Since the 1970s, western diets increasingly consist of processed foods rich in saturated fat, sugar, and sweeteners; a trend ultimately crossing the globe resulting in an obesity epidemic [1, 2]. Compared to 1975, global obesity rates have almost tripled, with 39% of men and 40% of women being overweight or obese in 2016 [3]. Similarly, according to Eurostat, 53% of the EU population was overweight among which 17% was obese in 2019 [4]. With poor diet and obesity being important risk factors for most non-communicable diseases, obesity manifests a high burden on public health [5, 6]. On a personal level, obese people have a 32% higher medical spending compared to normal weight people [6]. On a societal level, the OECD countries estimate to spend 8.4% of their health budget on treating the consequences of high body mass in the period 2020–2050 [7].

The foregoing numbers indicate obesity prevention is highly called for. Unfortunately, governmental efforts to promote healthier food choices so far seem to have little effect. While people consider health experts and governmental agencies to be trustworthy, adherence to nutritional guidelines remains rather low, with people perceiving the information as confusing and hard to understand [8, 9]. Meanwhile, data from the US, Finland, Canada, Norway and Australia show how mass media, and in particular the internet, has become an increasingly prominent source of food information in Western societies over the past two decades [10, 11].

The increasingly prominent role of mass media as a source of food information started with the boom in cooking television at the start of the twenty-first century [12, 13]. TV chefs achieved a celebrity-like status and multiple countries like the US, UK and Belgium got their own TV network solely broadcasting cooking shows [12, 13]. While the recipes used in these cooking shows and promoted by celebrity chefs have been criticized in the past for being too rich in protein, total fat, saturated fatty acids, and salt, it is unclear whether they have any effect on the dietary behavior of their viewers [14–16]. Some studies suggest that cooking shows and celebrity chef content can increase the intake of specific food groups as well as the time spent on cooking among their viewers [12, 17–19]. Other studies reject this notion, claiming people consume celebrity chef content rather as entertainment, finding hardly any relation with dietary behavior [20, 21].

Besides cooking television, online media has become an increasingly prominent source of food information. A review from Boylan et al. [8] even reported online media as people’s main source of dietary information. Clarke et al. [22] reported how celebrity chefs are widely prominent on multiple social media platforms such as Facebook, Instagram, and Pinterest. Similarly, Elias [23] pointed out that online media has democratized food writings as everybody can share their own recipes with a wider audience. This gave opportunity to lifestyle gurus or influencers, defined by Baker and Rojek [24] as “unlicensed native agents of awareness, positioned in conventional and social media, to offer emotional support, an identity matrix and pedagogy for self-discovery and well-being” to gain prominence. Online media made it easier than ever to establish a forum and promote certain diets or lifestyles, even if the claims made are not scientifically substantiated.

While also lifestyle gurus have received criticism from the scientific community [9, 25], their followers perceive them as authentic and trustworthy due to their personal discourse and the role model function they portray [26–28]. As is the case for celebrity chef content, it is unclear how content provided by lifestyle gurus affects dietary behavior. A survey from Byrne et al. [27] found lifestyle gurus to be highly influential for 16% of the respondents, while 32% of the respondents reported to be motivated to eat healthier. This may, however, be deceptive, as lifestyle gurus advocate for healthy diets by “clean eating” in which nutrients and foods like carbohydrates, dairy, fat or sugar ought to be restricted, something that is not in line with dietary guidelines [27]. Looking at recipes provided by lifestyle gurus on online blogs, they were higher in protein and fat compared to other online recipes, while there was no difference in sugar or salt [29]. This does not insinuate a healthier diet, as the recipes of popular food blogs already contain too high amounts of saturated fat and salt [30].

Considering the increasing influence of mass media and the possible implications it has on dietary behavior, the aim of this study is to examine to what extent the Flemish adult population uses mass media content to obtain food information and how using this information associates with dietary behavior, as measured by dietary intake and dietary restrictions.

Table 3 shows the popularity of all food information. Celebrity chefs were the most popular, with 37% of respondents using them as their main source of food information. Family and acquaintances (21%) came in second, followed by lifestyle gurus (12%), online sources (7%), experts (6%), magazines (5%), supermarkets (5%), traditional cookbooks and organizations (5%), and TV channels (5%). Furthermore, 21% of the respondents reported they did not use any source of food information. Notably, following lifestyle gurus was correlated with being female (r = 0.16, p < 0.001), having a higher education (r = 0.12, p < 0.001), and being younger (r = −0.07, p = 0.01). Similarly, there was a correlation between following celebrity chefs and being female (r = 0.07, p = 0.015). A more extensive correlation matrix is presented in Supplementary Appendix S2.

Table 3 shows the association between using different food information sources and dietary restrictions. In total, 8.1% of the respondents were on a diet, while 36% were avoiding certain food components.

Table 3 shows that respondents who used lifestyle gurus as a main source of food information had the most dietary restrictions. They were more likely to avoid carbohydrates (OR = 2.55, 95% CI = 1.21–5.37), sugar (OR = 2.53, 95% CI = 1.59–4.04, fat (OR = 2.53, 95% CI = 1.48–4.33, and dairy (OR = 2.64, 95% CI = 1.01–5.37) (all p < 0.05) (see Table 2). People who use experts as an information source were more likely to follow a diet (OR = 3.28, 95% CI = 1.60–6.75, p = 0.001) and to restrict certain food components (OR = 4.10, 95% CI = 1.60–6.75, p < 0.001) in general. They also showed an odds ratio of 2.53 (95% CI = 1.45–4.41) and 2.23 (95% CI = 1.21–4.12) to avoid sugar, and avoid fat (all p < 0.05). In contrast, the use of supermarkets, online sources, magazines, tv channels, traditional sources, and celebrity chefs was not associated with any dietary restrictions (Supplementary Appendix S3).

Table 4 shows that respondents who turn to lifestyle gurus for information consumed fruits, vegetables, legumes, processed and unprocessed meat replacers, plant-based dairy alternatives, nuts and seeds, light soda, cereal, and fish more frequently (all OR’s ranging from 1.45 to 2.36, all p’s < 0.05). Among these vegetables, nuts and seeds and plant based dairy showed an OR higher than 2. They also consumed soda, processed red meat, white bread, and potatoes (all OR’s ranging from 0.61 to 0.72, all p < 0.05) less often. Respondents who use celebrity chefs as an information source ate vegetables, soda, white bread, water, pastry, cereal, cheese, milk-based drinks, semi-skimmed and skimmed milk, processed and non-processed red meat, non-processed white meat, and potatoes more often (all OR = 1.29–1.53, all p’s < 0.05). Respondents relying on experts for information consumed fruit, processed and unprocessed meat replacers, yoghurt, nuts, and seeds more often (all OR’s ranging from 1.73–2.19, all p’s < 0.05), while consuming semi-skimmed and skimmed milk and potatoes less often (all OR’s ranging from 0.59–0.62, all p’s < 0.05). The usage of other food information sources relates only to the intake frequency of 3 food groups or fewer.

In light of the wide availability of food information and the increased availability of mass media, a survey among a sample of the Flemish adult population was set up to measure the most popular food information sources and their relations with dietary intake and dietary restrictions.

Most people in this study mentioned celebrity chefs, family or acquaintances, and lifestyle gurus as their most popular source of food information. Following celebrity chefs was correlated with being male. This is in line with Taillie [38], who reported an association between the rise of celebrity chefs and the number of men cooking at home. Being female and having a higher education was associated with obtaining advice from lifestyle gurus. A plausible explanation is a greater concern around healthy eating, fear of gaining weight and a poorer self-body image, which are main motivators for adhering to fad diets [39, 40]. Notably, only 6% of the respondents mentioned experts, primarily doctors and dieticians, as their main source of food information. This further supports the idea of people turning to media for food information, while experts, who have smaller media platforms, are losing their role as gatekeeper [8, 41].

As for dietary restrictions, 8.1% of the respondents were on a diet. Experts were the only food information source associated with dieting. Besides the number of respondents following a specific diet, 36% of the respondents reported avoiding certain food components. As suggested by Byrne et al. [27], having dietary restrictions was associated with using lifestyle gurus as a main source of food information, but also with using experts. Using lifestyle gurus as a main source of information was specifically associated with avoiding carbohydrates, sugar, fat, and dairy, while respondents who used experts as a main source were more likely to avoid sugar and fat. The rather low number of dieters and rather high avoidance of food components among people who turn to lifestyle gurus could be attributed to the tendency of lifestyle gurus to not position their guidelines as a “diet.” As the saying goes, “it is not a diet, it is a lifestyle.” The two most popular Flemish lifestyle gurus, Sandra Bekkari and Pascale Naessens, indeed express their detest for the word diet by publishing books called “ik haat diëten” (I hate dieting) and “nooit meer diëten” (never diet again).

The extent to which the use of specific food sources was associated with the intake frequency of different food groups varies. Lifestyle gurus show the greatest relation, as using them as a main source of food information was associated with the intake frequency of 14 food categories and the highest OR among these categories. The most popular source, celebrity chefs, was associated with 13 food categories. Experts came in third, showing an association with seven different food categories. Other information source categories only showed an association with three or fewer categories.

The high number of associations and higher OR with lifestyle gurus has multiple explanations. A first could be the “guru effect.” According to this theory, people tend to “judge profound what they failed to grasp” [42]. Considering the confusion many people have regarding healthy food, they can perceive rather obscure opinions of lifestyle gurus as a sign of intelligence [41]. In contrast to experts, whose ideas and guidelines change over time because of new findings, gurus are more likely to stick to their own idea and provide certainty [41]. Additionally, Baker and Rojek [26] also noted that the relationship between lifestyle gurus and their audience is an important factor [26]. Lifestyle gurus are relatable, they talk about the same struggles and experiences as normal people but also seem to excel in their roles, making them exemplary. Furthermore, Schouten et al. [28] reported a difference in “identification with” and “credibility” as the reason why the endorsement of influencers (lifestyle gurus) is more influential than that of celebrities. Similarly, Zopiatos and Melanthiou [13] also attributed the influence of celebrity chefs to the observation that consumers relate to them and consider them to be trustworthy.

When looking at the specific food groups lifestyle gurus was not only associated with a more frequent consumption of vegetables, fruit, light soda, cereal, nuts, seeds, processed and unprocessed meat replacers, plant-based dairy alternatives, fish, and legumes, but also with less frequent consumption of soda, potatoes, processed red meat, and white bread. Considering that the general population in Flanders eats too few legumes, fruit, vegetables, nuts, seeds, and whole grains, while consuming too much meat, it implicates lifestyle gurus may promote more healthy dietary choices [43, 44]. Similarly, using experts as an information source was associated with more frequent consumption of fruit, processed and unprocessed meat-replacers, yoghurt, nuts, and seeds as well as the less frequent consumption of potatoes, as well as semi-skimmed and skimmed milk. While dairy is still included in Belgian dietary guidelines, some studies suggest that replacing dairy with nuts and other plant based sources would have a beneficial effect on cardiovascular and all-cause mortality [45, 46]. Similarly, as the Flemish population consumes too much meat, meat replacers have been suggested as a healthy and more environmentally friendly alternative [47]. However, processed meat substitutes often score very high on sodium and sugar rendering also these products less healthy [48, 49]. It is also notable that potatoes were eaten less often by both those who report following experts and those following lifestyle gurus. According to the Belgian nutritional guidelines, potatoes can be part of a healthy diet. However, other sources (e.g., the nutritional guidelines from Harvard) suggest potatoes possess too few vitamins and a too-high glycemic index [50].

Respondents who turned to chefs as information sources ate vegetables, soda, water, white bread, pastry, cereal, cheese, milk based drinks, semi-skimmed and skimmed milk, processed and non-processed red meat, non-processed white meat, and potatoes more often. The OR were however, smaller compared to the OR of lifestyle gurus and experts. The frequent use of potatoes in the traditional Belgian kitchen could explain the high potato consumption in these groups. Additionally, high pastry consumption could reflect the increasing popularity of baking shows like “Bake Off.” Increases in the consumption frequency of vegetables, white bread, meat, and cheeses were likely a result of their frequent use in the recipes of chefs. As using celebrity chefs as a food information source had a positive association with the intake frequency of food groups like water and vegetables which are consumed too infrequently, but also with white bread, pastry, processed red meat which are consumed too frequently, it is not possible to conclude whether it associates with a more or less balanced dietary intake [34].

Considering the criticism from the scientific community on diets endorsed by lifestyle gurus, it is rather surprising that the results show a positive relation between following lifestyle gurus and dietary components that are consumed insufficiently among the general population. However, it is notable that most popular lifestyle gurus referenced in this questionnaire strive toward consuming less processed foods, which is indeed beneficial considering the association processed food consumption has with obesity, overall cancer, all-cause mortality, cardiovascular diseases and depression [51, 52]. The restriction against carbohydrates, fat, and dairy is more controversial, as dietary restrictions or “clean eating” is often associated with eating disorders [53, 54]. Similarly the focus on restricting macronutrients has shown only limited effect on weight control, while putting people at risk for nutritional deficiencies, alterations in the gut microbiota and metabolic side-effects [54–57]. With food media becoming increasingly popular, this study underlines the need for more research on the influence food media has on diet.