Expected satiety is the amount of relief from hunger that is expected from a particular food. It is closely associated with expected satiation which refers to the immediate fullness (post meal) that a food is expected to generate.
Scientists have discovered that foods differ considerably in their expected satiety. One estimate in the United Kingdom suggested that there may be a six-fold difference in foods commonly consumed there, when they are compared calorie for calorie. [1] This range of variation is important because expected satiety is thought to be a good predictor of food choice and an excellent predictor of self-selected portion sizes. [2] Specifically, foods that have high expected satiety and high expected satiation tend to be selected in smaller portions (fewer calories). Therefore, they may be especially suited to diets that are designed to reduce energy intake.
Some researchers also suggest that expected satiety is an important mediator of energy intake. [3] [4] They argue that within-meal events (immediate post-ingestive feedback, e.g., gastric stretch) play a relatively minor role and that meal size is largely determined by decisions about portion size, before a meal begins. Consistent with this proposition, observational studies show that 'plate cleaning' is extremely common, [5] that humans tend to plan their meal size in advance, and that ad libitum eating is relatively rare. [6] [7]
Early approaches relied on rating scales. [8] [9] More recently, techniques have been developed that quantify expectations very precisely by comparing foods directly on a calorie-for-calorie basis. The first of these used a classical psychophysical approach based on a 'method of constant stimuli'. [10] Participants are shown a fixed 'standard' portion of food and this is compared against a different 'comparison' food. Over a series of trials the size of the comparison food is manipulated and participants are asked to pick the food that is expected to deliver greater satiety. At the end of the task a measure of 'expected satiety' is calculated. This relates to the number of calories of the comparison food that would be expected to deliver the same satiety as the fixed standard. A conceptually similar alternative is to use a 'method of adjustment'. Participants are shown a picture of a standard food next to a picture of a comparison food. Using specialist software, participants change the size of the comparison portion using keyboard responses. [11] Pictures are loaded with sufficient speed that the change in the comparison becomes 'animated.' Participants are told to match the comparison food until both are expected to deliver the same satiety. If the same standard is used then the expected satiety of different foods can be quantified and compared directly.
Expectations about the post-ingestive effects of a food are learned over time. [12] In particular, it would appear that the expected satiety and expected satiation of foods increases as they become familiar. [13] [14] [15]
Expectations are also thought to be governed by the orosensory characteristics of food. Even subtle changes to the flavor or texture of food can have a marked effect. [16] [17] Expected satiation may be higher in foods that have a higher protein content, and in those that require more chewing and that are eaten slowly. [18] [19] Remarkably, it also appears that the expected satiety and expected satiation of foods is influenced by their perceived weight. [20]
The effects of expected satiety and expected satiation appear to extend beyond meal planning. Several studies show that these expectations also influence the hunger (physiology) and fullness that is experienced after a meal has been consumed. [21] Product labelling and branding is likely to modify expected satiety. [22] Therefore, this kind of information has the potential to influence appetite directly. Together, these observations are consistent with emerging evidence that implicates hippocampal-dependent memory mechanisms in behavioural responses to food. [23] [24] [25]
Recent reviews [26] highlight opportunities to reformulate commercial food products to increase their expected satiety and expected satiation.
Dieting is the practice of eating food in a regulated way to decrease, maintain, or increase body weight, or to prevent and treat diseases such as diabetes and obesity. As weight loss depends on calorie intake, different kinds of calorie-reduced diets, such as those emphasising particular macronutrients, have been shown to be no more effective than one another. As weight regain is common, diet success is best predicted by long-term adherence. Regardless, the outcome of a diet can vary widely depending on the individual.
Eating is the ingestion of food. In the natural biological world, this is typically to provide a heterotrophic organism with energy and nutrients and to allow for growth. Animals and other heterotrophs must eat in order to survive — carnivores eat other animals, herbivores eat plants, omnivores consume a mixture of both plant and animal matter, and detritivores eat detritus. Fungi digest organic matter outside their bodies as opposed to animals that digest their food inside their bodies.
Appetite is the desire to eat food items, usually due to hunger. Appealing foods can stimulate appetite even when hunger is absent, although appetite can be greatly reduced by satiety. Appetite exists in all higher life-forms, and serves to regulate adequate energy intake to maintain metabolic needs. It is regulated by a close interplay between the digestive tract, adipose tissue and the brain. Appetite has a relationship with every individual's behavior. Appetitive behaviour also known as approach behaviour, and consummatory behaviour, are the only processes that involve energy intake, whereas all other behaviours affect the release of energy. When stressed, appetite levels may increase and result in an increase of food intake. Decreased desire to eat is termed anorexia, while polyphagia is increased eating. Dysregulation of appetite contributes to anorexia nervosa, bulimia nervosa, cachexia, overeating, and binge eating disorder.
Satiety is a state or condition of fullness gratified beyond the point of satisfaction, the opposite of hunger. Following satiation, satiety is a feeling of fullness lasting until the next meal. When food is present in the GI tract after a meal, satiety signals overrule hunger signals, but satiety slowly fades as hunger increases.
A serving size or portion size is the amount of a food or drink that is generally served.
A food craving is an intense desire to consume a specific food, and is different from normal hunger. It may or may not be related to specific hunger, the drive to consume particular nutrients that is well-studied in animals. In studies of food cravings, chocolate and chocolate confectioneries almost always top the list of foods people say they crave; this craving is referred to as chocoholism. The craving of non-food items as food is called pica.
Peptide YY (PYY) also known as peptide tyrosine tyrosine is a peptide that in humans is encoded by the PYY gene. Peptide YY is a short peptide released from cells in the ileum and colon in response to feeding. In the blood, gut, and other elements of periphery, PYY acts to reduce appetite; similarly, when injected directly into the central nervous system, PYY is also anorexigenic, i.e., it reduces appetite.
The insulin index of food represents how much it elevates the concentration of insulin in the blood during the two-hour period after the food is ingested. The index is similar to the glycemic index (GI) and glycemic load (GL), but rather than relying on blood glucose levels, the Insulin Index is based upon blood insulin levels. The Insulin Index represents a comparison of food portions with equal overall caloric content, while GI represents a comparison of portions with equal digestible carbohydrate content and the GL represents portions of a typical serving size for various foods. The Insulin Index can be more useful than either the glycemic index or the glycemic load because certain foods cause an insulin response despite there being no carbohydrates present, and some foods cause a disproportionate insulin response relative to their carbohydrate load.
Palatability is the hedonic reward provided by foods or fluids that are agreeable to the "palate", which often varies relative to the homeostatic satisfaction of nutritional, water, or energy needs. The palatability of a food or fluid, unlike its flavor or taste, varies with the state of an individual: it is lower after consumption and higher when deprived. It has increasingly been appreciated that this can create a hunger that is independent of homeostatic needs.
In biology, energy homeostasis, or the homeostatic control of energy balance, is a biological process that involves the coordinated homeostatic regulation of food intake and energy expenditure. The human brain, particularly the hypothalamus, plays a central role in regulating energy homeostasis and generating the sense of hunger by integrating a number of biochemical signals that transmit information about energy balance. Fifty percent of the energy from glucose metabolism is immediately converted to heat.
Fibre supplements are considered to be a form of a subgroup of functional dietary fibre, and in the United States are defined by the Institute of Medicine (IOM). According to the IOM, functional fibre "consists of isolated, non-digestible carbohydrates that have beneficial physiological effects in humans".
Hunger is a sensation that motivates the consumption of food. The sensation of hunger typically manifests after only a few hours without eating and is generally considered to be unpleasant. Satiety occurs between 5 and 20 minutes after eating. There are several theories about how the feeling of hunger arises. The desire to eat food, or appetite, is another sensation experienced with regards to eating.
Weight management refers to behaviors, techniques, and physiological processes that contribute to a person's ability to attain and maintain a healthy weight. Most weight management techniques encompass long-term lifestyle strategies that promote healthy eating and daily physical activity. Moreover, weight management involves developing meaningful ways to track weight over time and to identify ideal body weights for different individuals.
Research into food choice investigates how people select the food they eat. An interdisciplinary topic, food choice comprises psychological and sociological aspects, economic issues and sensory aspects.
Sensory specific satiety is a sensory hedonic phenomenon that refers to the declining satisfaction generated by the consumption of a certain type of food, and the consequent renewal in appetite resulting from the exposure to a new flavour or food. The phenomenon was first described in 1956 by the French physiologist Jacques Le Magnen. The term "sensory specific satiety" was coined in 1981 by Barbara J. Rolls and Edmund T. Rolls. The concept illustrates the role of physical stimuli in generating appetite and, more specifically, explains the significance of taste, or food flavour in relation to hunger. Besides conditioned satiety and alimentary alliesthesia, it is one of the three major phenomena of satiation. An Ingestive Classics paper on the topic has been written in conversation with Barbara J. Rolls
Conditioned satiety is one of the three known food-specific forms of suppression of appetite for food by effects of eating, along with alimentary alliesthesia and sensory-specific satiety. Conditioned satiety was first evidenced in 1955 in rats by the late French physiologist professor Jacques Le Magnen. The term was coined in 1972 by professor David Allenby Booth. Unlike the other two sorts of stimulus-specific satiety, this phenomenon is based on classical conditioning but is distinct from conditioned taste aversion (CTA) in its dependence on internal state towards the end of a meal.
Ingestive behaviors encompass all eating and drinking behaviors. These actions are influenced by physiological regulatory mechanisms; these mechanisms exist to control and establish homeostasis within the human body. Disruptions in these ingestive regulatory mechanisms can result in eating disorders such as obesity, anorexia, and bulimia.
Satiety value is the degree at which food gives a human the sense of food gratification, the exact contrast feeling of hunger. The concept of the Satiety Value and Satiety Index was developed by Australian researcher and doctor, Susanna Holt. Highest satiety value is expected when the food that remains in the stomach for a longer period produces greatest functional activity of the organ. Limiting the food intake after reaching the satiety value helps reduce obesity problems.
Hedonic hunger or hedonic hyperphagia is "the drive to eat to obtain pleasure in the absence of an energy deficit." Particular foods may have a high "hedonic rating" or individuals may have increased susceptibility to environmental food cues. Weight loss programs may aim to control or to compensate for hedonic hunger. Therapeutic interventions may influence hedonic eating behavior.
Hyperpalatable food (HPF) combines high levels of fat, sugar, sodium, or carbohydrates to trigger the brain's reward system, encouraging excessive eating. The concept of hyperpalatability is foundational to ultra-processed foods, which are usually engineered to have enjoyable qualities of sweetness, saltiness, or richness. Hyperpalatable foods can stimulate the release of metabolic, stress, and appetite hormones that play a role in cravings and may interfere with the body's ability to regulate appetite and satiety.