Why people who think they eat healthily often do not

Many adults are convinced that they eat healthily, but a new study from Italy suggests that this confidence often rests on shaky ground. Researchers surveyed 1,000 Italian adults and found that the feeling of being a healthy eater is driven mainly by psychological factors, particularly a strong healthy self-identity, frequent self-monitoring of one’s health, and confidence in one’s own nutritional knowledge. Yet when these self-perceptions were compared with the respondents’ actual reported food consumption, the alignment was only weak, revealing a substantial gap between how people see their diets and what they actually eat.

The authors set out to address a persistent problem in behavioural nutrition: previous work has documented that people frequently overestimate the quality of their diet, but rarely explains the psychological processes that produce this misperception or identifies who is most likely to misjudge their own eating habits.

To measure actual dietary behaviour, the researchers asked respondents how often they consumed 11 key foods typical of the Mediterranean and Italian diet, using frequency scales and portion-size references validated in prior literature, including the Mediterranean Diet Adherence Screener. Each reported frequency was then compared against thresholds drawn from the guidelines of CREA, the Italian public agency for healthy eating, and scored as either aligned or not aligned with the recommendation. A probabilistic latent class analysis applied to these scores identified three clusters of respondents, and the probability of belonging to the cluster whose consumption patterns matched the guidelines served as the study’s indicator of Healthy Dietary Pattern Adherence.

The psychological side of the model was assessed with Likert-scale questionnaires covering constructs such as Healthy Self-Identity, Health Self-Monitoring, Sustainability Motivation, Subjective Knowledge, Cooking Skills, Motivation to follow a healthy diet, and Healthy Eating Self-Efficacy. The relationships among these constructs and the perceived healthfulness of habitual eating were tested using Partial Least Squares Structural Equation Modelling with 10,000-sample bootstrapping. The researchers also collected an objective measure of nutritional knowledge, scored from incorrect and correct answers, alongside sociodemographic information on gender and age.

The results were striking. Perceived Habitual Dietary Healthfulness was significantly shaped by Healthy Self-Identity, Health Self-Monitoring and Subjective Knowledge, with self-identity emerging as the strongest predictor. Sustainability Motivation and Cooking Skills showed no direct significant effect on perception, but exerted indirect effects mediated through motivation and self-efficacy respectively. By contrast, actual adherence to a healthy dietary pattern was more strongly explained by sociodemographic factors: the likelihood of maintaining a healthy diet increased among women and older individuals, and objective nutritional knowledge predicted actual adherence more strongly than self-perception did.

A correlation analysis of extracted factor scores sharpened the picture. Subjective knowledge was strongly and significantly correlated with perceived dietary healthfulness, while perceived healthfulness was inversely correlated with what respondents actually knew about nutrition. Actual adherence was positively correlated with both types of knowledge, with objective knowledge showing the stronger association. Notably, subjective and objective knowledge were not correlated with each other at all, a dissociation the authors interpret as evidence that confidence in one’s dietary competence may be unreliable as a guide to factual understanding.

To probe the nature of the perception-behaviour gap, the researchers focused on the 250 respondents in the top quartile of perceived dietary healthfulness and split them according to their most likely latent class membership. This yielded 153 respondents whose reported consumption confirmed their positive self-perception, and 97 whose high perceived healthfulness was contradicted by their eating patterns. Compared with the coherent group, the incoherent group showed substantially lower Healthy Self-Identity, lower Cooking Skills, lower Objective Knowledge, and was younger and predominantly male. No significant differences emerged for Self-Monitoring, Motivation, Self-Efficacy, Sustainability Motivation or Subjective Knowledge.

The authors argue that this profile indicates the perception-behaviour gap is not merely a cognitive bias but reflects a specific configuration of weaker identity integration and limited practical competence. For the incoherent segment, a positive view of one’s eating habits appears not to be sufficiently anchored in internalised health values, factual knowledge or everyday food preparation skills to translate into behaviour consistent with dietary guidelines. The finding that motivation and perceived competence did not distinguish the two groups suggests that these factors can reinforce a sense of dietary adequacy that is disconnected from actual intake. The model’s explanatory power was strong for the psychological constructs up to perceived healthfulness, but low for actual adherence, underscoring how little self-perception reveals about real eating patterns.

Some nuances emerged from robustness checks. The analysis identified quadratic relationships between Healthy Self-Identity and Motivation, and between Cooking Skills and Healthy Eating Self-Efficacy. For very high levels of self-identity, its positive influence on motivation weakened and eventually reversed, a saturation effect. In the nonlinear model, cooking skills gained greater significance in determining self-efficacy, particularly at higher levels. The authors also caution that all dietary data were self-reported and may be affected by misreporting and social desirability bias, and that the HDPA index was designed to capture the routinisation of healthy behaviours rather than clinical nutritional accuracy.

The findings carry practical weight for public health communication. Because self-assessed dietary quality can be misleading, the authors suggest that interventions should include mechanisms to disrupt overconfident self-assessments, such as digital tracking of consumption and feedback-based personalised reports. They also point to targeted strategies for the segment most at risk of incoherent self-perception, namely younger and male individuals with lower Healthy Self-Identity and Cooking Skills, recommending skills-based cooking education and communication aimed at strengthening the internalisation of health values. As the study is based on a nationally representative Italian sample, the authors note that the results may not generalise to other cultural or dietary contexts, and future research could test the model cross-culturally and integrate self-reports with objective dietary data.

Subject of Research: Psychological drivers of perceived healthy eating and their alignment with actual diet quality among Italian adults

Article Title: Seeing oneself as a healthy eater: psychological factors underlying the perception of healthy eating and its alignment with actual diet quality

Article References: Fantechi, T., Radicioni, E., Piracci, G., Gerini, F., Contini, C., & Casini, L. (2026). Seeing oneself as a healthy eater: psychological factors underlying the perception of healthy eating and its alignment with actual diet quality. Agricultural and Food Economics, 14(1), Article 71. https://doi.org/10.1186/s40100-026-00509-3

Image Credits: AI Generated

DOI: 10.1186/s40100-026-00509-3

Keywords: dietary self-perception, healthy eating, nutrition, behavioural science, Italy, self-identity, subjective knowledge, cooking skills, diet quality, public health, survey research, PLS-SEM