The health stakes of dietary quality are considerable. Poor diets fuel obesity, type 2 diabetes, heart disease and several cancers, and they increase the risk of premature death. In Australia and the United States, roughly one-third of the calories consumed by adults come from what researchers call discretionary foods and drinks: ultra-processed, energy-dense products loaded with sugar, salt and saturated fat, such as chips, burgers and ice-cream. Against that backdrop, the UTS team, which brought together expertise from medical science, psychology and marketing, wanted to understand whether feelings about brands, rather than knowledge about nutrition, might be quietly steering population-level eating patterns. Their conclusion is that aggressive and pervasive marketing of fast-food brands may be helping to drive the increase in chronic diet-related diseases by shaping not just purchases but perceptions.

Senior author Dr Poppy Watson of UTS explained the core mechanism identified by the study. When people develop a psychological loyalty to fast-food brands, she said, it acts as a strong predictor of their saturated fat and sugar intake, regardless of how healthy they perceive those brands to be. This is a subtle but important distinction. Public health campaigns have long assumed that if consumers understand which foods are unhealthy, they will adjust their behaviour accordingly. The new findings suggest the picture is far more complicated, because brand affection appears to operate on a separate track from nutritional knowledge, and on that track it is affection that tends to win.

Perhaps the most counterintuitive result is that people who love fast-food brands actually rate those brands as healthier. Senior author Dr Mike Kendig, a senior lecturer in Medical Science at UTS, noted that nutritional knowledge does play a role in health ratings, but that the strongest predictor of how healthy a brand is perceived to be is simply how much a person likes it. The researchers suggest that repeated exposure to branding builds familiarity and positive feelings, and that these feelings spill over into health perceptions and dietary choices. Familiar logos, jingles and mascots, encountered across retail environments, media, sport and everyday life, may therefore function as a kind of emotional seasoning that makes energy-dense products seem more benign than they are.

The study was conducted in two parts, involving adult participants in both Australia and the United States. Researchers assessed attitudes toward fast-food and beverage brands, measured perceived healthiness of those brands, and administered a comprehensive dietary questionnaire. By combining brand-level affect with detailed dietary recall, the team could test whether liking predicted actual intake of fat and sugar. It did. Participants who expressed stronger liking for fast-food brands not only consumed more fat and sugar overall but also tended to perceive those brands as healthier than less enthusiastic respondents did. The consistency of the pattern across two countries and two separate studies strengthens the case that brand attachment is a meaningful behavioural signal rather than a statistical fluke.

It is tempting, the researchers acknowledge, to assume that the occasional fast-food treat says little about the rest of a person’s diet. The data tell a different story. Liking fast-food brands was associated with poorer overall diet quality, meaning the attachment flagged broader patterns of eating rather than isolated indulgences. This makes brand affinity a potentially useful marker for health professionals and researchers: a simple question about how someone feels toward major fast-food and soft-drink brands may reveal more about their habitual diet than a question about what they believe is healthy. It also suggests that interventions targeting brand attitudes, not just nutritional knowledge, could be a promising avenue for improving population diets.

Dr Watson emphasised just how deliberate and effective the marketing behind these attachments is. Unhealthy food marketing is pervasive in retail, media, sport and other settings, she observed, and companies would not invest so heavily in it if it were not incredibly effective at shaping purchase decisions. It is self-evident that the marketing works, she argued, but consumers are not always cognisant of how it operates on them. The study’s findings give that observation empirical teeth: the emotional bonds forged by advertising are measurable, and they correlate with the fat and sugar people actually put in their bodies. Marketing, in this view, is not merely promoting a choice among foods; it is recalibrating the perceived healthiness of the foods themselves.

The implications for public health policy are significant. Governments and public health organisations invest heavily in nutrition education on the assumption that knowledge helps people make healthier choices. The UTS research suggests this assumption captures only part of the story, because an emotional attachment to a favourite fast-food brand can shape what ends up on a person’s plate despite nutrition warnings. The findings lend support to calls for greater restrictions on junk-food advertising and other government policies aimed at reducing the grip of fast-food giants, such as limits on marketing to children, restrictions on sponsorships of sport, and clearer labelling regimes. Dr Watson argued that individuals need to be aware of how much marketing biases health perceptions and influences eating, but that there is also a broader responsibility to rein in such marketing, because the evidence shows it is shaping diets at a population level.

For consumers, the study offers a practical, if uncomfortable, takeaway: the warm feelings a brand inspires are not neutral. They are the product of billions of dollars of exposure engineering, and they can quietly distort judgments about healthiness while correlating with diets higher in saturated fat and sugar. Recognising that affection for a logo may be a better predictor of diet quality than a nutrition quiz could help people interrogate their own preferences more honestly. For researchers, the work opens questions about how brand attachments form, how malleable they are, and whether reducing exposure could weaken the link between brand love and poor diet. For policymakers, it strengthens the evidence base for treating food marketing as a public health issue on par with tobacco and alcohol advertising. What people feel about fast-food brands, this research makes clear, is not just a matter of taste; it is a measurable force in the health of nations.

Subject of Research: The relationship between fast-food brand liking, perceived brand healthiness and overall diet quality in adults.

Article Title: How you feel about fast-food brands can predict overall diet quality

Article References: How you feel about fast-food brands can predict overall diet quality. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: fast food, brand loyalty, diet quality, junk food marketing, sugar-sweetened beverages, nutrition, obesity, public health, health communication, consumer behaviour, chronic disease, University of Technology Sydney