Behaviour change for better health: nutrition, hygiene and sustainability.

As the global population grows there is a clear challenge to address the needs of consumers, without depleting natural resources and whilst helping to improve nutrition and hygiene to reduce the growth of noncommunicable diseases. For fast-moving consumer goods companies, like Unilever, this challenge provides a clear opportunity to reshape its business to a model that decouples growth from a negative impact on natural resources and health. However, this change in the business model also requires a change in consumer behaviour. In acknowledgement of this challenge Unilever organised a symposium entitled 'Behaviour Change for Better Health: Nutrition, Hygiene and Sustainability'. The intention was to discuss how consumers can be motivated to live a more healthy and sustainable lifestlye in today's environment. This article summarises the main conclusions of the presentations given at the symposium. Three main topics were discussed. In the first session, key experts discussed how demographic changes - particularly in developing and emerging countries - imply the need for consumer behaviour change. The second session focused on the use of behaviour change theory to design, implement and evaluate interventions, and the potential role of (new or reformulated) products as agents of change. In the final session, key issues were discussed regarding the use of collaborations to increase the impact and reach, and to decrease the costs, of interventions. The symposium highlighted a number of key scientific challenges for Unilever and other parties that have set nutrition, hygiene and sustainability as key priorities. The key challenges include: adapting behaviour change approaches to cultures in developing and emerging economies; designing evidence-based behaviour change interventions, in which products can play a key role as agents of change; and scaling up behaviour change activities in cost-effective ways, which requires a new mindset involving public-private partnerships.

Validation of food diaries as measures of dietary behaviour change.

This study aimed to validate the ability of a 24-h food diary (the DIET-24) to accurately detect change in children's fruit and vegetable consumption at school snack time following implementation of the Food Dudes healthy eating intervention. Participants were 4- to 9-year-old children from two primary schools in England. There were 148 participants in the intervention school and 43 participants in the no intervention control school. For each child, snack-time fruit and vegetable consumption was measured separately by weight (grammes), and compared with teachers' estimates (to the nearest half portion) using the DIET-24. Both consumption measures were taken at T1 (pre-intervention) and T2 (post-intervention). At each time-point, Spearman rank correlations between the two measures were low to moderate, but significant. However, when compared with weighed measures, the DIET-24 did not always accurately detect significant changes in children's fruit and vegetable consumption following the intervention. To provide sensitive measures of behaviour change, it is important that dietary measures assess as accurately as possible the amount of food consumed, rather than, as is often the case, rely on all-or-none portion estimates. This issue is important for the establishment of a reliable evidence-base for healthy eating interventions.

Increasing pre-school children's consumption of fruit and vegetables. A modelling and rewards intervention.

Using a repeated measures design, in a nursery setting, a modelling and rewards intervention targeted preschool children's consumption of 8 fruit and 8 vegetables (presented as 4 different food sets, each comprising 2 fruit and 2 vegetables). During the 16-day Baseline 1, and subsequent baselines, the children received a different food set daily, first at snacktime and again at lunchtime; consumption of these foods was not rewarded. In the 32-day fruit intervention phase, Food Set 2 and Food Set 3 were presented on alternate days; rewards were presented only at snacktime, and only for consumption of the fruit components. Following Baseline 2 and Baseline 3, the intervention targeted snack consumption of the vegetable components of Food Sets 1 and 4. Finally, Baseline 4, and 6-month Follow up were conducted. The interventions produced large and significant increases in target fruit and vegetable consumption with smaller, but significant, increases for the paired, opposite category, non-target foods. Immediately after each intervention, increases based on within-category generalisation were also evident. All increases generalised strongly to the no-rewards lunchtime context. Contrary to theories predicting response decrements, the increases in preschoolers' fruit and vegetable consumption were maintained at Follow up, six months after rewards were withdrawn.

Naming and categorization in young children: v. manual sign training.

Following pre-training with everyday objects, 8 children aged from 2 to 4 years learned to produce one manual sign (fists placed one above the other, in front of body) to one stimulus and an alternative manual sign (shoulders touched with ipsilateral hands) to the other stimulus, with each of three pairs of different arbitrary wooden shapes (Set 1). The six stimuli then were presented in category match-to-sample tests, which all subjects passed. Three of the children were next trained to produce the manual signs (denoted as fist/shoulder) for an additional six arbitrary stimuli, Set 2. All 3 children went on to pass category match-to-sample tests for Set 2, and for Set 1 and Set 2 combined. In the final experimental phase, 2 of the children were trained, for one of the six stimulus pairs, to produce the vocal tact "zag" to one stimulus and "vek" to the other. Both children showed category transfer of these vocalizations in test trials with each of the remaining five stimulus pairs, and all the stimuli combined in a 12-stimulus array. In line with Horne and Lowe's (1996) naming account, manual sign naming was found to be as effective as vocal naming in establishing arbitrary stimulus categorization, measured in terms of category sorting and transfer of function. The findings also have implications for the training of verbal repertoires in people with learning disabilities.

Naming and categorization in young children: IV: listener behavior training and transfer of function.

Following pretraining with everyday objects, 14 children aged from 1 to 4 years were trained, for each of three pairs of different arbitrary wooden shapes (Set 1), to select one stimulus in response to the spoken word /zog/, and the other to /vek/. When given a test for the corresponding tacts ("zog" and "vek"), 10 children passed, showing that they had learned common names for the stimuli, and 4 failed. All children were trained to clap to one stimulus of Pair 1 and wave to the other. All those who named showed either transfer of the novel functions to the remaining two pairs of stimuli in Test 1, or novel function comprehension for all three pairs in Test 2, or both. Three of these children next participated in, and passed, category match-to-sample tests. In contrast, all 4 children who had learned only listener behavior failed both the category transfer and category match-to-sample tests. When 3 of them were next trained to name the stimuli, they passed the category transfer and (for the 2 subjects tested) category match-to-sample tests. Three children were next trained on the common listener relations with another set of arbitrary stimuli (Set 2); all succeeded on the tact and category tests with the Set 2 stimuli. Taken together with the findings from the other studies in the series, the present experiment shows that (a) common listener training also establishes the corresponding names in some but not all children, and (b) only children who learn common names categorize; all those who learn only listener behavior fail. This is good evidence in support of the naming account of categorization.

Naming and categorization in young children: III. Vocal tact training and transfer of function.

Following pretraining with everyday objects, 10 children aged from 1 to 4 years were given common vocal tact training with a set of three pairs of arbitrary stimuli of differing shapes; Set 1. Nine children learned to tact one stimulus as "zog" and the other as "vek" in each pair, and all passed subsequent pairwise tests for the corresponding listener behavior to each listener stimulus (i.e., /zog/ and /vek/, respectively). The children were next trained to clap to one stimulus of Pair 1 and wave to the other, and all then showed name-consistent transfer of these behaviors to the stimuli of Pair 2 and Pair 3. Seven children also were given a test of listener responding to experimenter-modeled clap and wave gestures, respectively, which they all passed. Four of the children next participated in a category match-to-sample test for the Set 1 stimuli; all 4 passed. For each pair of two additional six-stimuli sets, Set 2 and Set 3, 3 children were trained to wave to one stimulus and to clap to the other. For each set, all 3 children showed perfect transfer of the vocal tacts trained to Set 1, and of listener behavior both to the auditory stimuli /zog/ and /vek/ and to experimenter-modeled clap and wave gestures. They also sorted the stimuli perfectly in category match-to-sample tests for Set 2, Sets 1 and 2 combined, Set 3, and Sets 1, 2, and 3 combined. The results show that even in very young children, naming is a powerful means of generating new category relations among as many as 18 arbitrary stimuli.

Naming and categorization in young children: II. Listener behavior training.

Following pretraining with everyday objects, 1- to 4-year-old children received listener training with three pairs of arbitrary stimuli of differing shapes. For each pair, 9 children were trained to select one stimulus in response to the spoken word /zog/ and the other to the spoken word /vek/. Next, in the look-at-sample category match-to-sample test, none categorized the six stimuli correctly when asked to look at the sample before selecting from five comparisons. Seven of these children failed a subsequent test of corresponding speaker behavior (tact test); following tact training, 5 of them passed either a repeat of the look-at-sample category test (2 subjects) or an alternative category test (3 subjects) in which they were required to tact the sample before selecting comparisons. The remaining 2 failed both category tests. Of the 2 who passed the tact test, 1 passed the tact-sample category test; the other failed to complete category testing. Two children were next given a second stimulus set. One passed the look-at-sample category test and the tact test; the other failed both tests but passed the tact-sample category test after tact training. The results show that 1- to 4-year-old children may learn listener behavior without corresponding speaker behavior. The results also show that common listener behavior is not sufficient to establish arbitrary stimulus classes, and they are consistent with the proposition that naming may be necessary for categorization of such stimuli.