Nutritional interventions addressing food choices and eating behaviour

Eating behaviour is generally defined as any response to food-related stimuli resulting in food intake, which is driven by a complex interaction of several factors, such as physiological, sensory, perceptual, cognitive, psychological, and environmental ones. Current research accounts for the wide cross-modulation existing to control appetite between homeostatic and non-homeostatic (reward, emotion, memory, attention, and cognitive) systems via the gut-brain axis. This cross-talk between metabolic and cerebral regulatory systems is coordinated by the brain, which integrates food-related sensory information with satiety signals produced by the gastrointestinal tract to set up a mental representation of food. Those signals allow the evaluation of the reward value of food and the generation of affective responses, determining the regulation of eating behaviour. In order to increase our comprehension of this topic, there is a need for investigations approaching the interaction among homeostatic regulators, reward cues, and motivational signals, within the environment in which this interaction takes place. On the basis of these considerations and to better understand the complex homeostatic-hedonic system underlying food intake control, the main aims of this Doctoral Thesis were i) to explore the association between the compositional and perceived characteristics of food with nutritional, physiological, behavioural, and psychological variables linked to both the homeostatic and reward-related control of food choices and food intake, and ii) to assess the influence of declaring nutritional and compositional characteristics of foods on food choices, through the enhancement of healthy product availability and nutrition communication at the point-of-choice. According to these specific objectives, this Doctoral research was divided in two phases. During the first phase, the effect of breakfast on several factors linked to food intake was assessed through a series of nutritional, behavioural, and neurological studies. Breakfast positively affected appetite control in healthy adults, while consumption of a non-caloric breakfast did not entail nutritional advantages, since it led to a compensatory mechanism in total daily energy intake and hindered the achievement of nutrient intake recommendations. The impact of breakfasts differing in their nutritional and perceptual characteristics needs to be further explored in a shorter time period like, for instance, the morning snacking occasion. This could avoid fasting-like scenarios, while still retaining an effect on factors involved in food intake regulation. In such a way, the sensory, saliency, and reward-related attributes of food that can stimulate food intake might be reduced in favour of physiological and cognitive factors. To deeper investigate the impact of perceptual and cognitive characteristics on food choices, a behavioural intervention addressing food choices and promoting healthy dietary habits, whilst not limiting the freedom of choice of consumers, was carried out during the second phase of this Doctoral research. Enhancing the availability of healthy foods at the point-of-choice increased their purchase, nudging the exposure to healthy foods towards healthy food choices. The communication of product attributes only discouraged selection of less favourable foods, without significantly modifying consumer choices. In conclusion, the findings of this Doctoral Thesis contribute to shed light on the complex interaction of the several drivers of food choices and eating behaviour. Actually, this Doctoral research yielded useful insights for the implementation of nutrition interventions aiming to promote the consumption of healthy foods and entail eating behaviour improvement by nudging food choices through cognitive aspects and educational approaches.