A sequence of physiological processes occurs in the digestive system after food ingestion. Although a balanced diet is important for gut health and overall wellbeing, the individual pleasure dimension also matters.
Livovsky and colleagues looked at human data on factors that determine the digestive experience and sensations before, during and especially after a meal.
The physiological digestive response to food ingestion has been widely studied and it is known that it comprises three semi-sequential steps: cephalic, luminal, and post-absorptive. First, meal substrates are extracted by a process of digestion and absorption that start in the mouth and extend to the terminal ileum. Later, meal residues that do not get absorbed in the small intestine pass into the colon and activate the metabolism of the gut microbiota, which in turn can affect digestive function.
Foods can also induce sensations before, during and after food ingestion due to the gut’s ability to sense and respond to intraluminal meal-related stimuli. These sensations basically include:
- Anticipatory food reward responses before a meal (i.e., motivated craving of a desired meal): the most relevant factors that affects food sensation at this level are taste, flavor, and palatability.
- Taste perception or gustation during ingestion and swallowing: mastication, salivation, and tongue movement modifies the organoleptic properties of food and, thus, can affect the eater’s receptivity to a meal.
- Sensations that extend for a while after food ingestion.
Although the third group has been subject to limited study, these food ingestion-related sensations play an important role in the way different foods become acceptable to people, especially in the context of functional gut disorders.
The postprandial experience involves both homeostatic (i.e., satiety, hunger, and fullness) and hedonic sensations (i.e., postprandial mood and digestive well-being). And in that regard, the authors cited digestive function (suited processing), the characteristics of a meal (amount, palatability, composition), and the receptivity of the eater (i.e. the individual’s responsiveness, influenced by multiple conditioning factors) as the most important factors that influence the postprandial experience.
- Within digestive function, gastric accommodation and intestinal dysfunction and hypersensitivity have been involved the most in impairing postprandial sensations. Although dietary fat is a major culprit in gastrointestinal symptoms both in healthy people and in patients with functional gut disorders, the underlying mechanisms and major food triggers involved have not been completely characterized.
- Meal load (the amount and portions of ingested foods), palatability, and composition are the main—and most frequently studied—characteristics of a meal involved in postprandial sensations.
- An individual’s receptivity is the most variable factor that can affect food ingestion perception. This can be shaped by a wealth of constitutive (e.g., gender) and inducible factors (e.g., education). For instance, women tend to be more sensitive than men to the influence of eating schedule on the meal experience, thus women tolerate smaller meals than men.
To sum up, digestive function, a meal’s characteristics and an individual’s receptivity are major factors that are important when considering how humans respond to food ingestion. Without forgetting the importance of a balanced diet (in terms of both food group and nutrient composition), biological responses to food ingestion are worth considering as means of improving quality of life in the context of personalized diets and digestive well-being, in both healthy individuals and those with digestive symptoms.
This review article belongs to the special issue “Food and Diet for Gut Function and Dysfunction” in the peer reviewed open access journal Nutrients. This issue was instigated by the European Society of Neurogastroenterology and Motility, guest edited by Profs Fernando Azpiroz and Paul Enck, and made possible through an unrestricted educational grant from Danone.
Livovsky DM, Pribic T, Azpiroz F. Food, eating, and the gastrointestinal tract. Nutrients. 2020; 12(4), 986. doi: 10.3390/nu12040986.