This is an invited research digest contributed by Dr. Sofia Vilela at the University of Porto, Portugal.
Dietary recommendations from the World Health Organization include the consumption of a wide variety of foods consisting mainly from plants in preference to animals’ sources [1,2]. Eating a variety of healthy foods allows us to achieve an optimal nutritional status and a complete coverage of essential nutrients. But, what do we mean by a higher variety in diet?
A varied diet comprehends a high consumption of different foods or food groups. For example, not only eating the 5-a-day recommendation of fruit and vegetables but including as many different foods as possible in the diet. In that sense, several scientific studies have supported the beneficial effect of diet variety, through an increase of variety of nutrient-dense foods within and across food groups, on health outcomes, for instance, a lower prevalence of type 2 diabetes, metabolic syndrome, hypertension and obesity [3-7].
However, key messages should focus on a greater variety of healthy foods over energy-dense foods, the former being previously associated with a lower prevalence of excessive weight, with the latter being associated with a higher body weight . Beyond the nutritional benefits, diet variety also influences other dimensions of eating, such as the pleasure of eating . A varied diet, including foods differing in taste, flavor, and texture can increase the pleasure of eating, promoting, for example, the acceptance of a new food or a previously disliked food.
Researchers from Porto University (Portugal) have assessed the overall variety of the diet from a sample of 4537 children when they were 4 and 7 years of age . These children belong to the population-based birth cohort Generation XXI, assembled in Porto (Portugal) that have been following 8647 children since birth. Parents were questioned about the food consumption of the child at 4 and 7 years of age, including a list of foods or food groups, and the respective frequency of consumption (ranging from never to more than 4 times per day) in the previous six months.
This study has analyzed that an early exposure to a higher dietary variety of healthy foods, such as fruit and vegetables, influences the children’s appetite and their relationship with food. Indeed, a varied diet improves the children’s eating behaviors related to appetite; children are less fussy, accept new foods more easily, and have a higher enjoyment of food. These children also have a lower desire to drink sugar-sweetened beverages . A lower variety of healthy foods are associated with a higher avoidance of foods, which may increase the risk of malnutrition in these children.
These results support that parents should invest in food variety starting at early ages and adopt specific strategies to promote the acceptance and consumption of healthy foods. For some foods, such as vegetables, parents need to expose the child to the new foods up to 8-10 times for the child to accept the food [12-14]. This exposure could occur, for example, every week with different food preparations. Cooking skills could also be used, modifying the confection of the food to make it more palatable or increasing accessibility to healthy foods at home.
Another strategy is to give a non-food reward to the child, such as a sticker, to encourage the child to try the new food. The child should not be rewarded with foods that he or she enjoys, because that may have the opposite effect intended. The child may grow to further dislike the vegetable (new food) and desire more of the chocolate (food that he/she already likes).
 WHO. Preparation and Use of Food-Based Dietary Guidelines. WHO Technical Report, Series 880. Report of a Joint FAO/WHO Consultation. World Health Organization, Geneva, Switzerland.1996.
 World Health Organisation European Region. Food based dietary guidelines in the WHO European Region. World Health Organization, Copenhagen, Denmark. 2003.World Health Organisation European Region.
 Foote JA, Murphy SP, Wilkens LR, Basiotis PP, Carlson A. Dietary variety increases the probability of nutrient adequacy among adults. Journal of Nutrition. 2004 Jul;134(7):1779-85.
 Murphy SP, Foote JA, Wilkens LR, Basiotis PP, Carlson A, White KK, et al. Simple measures of dietary variety are associated with improved dietary quality. Journal of the American Dietetic Association. 2006 Mar;106(3):425-9.
 Steyn NP, Nel JH, Nantel G, Kennedy G, Labadarios D. Food variety and dietary diversity scores in children: are they good indicators of dietary adequacy? Public health nutrition. 2006 Aug;9(5):644-50.
 Vadiveloo M, Parkeh N, Mattei J. Greater Healthful Food Variety as Measured by the US Healthy Food Diversity Index Is Associated with Lower Odds of Metabolic Syndrome and its Components in US Adults. Journal of Nutrition. 2015 Mar;145(3):564-71.
 Conklin AI, Monsivais P, Khaw KT, Wareham NJ. Dietary Diversity, Diet Cost, and Incidence of Type 2 Diabetes in the United Kingdom: A Prospective Cohort Study. PLoS medicine. 2016 Jul;13(7):e1002085.
 Vadiveloo M, Dixon LB, Parekh N. Associations between dietary variety and measures of body adiposity: a systematic review of epidemiological studies. British Journal of Nutrition. 2013 May;109(9):1557-72.
 Nicklaus S. The role of food experiences during early childhood in food pleasure learning. Appetite. 2016 Sep 1;104:3-9.
 Vilela S, Hetherington MM, Oliveira A, Lopes C. Tracking diet variety in childhood and its association with eating behaviours related to appetite: The generation XXI birth cohort. Appetite. 2018 Apr 1;123:241-8.
 Cooke L. The importance of exposure for healthy eating in childhood: a review. Journal of Human Nutrition and Dietetics. 2007 Aug;20(4):294-301.
 Remington A, Anez E, Croker H, Wardle J, Cooke L. Increasing food acceptance in the home setting: a randomized controlled trial of parent-administered taste exposure with incentives. The American Journal of Clinical Nutrition. 2012 Jan;95(1):72-7.
 Wardle J, Herrera ML, Cooke L, Gibson EL. Modifying children’s food preferences: the effects of exposure and reward on acceptance of an unfamiliar vegetable. European journal of clinical nutrition. 2003 Feb;57(2):341-8.