Increasing vegetable intakes: rationale and systematic review of published interventions.

PURPOSE: While the health benefits of a high fruit and vegetable consumption are well known and considerable work has attempted to improve intakes, increasing evidence also recognises a distinction between fruit and vegetables, both in their impacts on health and in consumption patterns. Increasing work suggests health benefits from a high consumption specifically of vegetables, yet intakes remain low, and barriers to increasing intakes are prevalent making intervention difficult. A systematic review was undertaken to identify from the published literature all studies reporting an intervention to increase intakes of vegetables as a distinct food group. METHODS: Databases-PubMed, PsychInfo and Medline-were searched over all years of records until April 2015 using pre-specified terms. RESULTS: Our searches identified 77 studies, detailing 140 interventions, of which 133 (81 %) interventions were conducted in children. Interventions aimed to use or change hedonic factors, such as taste, liking and familiarity (n = 72), use or change environmental factors (n = 39), use or change cognitive factors (n = 19), or a combination of strategies (n = 10). Increased vegetable acceptance, selection and/or consumption were reported to some degree in 116 (83 %) interventions, but the majority of effects seem small and inconsistent. CONCLUSIONS: Greater percent success is currently found from environmental, educational and multi-component interventions, but publication bias is likely, and long-term effects and cost-effectiveness are rarely considered. A focus on long-term benefits and sustained behaviour change is required. Certain population groups are also noticeably absent from the current list of tried interventions.

Sensory determinants of stated liking for vegetable names and actual liking for canned vegetables: A cross-country study among European adolescents.

Sensory properties are reported as one of the main factors hindering an appropriate vegetable intake by the young. In the present work the sensory determinants of likings for vegetables were explored in adolescents of four European countries (Denmark, n = 88; France, n = 206; Italy, n = 110 and United Kingdom, n = 93). A questionnaire was designed to study cross country differences in stated liking for and familiarity with a list of vegetables popular among European markets (between-vegetable approach). A within-vegetable comparison approach with actual tasting was used to analyze differences and similarities in liking for canned pea and sweet corn samples across the countries. A close positive relationship between stated liking and familiarity was found. Irrespective of the country, one group of highly liked vegetables (carrots, tomatoes, green salad) was identified, characterized by innately liked tastes (sweet, umami), delicate flavour and bright appealing colour. A second group of highly disliked vegetables consists of cauliflowers and broccoli, characterized by disliked sensations such as bitter taste and objectionable flavour. Internal Preference Maps from actual liking scores indicate that the generally disliked tastes (bitter, sour), are clearly correlated with a negative hedonic response for both peas and sweet corn. The hedonic valence of a generally well accepted taste such as salty and texture descriptors depends on the type of vegetable. Internal preference maps from actual liking data indicate that flavour and appearance descriptors of the distinct sensory properties of each type of vegetable positively affect liking, while the intensity of unusual flavours is related to sample disliking.

Effect of type of TAG fatty acids on lutein and zeaxanthin bioavailability.

The xanthophylls lutein and zeaxanthin probably play a role in visual function and may participate in the prevention of age-related eye diseases. Although a minimum amount of TAG is required for an optimal bioavailability of these carotenoids, the effect of the type of TAG fatty acids (FA) is less clear. The aim was to assess the effect of the type of TAG FA on bioavailability of these xanthophylls. A total of three complementary models were used: an in vitro digestion model to study bioaccessibility, Caco-2 cells to study uptake efficiency and orally administered rats to study in vivo bioavailability. Results showed that lutein and zeaxanthin bioaccessibility was greater (about 20-30 %, P< 0·05) with butter and palm oil than with olive and fish oils. Mixed micelle size, which was significantly lower (about 8 %, P< 0·05) with SFA than with unsaturated FA, was inversely related to lutein and zeaxanthin bioaccessibility. There was no significant effect of the type of TAG FA on xanthophyll uptake by Caco-2 cells, but some compounds present in natural oils significantly affected xanthophyll uptake. Oral administration of rats with spinach and butter over 3 d led to a higher fasting plasma lutein concentration than oral administration with olive or fish oils. In conclusion, dietary fats rich in SFA lead to a higher bioavailability of lutein and zeaxanthin, as compared with fats rich in MUFA and PUFA. This is due partly to the higher bioaccessibility of these xanthophylls in the smaller mixed micelles produced when SFA are incorporated into mixed micelles.

Effect of labeling on new vegetable dish acceptance in preadolescent children.

The aim of this study was to explore the effectiveness of a food-labeling strategy to introduce new versions of foods to children's diets, in natural lunch settings (school canteens). The proposed food involved two different types of vegetables: carrots (very familiar) and broccoli (less familiar), both being prepared and presented for choice in a 'familiar' (known) versus a 'new' (unknown) version. We assessed whether adding a label (either basic or model-related) to new versions of vegetable dishes would increase the likelihood that 8- to 11-year-old children would select the new dishes rather than the familiar versions. In the first condition (no label/control condition), both the familiar and the new versions of the vegetable dishes were presented with absence of any information. In the second condition (basic label condition), the new dish was presented accompanied by a basic label: "new carrot/broccoli recipe". In the third condition (model-related label condition), the new version of the dish was presented with a model-related label: "new carrot/broccoli recipe, Special Mix for Super Heroes". Results showed that children chose significantly more often the familiar version of the dish when no information was given (control condition). The addition of a descriptive label (whether basic or model-related) led to an increased frequency of choice for the new vegetable dish for carrots only, and not for broccoli. This study suggests that adding a label with the vegetable's name can be used to increase children's willingness to select a new version of a vegetable dish instead of a familiar one, at least when the vegetable is familiar to the children (i.e. carrots).

Perceptual and lexical knowledge of vegetables in preadolescent children.

The present study investigated the visual and lexical knowledge of vegetables in children. The purpose of this was to identify both liked and disliked familiar vegetables which will be used in a further study. We explored children's lexical knowledge with a free listing test and their visual knowledge with a picture's sorting test. 145 children between the ages of 8 and 11 years from various living environments of the Rhône-Alpes Region, France, completed both tests. Overall, 54 vegetables were cited, 16 of which were cited by more than 9% of the sample. Carrots, tomatoes and lettuce were the most named vegetables and the best visually recognized by children. Lexical knowledge increased gradually with age. Children from rural areas named significantly more vegetables than those from urban areas. However, visual recognition of vegetables did not change as a function of age or living environment. This suggests that visual categorization allows easier accessing to semantic knowledge than verbal questioning. Finally, the data showed a relation between visual familiarity and liking: the majority of raw vegetables recognized visually were also classified as "liked vegetables". In addition, children declared that they did not want to try most of the unknown vegetables.

Comparison of three nudge interventions (priming, default option, and perceived variety) to promote vegetable consumption in a self-service buffet setting.

BACKGROUND: Dietary choices in out-of-home eating are key for individual as well as for public health. These dietary choices are caused by a wide array of determinants, one of which is automatic decision-making. Nudging is attracting considerable interest due to its understanding and application of heuristic biases among consumers. The aim of this study is to test and compare three nudges in promoting vegetable consumption among test persons in a food lab-based experiment. METHODS: The initial sample consisted of 88 participants recruited in Copenhagen, Denmark. Each study participant was randomly assigned to one of the three experiments: priming, default and perceived variety. The priming arm of the experiment consisted of creating a leafy environment with green plants and an odour of herbs. In the default arm of the experiment, the salad was pre-portioned into a bowl containing 200g of vegetables. The third experiment divided the pre-mixed salad into each of its components, to increase the visual variety of vegetables, yet not providing an actual increase in items. Each individual was partaking twice thus serving as her/his own control, randomly assigned to start with control or experimental setting. RESULTS: The default experiment successfully increased the energy intake from vegetables among the study participants (124 kcal vs. 90 kcal in control, p<0.01). Both the priming condition and perceived variety reduced the total energy intake among the study participants (169 kcal, p<0.01 and 124 kcal, p<0.01, respectively), mainly through a decrease in the meat-based meal component. CONCLUSIONS: Considerable progress has been made with regard to understanding the use of nudging in promoting a healthier meal composition, including increasing vegetable intake. This study suggests that the nature of a nudge-based intervention can have different effects, whether it is increasing intake of healthy components, or limiting intake of unhealthy meal components. This work has demonstrated that consumer behaviour can be influenced without restricting or providing incentives for behaviour change. The present findings have promising application to the foodservice sector.

Consumption of a High Quantity and a Wide Variety of Vegetables Are Predicted by Different Food Choice Motives in Older Adults from France, Italy and the UK.

BACKGROUND: Consumption of a high quantity and wide variety of vegetables is currently recommended for health. Dietary variety can be low, however, particularly for older adults. This study investigated the affective factors associated with the quantity and variety of vegetables consumed by older adults in France, Italy and the UK. METHODS: Adults aged 65 years plus completed questionnaires on self-reported vegetable intake (quantity and variety), liking for vegetables, attitudes towards intake, and demographic variables. RESULTS: In 497 older adults (France, n = 187, Italy, n = 152, UK, n = 158), higher quantities of vegetables consumed were associated with a higher age, affluence score and liking for vegetables, and a lower importance in consumption of familiarity (smallest ß = 0.11, p = 0.03). Greater variety was associated with a higher liking and importance of health benefits, and a lower importance of familiarity (smallest ß = -0.11, p < 0.01). Higher quantity and variety combined (quantity × variety) was associated with a higher age, liking and importance of health benefits, and a lower importance of familiarity (smallest ß = 0.14, p = 0.02). Country-specific effects were also found (smallest ß = 0.20, p < 0.01). CONCLUSIONS: These findings demonstrate a role for liking and a lower concern for eating familiar foods in vegetable consumption, and a particular role for concern for health benefits in the consumption of a greater variety of vegetables.