller with less energy – so you would not be walking around really hungry all the time,” adds Keast.

Although this particular study did not assess the type of fat ingested in the diet in this intervention, a previous study cited by researchers did show that polyunsaturated fats are more activating (perceived at lower concentrations) than monounsaturated or saturated fats. 

Obesity: genes vs. environment
The study adds valuable data to the debate around the role of genes vs. environment for obesity.

NutritionInsight recently reported on findings from King’s College London that uncovered the role the gut plays in processing and distributing visceral fat on the body. The research demonstrates that the response of our gut microbes to our diets can directly affect obesity. Significantly, this means that they are primarily controlled by what we eat rather than our genes, paving the way for personalized treatments that utilize gut enhancing fibers or probiotics for obesity and other chronic diseases. 

Arguably, findings such as these could aid consumer education about what types of food to eat and how much fat to consume. The Dietary Guidelines for Americans suggest that fat should account for about 20-35 percent of daily calories; therefore a very low-fat diet is not desirable. However, consumer trends do show that consumers are more educated about healthy fats than ever before.