Jason Halford

Effect of television advertisements for foods on food consumption in children

The impact of television (TV) advertisements (commercials) on childrens eating behaviour and health is of critical interest. In a preliminary study we examined lean, over weight and obese childrens ability to recognise eight food and eight non-food related adverts in a repeated measures design. Their consumption of sweet and savoury, high and low fat snack foods were measured after both sessions. Whilst there was no significant difference in the number of non-food adverts recognised between the lean and obese children, the obese children did recognise significantly more of the food adverts. The ability to recognise the food adverts significantly correlated with the amount of food eaten after exposure to them. The overall snack food intake of the obese and overweight children was significantly higher than the lean children in the control (non-food advert) condition. The consumption of all the food offered increased post food advert with the exception of the low-fat savoury snack. These data demonstrate obese childrens heightened alertness to food related cues. Moreover, exposure to such cues induce increased food intake in all children. As suggested the relationship between TV viewing and childhood obesity appears not merely a matter of excessive sedentary activity. Exposure to food adverts promotes consumption.

Beyond-brand effect of television food advertisements on food choice in children: the effects of weight status

OBJECTIVE To investigate the effect of television food advertising on childrens food intake, specifically whether childhood obesity is related to a greater susceptibility to food promotion. DESIGN The study was a within-subject, counterbalanced design. The children were tested on two occasions separated by two weeks. One condition involved the children viewing food advertisements followed by a cartoon, in the other condition the children viewed non-food adverts followed by the same cartoon. Following the cartoon, their food intake and choice was assessed in a standard paradigm. SETTING The study was conducted in Liverpool, UK. SUBJECTS Fifty-nine children (32 male, 27 female) aged 9-11 years were recruited from a UK school to participate in the study. Thirty-three children were normal-weight (NW), 15 overweight (OW) and 11 obese (OB). RESULTS Exposure to food adverts produced substantial and significant increases in energy intake in all children (P < 0.001). The increase in intake was largest in the obese children (P = 0.04). All children increased their consumption of high-fat and/or sweet energy-dense snacks in response to the adverts (P < 0.001). In the food advert condition, total intake and the intake of these specific snack items correlated with the childrens modified age- and gender-specific body mass index score. CONCLUSIONS These data suggest that obese and overweight children are indeed more responsive to food promotion, which specifically stimulates the intake of energy-dense snacks.

Serotonergic drugs : effects on appetite expression and use for the treatment of obesity.

Over 35 years of research suggests that endogenous hypothalamic serotonin (5-hydroxytryptamine) plays an important part in within-meal satiation and post-meal satiety processes. Thus, the serotonin system has provided a viable target for weight control, critical to the action of at least two effective anti-obesity treatments, both producing clinically significant weight loss over a year or more. Numerous serotonin receptor subtypes have been identified; of these, serotonin 5-HT1B and 5-HT2C receptors have been specifically recognised as mediators of serotonin-induced satiety.A number of serotonergic drugs, including selective serotonin reuptake inhibitors (SSRIs), dexfenfluramine and 5-HT2C receptor agonists, have been shown to significantly attenuate rodent bodyweight gain. This effect is strongly associated with marked hypophagia and is probably mediated by the hypothalamic melanocortin system. Additionally, sibutramine, dexfenfluramine, fluoxetine and the 5-HT2C receptor agonist chlorophenylpiperazine (mCPP) have all been shown to modify appetite in both lean and obese humans, resulting in reduced caloric intake. Clinical studies demonstrate serotonergic drugs specifically reduce appetite prior to and following the consumption of fixed caloric loads, and cause a reduction in pre-meal appetite and caloric intake at ad libitum meals. Weight loss in the obese has also been produced by treatment with both the serotonin precursor 5-hydroxytryptophan and the preferential 5-HT2C receptor agonist mCPP.A new generation of 5-HT2C receptor selective agonists have been developed and at least one, lorcaserin (APD356), is currently undergoing clinical trials. In addition, 5-HT6 receptor antagonists such as PRX-07034 and BVT74316 have been shown to potently reduce food intake and bodyweight gain in rodent models and have recently entered clinical trials. However, the role of the 5-HT6 receptor in the expression of appetite remains to be determined. The hope is that these drugs will not only be free of their predecessors’ adverse effect profiles, but will also be equally or more effective at regulating appetite and controlling bodyweight.

Television Food Advertising to Children: A Global Perspective

OBJECTIVES We compared television food advertising to children in several countries. METHODS We undertook a collaboration among 13 research groups in Australia, Asia, Western Europe, and North and South America. Each group recorded programming for 2 weekdays and 2 weekend days between 6:00 and 22:00, for the 3 channels most watched by children, between October 2007 and March 2008. We classified food advertisements as core (nutrient dense, low in energy), noncore (high in undesirable nutrients or energy, as defined by dietary standards), or miscellaneous. We also categorized thematic content (promotional characters and premiums). RESULTS Food advertisements composed 11% to 29% of advertisements. Noncore foods were featured in 53% to 87% of food advertisements, and the rate of noncore food advertising was higher during childrens peak viewing times. Most food advertisements containing persuasive marketing were for noncore products. CONCLUSIONS Across all sampled countries, children were exposed to high volumes of television advertising for unhealthy foods, featuring child-oriented persuasive techniques. Because of the proven connections between food advertising, preferences, and consumption, our findings lend support to calls for regulation of food advertising during childrens peak viewing times.

The Power of Food Scale. A new measure of the psychological influence of the food environment.

This paper describes the psychometric evaluation of a new measure called the Power of Food Scale (PFS). The PFS assesses the psychological impact of living in food-abundant environments. It measures appetite for, rather than consumption of, palatable foods, at three levels of food proximity (food available, food present, and food tasted). Participants were 466 healthy college students. A confirmatory factor analysis replicated the three-factor solution found previously by Capelleri et al. [Capelleri, J. C., Bushmakin, A. G., Gerber, R. A., Leidy, N. K., Sexton, C., Karlsson, J., et al. (in press). Discovering the structure of the Power of Food Scale (PFS) in obese patients. International Journal of Obesity, 11, A165]. The PFS was found to have adequate internal consistency and test-retest reliability. The PFS and the Restraint Scale were regressed on four self-report measures of overeating. The PFS was independently related to all four whereas the Restraint Scale was independently related to two. Expert ratings of items suggested that the items are an acceptable reflection of the construct that the PFS is designed to capture. The PFS may be useful as a measure of the hedonic impact of food environments replete with highly palatable foods.

Beyond-brand effect of television (TV) food advertisements/commercials on caloric intake and food choice of 5-7-year-old children.

Food advert exposure has been shown to influence calorie intake and food choice in 9-11 year olds. However, little is known about the effect of food advertisements on feeding behaviour in younger children. Therefore, we conducted a study with 93 children aged 5-7 years, 28 of whom were over weight or obese. The children were exposed to 10 non-food adverts and 10 food adverts in a repeated measures design. Their consumption of sweet and savoury, high and low fat snack foods, and fruit were measured following both sessions. Food advert exposure produced a significant increase in total food intake in young children. The collection of recognition data was incomplete. These data replicate previous findings in that exposure to food adverts increases food intake in all children, but recognition of food adverts is related to body mass index (BMI). Beyond their effects on brand choice, exposure to food advertisements (commercials) promotes over-consumption in younger children.

SB‐334867, a selective orexin‐1 receptor antagonist, enhances behavioural satiety and blocks the hyperphagic effect of orexin‐A in rats

Intracerebroventricular (i.c.v.) administration of the novel hypothalamic neuropeptide orexin‐A stimulates food intake in rats, and delays the onset of behavioural satiety (i.e. the natural transition from feeding to resting). Furthermore, preliminary findings with the selective orexin‐1 receptor antagonist, SB‐334867, suggest that orexin‐A regulation of food intake is mediated via the orexin‐1 receptor. At present, however, little is known about either the intrinsic effects of SB‐334867 on the normal structure of feeding behaviour, or its effects upon orexin‐A‐induced behavioural change. In the present study, we have employed a continuous monitoring technique to characterize the effects of SB‐334867 (3–30 mg/kg, i.p.) on the microstructure of rat behaviour during a 1‐h test with palatable wet mash. Administered alone, SB‐334867 (30 mg/kg, but not lower doses) significantly reduced food intake and most active behaviours (eating, grooming, sniffing, locomotion and rearing), while increasing resting. Although suggestive of a behaviourally nonselective (i.e. sedative) action, the structure of feeding behaviour was well‐preserved at this dose level, with the reduction in behavioural output clearly attributable to an earlier onset of behavioural satiety. As previously reported, orexin‐A (10 µg per rat i.c.v.) stimulated food intake, increased grooming and delayed the onset of behavioural satiety. Pretreatment with SB‐334867 dose‐dependently blocked these effects of orexin‐A, with significant antagonism evident at dose levels (3–10 mg/kg) below those required to produce intrinsic behavioural effects under present test conditions. Together, these findings strongly support the view that orexin‐A is involved in the regulation of feeding patterns and that this influence is mediated through the orexin‐1 receptor.

Behavioral satiety sequence (BSS) for the diagnosis of drug action on food intake.

The Behavioral Satiety Sequence (BSS) is the name given to the orderly transitions of eating, activity grooming and resting measured during the postingestive period. Because the BSS is considered to reflect the operations of natural physiological processes underlying satiety, the sequence can be used to discriminate between different drugs (and other manipulations) that reduce food intake via these natural physiological mechanisms or those that do so by interference. The BSS is only produced by the presence of a caloric load in the gut, and the preabsorptive satiety factors (such as CCK) the caloric load triggers. The BSS is most accurately defined by continuous observation rather than time or event sampling techniques [Partial Time Sampling (PTS) or Momentary Time Sampling (MTS)]. Continuous observation also allows the true duration and true frequency of each behavior to be analyzed. Continuous observation can be used to determine if the profiles associated with the reduction in food intake is caused by nausea, sedation, hyperactivity, or altered palatability of food. At the present time is it possible to identify a number of drugs whose suppression of food intake is associated with the disruption or preservation of the BSS. Drugs that increase synaptic 5-HT activity such d-fenfluramine, fluoxetine. and sibutramine all preserve the BSS and advance the onset of resting. The 5-HT1b/2c agonists mCPP and TFMPP and the 5-HT1b agonist CP-94,253 produce similar effects. However, the 5-HT2 agonist DOI and the 5-HT1a/1b agonist RU-24969 disrupt the BSS by inducing hyperactivity as does amphetamine. The 5-HT2 agonist MK-212 disrupts the BSS by inducing sedation. Selective dopamine agonists, at low doses, such as SKF-38393 (DA1) and LY-171555 (DA2) also preserve the BSS. However, detailed behavioral analysis of the effects of many recently discovered putative satiety factors remains to be carried out.

Separate systems for serotonin and leptin in appetite control

Appetite control involves an integration of the drive signals arising form energy stores in the body with the satiety signals generated by periodic episodes of food consumption. Serotonin (5-hydroxytryptamine, 5-HT) has been implicated in the processes of within-meal satiation and postmeal satiety (5-HT1B and 5-HT2C, postsynaptic receptors) which are concerned with the signals arising form the pattern of food intake. Central nervous system (CNS) 5-HT is sensitive to circulating levels of the precursor tryptophan, certain macronutrients and peripheral satiety factors such as cholecystokinin (CCK) and enterostatin. Hypothalamic 5-HT receptor systems inhibit neuropeptide Y (NPY), a potent stimulator of hunger and food intake. In contrast to the linking of 5-HT with the consequences of food ingestion, the hormone leptin (OB protein) is regarded as a signal linking adipose tissue status with a number of key CNS circuits. Leptin itself stimulates CNS leptin receptors (OB-r receptor) which link with pro-opiomelanocortin (POMC)/MC-4 receptors. The effects of leptin may also be modulated by factors such as the corticotrophin-releasing factor (CRF), cocaine and amphetamine-regulated transcript (CART), orexins and galanin. Very little evidence exists to support any direct link between the actions of 5-HT and leptin, suggesting that they are separate systems. 5-HT is a part of an integrated network for short-acting satiety signals (episodic in nature), and leptin is a hormonal indicator of long-term (tonic) energy reserves. At a conceptual level, these may represent the distinction between ‘satiety’ and ‘drive’. Interestingly, both 5-HT and leptin modulate the action of NPY, which may form a part of a common output pathway for the expression of appetite.

Television advertising and branding: Effects on eating behaviour and food preferences in children

Television provides one of the first, and most intimate, experiences of commercial food promotion. Therefore, unsurprisingly, the effects of television advertising on childrens brand preferences are well established. However, its effect on actual food intake and the food choices in children of various weight statuses has only recently been characterised. Despite regulation, children in the UK are exposed to considerable numbers of food adverts on television. These are predominantly for foods high in fat, salt and sugar (HFSS), which are marketed to children using promotional characters and themes of fun. Such adverts have been shown to cause significant increases in intake, particularly in overweight and obese children, and enhanced preference for high carbohydrate and high fat foods in children who consume the greatest amounts of televisual media.