Confection Confusion: Interplay Between Diet, Taste, and Nutrition

Abstract

Although genetics shapes our sense of taste to prefer some foods over others, taste sensation is plastic and changes with age, disease state, and nutrition. We have known for decades that diet composition can influence the way we perceive foods, but many questions remain unanswered, particularly regarding the effects of chemosensory plasticity on feeding behavior. Here, we review recent evidence on the effects of high-nutrient diets, especially high dietary sugar, on sweet taste in vinegar flies, rodents, and humans, and discuss open questions about molecular and neural mechanisms and research priorities. We also consider ways in which diet-dependent chemosensory plasticity may influence food intake and play a role in the etiology of obesity and metabolic disease. Understanding the interplay between nutrition, taste sensation, and feeding will help us define the role of the food environment in mediating chronic disease and design better public health strategies to combat it.

Keywords: chemosensory plasticity; diet composition; molecular mechanisms; obesity; taste.

Figure I.. Comparative Anatomy of Taste in Mammals and Insects.

(A, A′) Dedicated organs for taste sensation are located on the tongues of mammals (A, rodents, left, and humans, right) and on the proboscis and other body parts, such as the legs, of insects (A′). (B, B′) Specialized cells express taste receptors in the taste organs. (B) In the mammalian tongue, three types of taste cell (light green, dark green, and blue) are organized into clusters called taste buds and contact nerve fibers projecting to the brain (magenta). In the insect, taste hair (sensilla) house three or four single-modality taste neurons (light green, dark green, blue, and yellow) that project to the SEZ. (C, C′) Brain structures for taste sensation, processing, and reward in mammals and insects, here shown is the Drosophila melanogaster brain. Abbreviations: AMMC, antennal mechanosensory and motor center; MB, mushroom body; NTS, nucleus of the solitary tract; PBN, parabrachial nucleus of the pons; SEZ, subesophageal zone; SLP/SIP/SMP, superior lateral/intermediate/medial protocerebrum.

Figure 1.

Consumption of high-sugar and high-fat foods reshapes taste sensation and preference in rodents, humans, and insects, although the strength of the evidence differs across these organisms. These changes could alter different aspects of food intake, such as compromising the nutritional evaluation of food, inhibiting sensory enhance satiation, or creating a reward deficit. Together, these alterations could bias selection towards some types of foods over others and promote food intake, creating a vicious, reinforcing cycle that, over time, leads to weight gain and increases the risk of metabolic disease.