Improving weight loss RCTs. Measuring the step weight change from a sustained change in frequency of a particular eating or exercise pattern.

The public's trust in the science of avoiding unhealthy weight depends on a radical reform of the design and execution of weight loss programmes and their clinical trials. This Perspective reiterates the longstanding argument for measuring the effectiveness of each component of an intervention on obesity. Body energy content change results from a difference in rates between input and output. These rates are determined by the frequencies of specific patterns of dietary behaviour, physical activity and thermal comfort, plus the cost of resting metabolism. Since fat-free mass changes alongside fat mass, the amount of change in weight from a change in the frequency of a behaviour pattern comes to an asymptote. That step change in weight per unit of behaviour change is measured by regression from the change in frequency of the behaviour that has been maintained from baseline to follow-up. For hard evidence, weight loss programme participants' own words must be used to specify behaviour. In RCTs of multiple-component programmes, sequences of the behaviour patterns to be changed are randomised among groups. The resulting evidence on effective slimming practices can be delivered directly into therapeutic services and public health interventions for the culture investigated.

How did that individual make that perceptual decision?

Suboptimality of decision making needs no explanation. High-level accounts of suboptimality in diverse tasks cannot add up to a mechanistic theory of perceptual decision making. Mental processes operate on the contents of information brought by the experimenter and the participant to the task, not on the amount of information in the stimuli without regard to physical and social context.

Multisensory control of ingestive movements and the myth of food addiction in obesity.

Some individuals have a neurogenetic vulnerability to developing strong facilitation of ingestive movements by learned configurations of biosocial stimuli. Condemning food as addictive is mere polemic, ignoring the contextualised sensory control of the mastication of each mouthful. To beat obesity, the least fattening of widely recognised eating patterns needs to be measured and supported.

Meals described as healthy or unhealthy match public health education in England.

Dietary guidelines for the general public aim to lower the incidence of nutrition-related diseases by influencing habitual food choices. Yet little is known about how well the guidelines are matched by the actual practices that people regard as healthy or unhealthy. In the present study, British residents were asked in a cognitive interview to write a description of an occasion when either they ate in an unhealthy way or the eating was healthy. The reported foods and drinks, as well as sort of occasion, location, people present and time of day, were categorised by verbal and semantic similarities. The number of mentions of terms in each category was then contrasted between groups in exact probability tests. Perceived unhealthy and healthy eating occasions differed reliably in the sorts of foods and the contexts reported. There was also full agreement with the national guidelines on eating plenty of fruit and vegetables, eating small amounts of foods and drinks high in fat and/or sugar, drinking plenty of water, and cutting down on alcohol. There was a tendency to regard choices of bread, rice, potatoes, pasta and other starchy foods as healthy. Reported healthy and unhealthy eating did not differ in incidences of meat, fish, eggs, beans and other non-dairy sources of protein or of dairy foods and milk. These results indicate that operationally clear recommendations by health professionals are well understood in this culture but members of the public do not make clear distinctions in the case of foods that can be included in moderate amounts in a healthy diet.

Configuring of extero- and interoceptive senses in actions on food.

This paper reviews all the published evidence on the theory that the act of selecting a piece of food or drink structurally coordinates quantitative information across several sensory modalities. The existing data show that the momentary disposition to consume the item is strengthened or weakened by learnt configurations of stimuli perceived through both exteroceptive and interoceptive senses. The observed configural structure of performance shows that the multimodal stimuli are interacting perceptually, rather than merely combining quantities of information from the senses into the observed response.

Interactions between facial emotion and identity in face processing: evidence based on redundancy gains.

Interactions between the processing of emotion expression and form-based information from faces (facial identity) were investigated using the redundant-target paradigm, in which we specifically tested whether identity and emotional expression are integrated in a superadditive manner (Miller, Cognitive Psychology 14:247-279, 1982). In Experiments 1 and 2, participants performed emotion and face identity judgments on faces with sad or angry emotional expressions. Responses to redundant targets were faster than responses to either single target when a universal emotion was conveyed, and performance violated the predictions from a model assuming independent processing of emotion and face identity. Experiment 4 showed that these effects were not modulated by varying interstimulus and nontarget contingencies, and Experiment 5 demonstrated that the redundancy gains were eliminated when faces were inverted. Taken together, these results suggest that the identification of emotion and facial identity interact in face processing.

Food after deprivation rewards the earlier eating.

Food intake can be increased by learning to anticipate the omission of subsequent meals. We present here a new theory that such anticipatory eating depends on an associative process of instrumental reinforcement by the nutritional repletion that occurs when access to food is restored. Our evidence over the last decade from a smooth-brained omnivore has been that food after deprivation rewards intake even when those reinforced ingestive responses occur long before the physiological signals from renewed assimilation. Effects of food consumed after self-deprivation might therefore reward extra eating in human beings, through brain mechanisms that could operate outside awareness. That would have implications for efforts to reduce body weight. This food reward mechanism could be contributing to the failure of the dietary component of interventions on obesity within controlled trials of the management or prevention of disorders such as hypertension, atherosclerosis and type 2 diabetes.

Reinforcement of anticipatory eating by short as well as long fasts.

Rats can learn to anticipate the omission of subsequent meals by increasing food intake. Our previous reports have analysed group means at each trial but that does not allow for rats learning at different speeds. This paper presents instead a rat-by-rat analysis of all the raw data from previous experiments. The re-analysis supports the published evidence that the capacity for reinforcement generated by withholding of food is greater after a longer fast than after a shorter fast, but that the learning is quicker after the shorter fast. The individualised analyses also extend the evidence that the pattern of learning, extinction and re-learning with shorter fasts is similar to that with longer fasts. These findings indicate that, contrary to our previous interpretation, a single learning mechanism can explain the effects of both durations of food deprivation.

Perception as interacting psychophysical functions. Could the configuring of features replace a specialised receptor?

This paper illustrates how perception is achieved through interactions among the psychophysical functions of judged features of an object. The theory is that the perceiver places processed features in a multidimensional space of discriminal processes. Each dimension is scaled in units of discrimination performance. The zero coordinate of each feature is its level in an internal standard (norm) established by previous experience of that category of object in context. Experiments are reported which show that one, two, or three concurrent single-featured objects matched the multiple features of another object in two ways. Either stimulation from the two objects had discrimination distances from norm that added, or the stimulation by one object was processed through a concept describing stimulation by the other object. It follows that, in this case, perception via a receptor for the multi-featured object can be replaced by a point of balance among receptors for each single feature. The object with its own receptor is the gustatory stimulant L-glutamic acid as its monosodium salt. The features that stimulate diverse gustatory receptors of their own are sodium chloride, citric acid, sucrose, and caffeine. A more complex approach to dimensional coding was developed earlier for photoreceptors in colour judgments. The present approach is modality independent, mathematically simple, and economical in experimental data.

Insight into sight, touch, taste and smell by multiple discriminations from norm.

The paper presents an innovative theory of perception of multiple features across and within modalities. Each step is illustrated by an aspect of data from diverse experiments. The theory is that a template or norm of previously configurated features is used to perceive an object in a situation, such as consuming an item of food or drink. A mouthful usually stimulates sight first and then touch, taste and smell, with thermal, irritative, kinaesthetic and auditory patterns often also involved. The visual information also typically includes meanings of words, numbers and pictures. Attended sensory and symbolic features of the situation are integrated by the individual into a multidimensional distance from the norm. Dimensions are calibrated in units of the response's discrimination between levels of each stimulus feature. This approach to perceptual performance is expounded for sensed and/or conceived visual features of drinks and foods, and their tasted or smelt constituents, or felt and heard cracking during a bite. In addition, the conceptual process that informs an analytical judgment can influence another judgment. Applying the concept to a stimulus forms a descriptive process. A concept may also be applied to another concept or to a description, giving greater depth of meaning to an integrative judgment. Furthermore, a description can be applied to an environmental source of stimulation, creating a percept that presumably is conscious, whereas unconceptualised stimulation may be subconscious.

Situation-specific cognitive behavioural self-therapy for erroneously suspected allergy or intolerance to a food. A short self-assessment tool.

The recall of personal experiences relevant to a claim of food allergy or food intolerance is assessed by a psychologically validated tool for evidence that the suspected food could have caused the adverse symptom suffered. The tool looks at recall from memory of a particular episode or episodes when food was followed by symptoms resulting in self-diagnosis of food allergy or intolerance compared to merely theoretical knowledge that such symptoms could arise after eating the food. If there is detailed recall of events that point to the food as a potential cause of the symptom and the symptom is sufficiently serious, the tool user is recommended to seek testing at an allergy clinic or by the appropriate specialist for a non-allergic sensitivity. If what is recalled does not support the logical possibility of a causal connection between eating that food and occurrence of the symptom, then the user of the tool is pointed to other potential sources of the problem. The user is also recommended to investigate remedies other than avoidance of the food that had been blamed.

Haptic signals of texture while eating a food. Multisensory cognition as interacting discriminations from norm.

This study started to characterise the cognitive processes by which physical effects on the senses are transformed into quantitative judgments about conceptualised aspects of a food. Using words provided by assessors, discriminations of a shortbread biscuit's fracturing patterns during eating from each assessor's internal norm were measured for the initial steps of denting, biting and crushing the material. The haptic concept of dentability (lack of crispness) often discriminated cracks in the biscuit that were the lowest in force, but was also sensitive to high-force cracks and frequency of cracks. How hard it was to bite through the sample was most often sensitive to the force of snapping the biscuit and to high-force cracks. Frequency of cracks usually dominated how "crunchy" the biscuits were rated to be. Interactions among the normed discrimination functions accounted for judgments of overall distance from the personal norm for the complex overall texture of the biscuit and revealed each assessor's cognitive strategies in reaching those integrative judgments. Use of the haptic concepts tended to shift mentation from control of the integrative texture ratings directly by sensory stimulation to the relating of those concepts to the sensed patterns, i.e., to describing texture.

Aversive viscerally referred states and thirst accompanying the sating of hunger motivation by rapid digestion of glucosaccharides.

Associative conditioning of satiety indicates that concentrated maltodextrin (cMD) may induce a mildly aversive visceral signal within 20 min of its ingestion, as well as satiating normally. Individuals' awareness of this adverse state was tested on ratings of statistically distinct descriptions of factors liable to suppress hunger, whether distressing or comfortably satisfying. Wanted amount of a food and the pleasantness of eating it correlated highly for each of five foods, once again refuting the widespread presumption that "pleasant" refers to sensory pleasure; hence, as in previous reports, suppression of hunger was measured as a reduction of the averaged pleasantness of functionally related foods. At 20 min after the start of ingestion of a small meal on a near-empty stomach, cMD reliably reduced hunger. The greatest influence on hunger, besides normal sating, was thirst, but there were also tendencies to nausea and bloat, although all less than after a full sized meal. Visceral processes shortly after a meal can create dissociable conscious states, only one of which is satiety for food.

Targeting cultural changes supportive of the healthiest lifestyle patterns. A biosocial evidence-base for prevention of obesity.

This paper argues that the rise in obesity can be slowed only by universal education based on a type of evidence that does not yet exist. On top of literacy and numeracy, people need the ability to preempt the fattening effect of a decrease in habitual physical activity by altering familiar patterns of eating, drinking and exercise in ways that are both maintainable within the individual's social and physical environment and also effective at decreasing weight to the asymptote for each sustained change. Hence the prevention of obesity requires locally valid evidence on which changes to specific customary habits actually do avoid unhealthy fattening. Interventions need to focus on antecedents to individuals' common lapses from the healthy changes in these customs. Yet no research has been funded into the public's descriptions of feasible changes that cause a step down in weight, let alone into the environmental conditions for individuals' maintenance of those changes. As a result, public health policies on obesity lack scientific basis. When will a start be made on systematic identification of cultural supports to readily executed patterns of lifestyle behaviour which improve health to extents that have been directly measured?

Learned liking versus inborn delight: can sweetness give sensual pleasure or is it just motivating?

In this study, we separated for the first time the learned liking for a particular level of sweetness in a familiar drink from the infantile delight in sweetness as such ("the sweeter, the better"). It is widely assumed that sensing a liked food or drink evokes a pleasurable experience, but the only psychological evidence for this assumption has been tongue movements that are elicited specifically by sweet taste in animals and human neonates. We found that adults felt such movements in response to drinking juice at both their personally preferred level of sweetness and levels they deemed so sweet as to be undrinkable. Yet only the intolerably strong level of sweetness elicited enjoyment of the experienced movements, elevation of mood, and a sense of smiling. Hence, the pleasure that adults experience during ingestion could be exclusively linked with the congenital sweetness reflex that sends mother's milk down an infant's throat.

Satiety. No way to slim.

This short overview considers a prospect that claims to boost satiety are used to prescribe or sell materials to dieters that do not slow their daily rate of energy intake, thereby worsening their problems with body weight and even perhaps increasing the prevalence of obesity. Implying that a drug or a food contributes to weight control by providing extra satiety is a mistake in two ways. First, the notion of a hormone analogue or a food constituent having a specifiable satiating power is scientifically incoherent. Secondly, a slimming satiety is a particular pattern of eating and drinking, in which substances have no fixed roles. Such a dietary custom has to be shown to produce a larger step decrease in weight with the medication or food product than without it. Suppression of food intake at a usual time for eating does not imply reduction in the eater's total intake of energy in a calendar period and hence lower weight while the material is still used within that eating pattern. It is the maintained pattern of behaviour that slims and prevents regain, not a satiety-augmenting substance. Regulators should not allow incomprehension of the basic science of energy balance to be exploited by advocacy of a food or medication for "satiety" believed by consumers to be a means of avoiding unhealthy fatness.

Users of 'diet' drinks who think that sweetness is calories.

We present the first experiment that was based on a novel analysis of the mental processes of choice. Sensed material characteristics such as the sweetness of a drink and symbolic attributes such as the source of sweetness stated on the label are put into the same units of influence on the response. Most users of low-calorie drinks thought about the energy in a drink quite differently from the way they decided how sweet and how low in calories they liked the drink to be. Also the female diet drink users thought about energy content differently from most of the male users of sugar drinks. In both groups' ratings of likelihood of choice and in sugar drink users' estimates of energy content, sweetness and labelled calories were usually treated as separate stimuli or ideas. In contrast, some female diet drink users treated sweetness and perceived calories as the same, whereas no male sugar drink user did. Such findings illustrate how this approach spans the gap between sensory perception and conceptualised knowledge.