Direct effects of food cues seen during TV viewing on energy intake in young women

The time-stamped effects of screen exposure on food intake in adults: A meta-analysis of experimental studies

OBJECTIVE

The purpose of this study was to examine time-stamped impacts of screen exposure on food intake among healthy adults.

METHODS

Four electronic databases were searched up to August 31, 2024, including ProQuest, PubMed, Web of Science and Embase. A meta-analysis of inverse variance was used to calculate the standardized mean difference (SMD) in food intake between watching and not watching screen groups, and groups with different screen contents (e.g., food cues).

RESULTS

23 experimental studies with 1894 participants were included. Watching screen (vs. not watching group, SMD: 0.16; 95% CI: 0.06, 0.26; I2 = 42%; p 0.01) significantly increased food intake, while the impact of the contents, including food cues, weight control cues and TV conditions, displayed on screens on food intake was not significantly different. Subgroup analysis revealed that food intake increased significantly with exposure to screens in females (SMD: 0.20; 95% CI: 0.04, 0.35; I2 = 25%; p = 0.01).

CONCLUSION

Adults especially females eat more while watching screen, whatever the screen content displayed on the screen. Given the influence of study designs, more within-subject studies with high quality were required to understand the intricate relationship between screen exposure and food intake, ultimately managing promoting healthier dietary habits.

Examining the evidence between screen time and night eating behaviour with dietary intake related to metabolic syndrome: A narrative review

Screen time (ST) on digital devices has increased in recent decades due to digital development. Furthermore, constant engagement with digital devices alters sleep patterns, leading to nocturnal eating behaviour among users. These phenomena are therefore of great concern, as digital device addiction and night eating are associated with unhealthy food intake, increasing the metabolic syndrome (MetS) risks. The purpose of this review was to examine the evidence of the influence of ST and night eating behaviour (NEB) on dietary intake and its association with MetS based on previous literature. Prolonged ST and NEB have an association with excessive intake of energy from overconsumption of high-sugar and high-fat foods. However, the relationship between digital content and its influence on food intake is inconsistent. A higher MetS risk was found in individuals with longer ST due to a sedentary lifestyle, while positive energy balance and a shift in circadian rhythm contributed to night eaters. ST and NEB presented with a significant influence on food intake in adults. Additionally, unhealthy food intake due to excessive consumption of empty-calorie foods such as sweet and fatty foods due to addiction to electronic devices and eating at night has a detrimental effect on metabolic function. Therefore, improving food intake by reducing ST and night binges is essential to reduce the risk of MetS.

The Impact of Modifiable Preoral Factors on Swallowing and Nutritional Outcomes in Healthy Adults: A Scoping Review

PURPOSE

Swallowing has previously been characterized as consisting of four phases; however, it has become apparent that these four phases are not truly discrete and may be influenced by factors occurring prior to bolus entrance into the oral cavity (i.e., preoral factors). Still, the relationship between these factors and swallowing remains poorly understood. The aim of this review was to synthesize and characterize the literature pertaining to the influence of preoral factors on swallowing and nutritional outcomes in healthy individuals.

METHOD

We performed a scoping review, searching the databases of PubMed, CINAHL, Cochrane, and Scopus. Search terms included those related to swallowing, experience of preoral factors, and exclusionary terminology to reduce animal and pediatric literature. Our initial search revealed 5,560 unique articles, of which 153 met our inclusionary criteria and were accepted into the review.

RESULTS

Of the accepted articles, 78% were focused exclusively on nutritional outcomes, 17% were focused on both swallowing and nutritional outcomes, and 5% were focused on solely swallowing outcomes. Of the preoral factors examined, 99% were exteroceptive in nature (17% olfactory, 44% visual, 21% auditory, 7% tactile, 11% other), while 1% were proprioceptive in nature.

CONCLUSIONS

This review supports the influence of preoral factors on swallowing and nutritional outcomes. However, there is a large emphasis on the visual modality and on nutritional outcomes. Nearly none of the literature found in this review directly measured swallowing safety, efficiency, or physiology. Future work will benefit from a larger focus on proprioceptive preoral factors as they relate to swallowing outcomes.

Screen use during food consumption: Does it cause increased food intake? A systematic review

Nowadays people use screens, such as mobile phones, television, or tablets, more often during mealtimes, which may have an effect on intake. This review aims to analyze the effect of screen use, during food consumption, on intake. A systematic review was carried out, based on those protocols established by PRISMA. The Cochrane Library, PubMed, Web of Science and Scopus databases were consulted. Experimental studies, published between 2010 and 2021, that recorded individual intake while using screens such as television, cell phones, or tablets, were selected. A total of 7181 relevant articles were obtained, which were then assessed in accordance with predetermined inclusion and exclusion criteria. Finally, 35 studies were included in the complete review: 22 compared different kinds of television content (e.g., adverts), five which compared television versus the absence of screens, four which compared television versus video games, two which compared the use of simultaneous screens, and two studies which included cell phones. A total of 27 studies reported consumption increases related to the presence of advertisements and food signals on screens. No significant differences in intake were reported in the eight studies that reported design or sample size limitations, or lack of control of certain variables. It is thus concluded that screen use during food consumption may increase intake. Education is necessary to regulate the habit of consuming food in the presence of screens. Also, the creation of policies that regulate advertising and food cues on screens are justified and must be accompanied by strategies to monitor compliance. As a limitation, further evidence is necessary in order to determine the effect of mobile phone and tablet use while eating. This protocol was registered via PROSPERO, ID: CRD42020211797.

See the cake and have it too? Investigating the effect of watching a TV cooking show on unhealthy food choices

This study tested whether exposure to food-related (vs. non-food related) TV content would increase unhealthy food choices in unsuccessful restrained eaters (i.e., chronic dieters with low perceived self-regulatory success; PSRS), decrease unhealthy food choices in successful restrained eaters (i.e., chronic dieters with high PSRS), and would not affect food choices in unrestrained eaters (i.e., non-dieters). As such, we attempted to (1) explain previous mixed findings on behavioral effects of exposure to food-related TV content, and (2) generalize previous findings on successful and unsuccessful restrained and unrestrained eaters' differential reactivity to isolated food cues (e.g., food words) to food cues embedded in TV content. In a one-factorial between-subjects experiment, participants viewed a cooking segment in which high-calorie cakes were prepared (n = 50) or a non-food segment (n = 62) of a TV show. The percentage of unhealthy (vs. healthy) food choices in a computerized choice task served as dependent variable. Eating restraint and PSRS were measured afterwards. In contrast to the hypothesis, no three-way interaction between TV content, eating restraint, and PSRS on the percentage of unhealthy food choices was found. However, it was found that overall, people with lower levels of PSRS made a higher percentage of unhealthy food choices compared to people with higher levels of PSRS. Contrasting findings from previous research using isolated food cues, this study showed no evidence of unsuccessful restrained eaters' heightened susceptibility to food cues in TV content, possibly explained by a lower salience of or attention to food cues.

Visual food cues decrease blood glucose and glucoregulatory hormones following an oral glucose tolerance test in normal-weight and obese men

Previous experiments of our group have demonstrated that preprandial processing of food cues attenuates postprandial blood glucose excursions. Here we systematically re-evaluated the glucose-lowering effect of visual food cues by submitting 40 healthy fasted men (20 normal-weight men, mean age 24.8 ± 3.7 years, BMI 21.9 ± 0.3 kg/m²; 20 obese men, 26.8 ± 4.2 years, 34.3 ± 1.3 kg/m²) to an oral glucose tolerance test (OGTT) following exposure to pictures of high-calorie food items versus neutral items. OGTT-related changes in blood concentrations of glucose and relevant glucoregulatory hormones including GLP-1 were assessed and analyzed according to the oral minimal model. Independent of body weight, food-cue compared to neutral stimulus presentation reduced postprandial concentrations of glucose (p = 0.041), insulin (p = 0.026) and C-peptide (p = 0.007); accordingly, oral minimal model analyses yielded a food-cue induced decrease of dynamic-phase insulin secretion (p = 0.036). We also observed a trend towards lower GLP-1 levels directly after food cue stimulation in both body weight groups (p = 0.057), as well as a trend towards decreased heart rate (p = 0.093) and significantly decreased diastolic blood pressure (p = 0.019). While we did not detect indicators of an early rise in insulin levels in terms of a 'cephalic phase insulin response', our findings support the assumption that preprandial processing of food cues exerts marked effect on postprandial glucose regulation, with possible contributions of changes in GLP-1. The mechanisms linking food cue exposure and glucoregulatory improvements should be investigated in greater detail, to potentially open new treatment options for metabolic dysfunctions.

The impact of elevated body mass on brain responses during appetitive prediction error in postpartum women

Repeated exposure to highly palatable foods and elevated weight promote: 1) insensitivity to punishment in striatal regions and, 2) increased willingness to work for food. We hypothesized that BMI would be positively associated with negative prediction error BOLD response in the occipital cortex. Additionally, we postulated that food reinforcement value would be negatively associated with negative prediction error BOLD response in the orbital frontal cortex and amygdala. Postpartum women (n = 47; BMI = 25.5 ± 5.1) were 'trained' to associate specific cues paired to either a highly palatable milkshake or a sub-palatable milkshake. We then violated these cue-taste pairings in 40% of the trials by showing a palatable cue followed by the sub-palatable taste (negative prediction error). Contrary to our hypotheses, during negative prediction error (mismatched cue-taste) versus matched palatable cue-taste, women showed increased BOLD response in the central operculum (pFWE = 0.002; k = 1680; MNI: -57, -7,14) and postcentral gyrus (pFWE = 0.006, k = 1219; MNI: 62, -8,18). When comparing the matched sub-palatable cue-taste to the negative prediction error trials, BOLD response increased in the postcentral gyrus (r = -0.60, pFWE = 0.008), putamen (r = -0.55, pFWE = 0.02), and insula (r = -0.50, pFWE = 0.01). Similarly, viewing the palatable cue vs sub-palatable cue was related to BOLD response in the putamen (pFWE = 0.025, k = 53; MNI: -20, 6, -8) and the insula (pFWE = 0.04, k = 19, MNI:38, -12, -6). Neither BMI at 6-month postpartum nor food reinforcement value was related to BOLD response. The insula and putamen appear to encode for visual food cue processing, and the gustatory and somatosensory cortices appear to encode negative prediction errors. Differential response in the somatosensory cortex to the matched cue-taste pairs to negative prediction error may indicate that a palatable cue may dull aversive qualities in the stimulus.

Joint association of screen time and physical activity with anthropometric measures in Iranian children and adolescents: the weight disorders survey of the CASPIAN-IV study

BACKGROUND

This study aims to assess the joint association of screen time (ST) and physical activity (PA) with anthropometric indices among Iranian children and adolescents.

METHODS

In this national study, 23,183 school students, aged 6-18 years, were studied. By using a multi-stage cluster sampling method, they were selected from rural and urban areas of 30 provinces of Iran. ST and PA were assessed by self-administered validated questionnaires. Height, weight, hip and waist circumferences (WC) were measured according to standard protocols, and body mass index (BMI) was calculated. ST of <2 h per day was categorized as "low" and ≥2 h per day as "high". PA levels were obtained by a 7-day recall of sports or activities that made participants sweat or make their legs feel tired, or games that made them breathe heavily. Using this questionnaire, the score of 1-1.9 was categorized as "low" and scores between 2 and 5 as "high" PA. Logistic regression analyses were used to evaluate the joint association of PA and ST categories with odds of anthropometric measures.

RESULTS

In both genders, those students categorized as "Low PA & High ST" had the highest levels of BMI z-scores (boys: 0.15±1.12, girls: 0.17±1.08), WC (boys: 69.93±13.89 cm, girls: 67.30±11.26 cm), and hip circumference (boys: 82.41±13.90 cm, girls: 84.05±13.7 cm), as well as the highest prevalence of overweight (boys: 15.32%, girls: 14.04%) (p<0.001 in all comparisons). In linear multivariate model, students with "High PA & High ST" had significant increased levels of z-scores for BMI, WC and hip circumference (p<0.05).

CONCLUSIONS

The current findings underscore the importance of reducing ST along with increasing PA for prevention and control of excess weight in children and adolescents.