The main findings of this study were that half of all infants were fed with tiny tastings already in the fourth month and that the earlier the infant started with tiny tastings, the earlier they ate larger amounts of solid food. In the multivariate linear regression analysis, five factors were identified as having a negative effect on the duration of breastfeeding: the infant’s age upon introduction of tiny tastings, low maternal age, low level of maternal education, high maternal BMI and twin birth.

The Swedish recommendation to offer tiny tastings from four months of age contradicts the WHO’s recommendation [1], and its impact on breastfeeding has not been studied before. This study shows negative effects on breastfeeding duration. To recommend exclusive breastfeeding for six months could help to scale up breastfeeding and generate benefits besides those of the breastmilk itself, since breastmilk intake among children is associated with lower odds of consuming non-recommended foods, such as cookies, crackers and sweetened drinks [12, 13]. Instead, Nutrition Committees, such as the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition, continue to emphasise the introduction of solid foods from four months of age [14]. In line with the recommendation, the Swedish CHS informs mothers that it is important to start with solid foods when the child is four months old, even when women express that they want to breastfeed exclusively for six months [9]. Addition of solid foods before six months is common in many countries, with one common argument being that this protects against developing food allergies. However, research has not found evidence of any benefits from addition of solid foods before six months, nor any risks related to morbidity or weight change [15]. Another common concern about exclusive breastfeeding for six months is the risk for iron-deficiency anaemia. However, the risk can be successfully mitigated by delayed umbilical-cord clamping [16].

Conflicting advice and non-evidence-based recommendations have a negative effect on breastfeeding [6]. In many ways, it can be perplexing for women to breastfeed in a society that is not infused by a favourable attitude towards breastfeeding. Consequently, breastmilk substitutes have become a “multi-billion dollar industry” that has the opportunity to devote considerable financial resources, influencing women not to breastfeed [17]. Thus, our findings are consistent with previous literature.

The multivariate linear regression analysis showed that low maternal age and low education had a negative impact on breastfeeding. In previous studies, several socioeconomic factors have shown an association with a shorter duration of breastfeeding. For example, mothers with less privileged economic situation and less education have a shorter duration of breastfeeding [18, 19], and mothers with lower age breastfeed for fewer months [19, 20]. This contributes to unequal starting points for children, already from birth. Thus, breastfeeding should be the focus of targeted interventions from the CHS in order to promote equal health. The United Nations’ Sustainable Development Goals compel governments to promote healthy lives and welfare for all. As discussed in previous research, this makes breastfeeding a central part of the 2030 Agenda, since it contributes to the achievement of an equal, healthy, fair, affluent and sustainable future for both people and the planet [21].

This study showed that high BMI in the mother was a significant factor for the shorter duration of breastfeeding. Maternal obesity is linked to many risks, with one of them being a lower initiation rate of breastfeeding and also a greater risk of early breastfeeding cessation [22, 23]. It has been suggested that the causes can be a mix of physiological, behavioural, sociocultural, psychological and medical reasons. For example, obese women can have higher progesterone levels, which may impair lacto genesis. Furthermore, large breasts may lead to problems for the infant to latch on, and the obese mother may lack confidence in the breastfeeding situation because of low body image [24].

Another factor identified as having a negative effect on the duration of breastfeeding in the multivariate linear regression analysis was twin births. Women who have given birth to twins face special challenges, and breastfeeding rates are lower among these infants [25]. According to the mothers, the reasons for weaning twins are insufficient milk supply and infants’ problematic breastfeeding behaviour [26]. This indicates that mothers of twins need targeted breastfeeding support that takes into account these mothers’ unique situation.

This study investigated the impact of tiny tastings on breastfeeding. Data were obtained from many mothers (n = 1,260), and the sample represents different geographical areas, including both high and low socioeconomic statuses. The question measuring breastfeeding duration (exclusive and partial) is very detailed; consequently, it may be more reliable than the Swedish national data [6], even though the retrospective data is a limitation, due to potential recall bias. Conversely, the study design cannot provide causes; rather, it shows associations. The response rate for the follow-up (Q3, n = 1,251), compared with baseline data (a total of 3,389 women completed and returned Q1), was lower. In addition, there might be selection bias, since the study design excluded non-Swedish speaking parents. Moreover, the study’s findings cannot be generalised to infants in other countries than Sweden.