Early life review

The health status of an individual depends on the conditions in which he/she is born and the intra-uterine life is important for that outcome (Gluckman & Hanson 2008). Moreover the study of the first years of a child’s life provides an important indicator for their health, nutritional status and wellbeing of the population. Maternal

31 nutritional status at the time of the pregnancy as well as her health history have proven to be determinants for their children’s health in many studies (Moreira et al. 2007; Varela-Silva et al. 2009; Marques 1999; Baker et al. 2004; Poston 2012; Harding, Boroujerdi, et al. 2006; Reilly et al. 2005).

If poor nutrition (Thame et al. 1997) was associated with smaller and shorter babies, overweight/obese mothers were more likely to have children suffering from over nutrition at 5 years (Janjua et al. 2012). Moreover an incorrect diet (FFQ) based on low intake of fibre and high intake of fat and carbohydrates and low birth weight were shown to increase the chance of developing childhood obesity and later metabolic syndrome and diabetes in a review paper (Misra et al. 2009).

Actually a wide variety of different risk factors at different stages might influence children’s nutritional status. For example, maternal weight gain is a good indicator of the nutrient availability for the fetus and can be influenced by several variables like age, ethnicity, parity, lifestyle, socioeconomic status, drug, alcohol and tobacco use (Marques 1999). A higher weight gain during pregnancy was associated with a higher offspring‘s adult BMI but was not associated with adiposity outcome (skinfolds) in adulthood. In 2006 Moreira and Padrão (Moreira & Padrão 2006) showed that among Portuguese mothers a maternal weight gain during pregnancy higher or equal to 16Kg represented an increased OW/OB risk in the offspring. Furthermore Moreira (Moreira 2007) also presented an important relationship between maternal excessive weight gain and her obese offspring. In a cross-sectional study, Portuguese researchers demonstrated that the probability of a child having increased risk of OW/OB was greater in mothers with considerable weight gain in pregnancy (Padez et al. 2009). Also the World Health Organization (WHO), defends exclusive breastfeeding should be continued for the first 6 months of age (Saadeh 2003) to have a protective effect against obesity in all world populations (Kries et al. 1999; Bosnjak & Grgurić 2013). However, breastfeeding length and its effect on OW/OB outcomes do not show consensus among researchers. Some indicate that breastfeeding (Arenz et al. 2004) has an inverse relation with childhood obesity. If some studies validate this relation (Moschonis et al. 2008) others could not find significant relationships (Davis et al.

32 2007). Another study identifies the importance of breastfeeding in reducing the probability of becoming OW/OB (Horta et al. 2007). In addition other researchers also found that breastfeeding protected against overweight, high blood cholesterol, high blood pressure and type II diabetes (Plagemann & Harder 2005). The fact that breastfeeding shows a different type of association might be related to study designs and type of measures collected (Davis et al. 2007; Arenz et al. 2004). It might also be due to the different characteristics of the populations studied and age range selected (Davis et al. 2007). The protective effect of breastfeeding may also depend on the ethnic group studied (Grummer-Strawn & Mei 2004; Hediger et al. 2001).

Overweight or obesity could be associated with pre-gestational and gestational diabetes (Huang et al. 2007). The prevalence for this condition is widely known (Hunt & Schuller 2007; Vibeke Anna et al. 2008; Lawrence et al. 2008; Dabelea et al. 2005) and has been observed in Portugal (Sociedade Portuguesa de Diabetologia 2013). While some authors suggest it’s prevalence to be independent of maternal BMI, age and parity in immigrant populations (Savitz et al. 2008; Caughey et al. 2010) it’s metabolic control throughout pregnancy seems to be influenced by ethnicity/birth place (culture, diet) (Caughey et al. 2010; Torres et al. 2011). In a Norwegian population, Vangen and collaborators (Vangen et al. 2003) concluded that maternal diabetes could be associated with perinatal death. Also a diabetic mother could influence diabetes and obesity in her children (Dabelea et al. 2000). Consequently evidence suggests that even modest increases in maternal BMI could be linked to foetal death, stillbirth, neonatal, perinatal, and infant death (Aune et al. 2014).

Moreover, another study showed that probable early markers of obesity included maternal body mass index, childhood growth patterns (early rapid growth and early adiposity rebound), childhood obesity and father’s employment (a proxy measure for socioeconomic status in many studies) (Brisbois et al. 2012).

Furthermore risk factors for obesity also included obese parents, restricted growth, low/high birth weight (BW) and low socioeconomic status even though their effect is difficult to assess (Monasta et al. 2010). A review paper considered obesity to be favoured by rapid growth, maternal diabetes, short sleep hours, lower physical activity

33 levels (less than daily 30 min) and sugar sweetened beverages consumption (Monasta et al. 2010). The strongest predictors were breastfeeding length, infant dimensions, short sleep hours and TV viewing. For breastfeeding length it was associated with lower overweight prevalence. The higher odds ratio were found for babies only breastfed for 1 month and lower when breastfed between 7-9 months (Harder et al. 2005).

On the other hand maternal obesity may be related with low socioeconomic status and educational level potentially prompting an obese offspring (Monasta et al. 2010). Moreover paternal BMI has also been positively associated with waist circumference in their descendants (Labayen et al. 2010).

There is research on the effect of birth weight (BW) (Brisbois et al. 2012) and infant size on a child's risk of OW/OB. Some researchers found a significant relationship between birth weight and obesity in the early life course stages (infancy and childhood) (Martins & Carvalho 2006) and for different countries (Reilly et al. 2005; Mamun et al. 2005; Jones-Smith et al. 2007). Nevertheless, there might be some inconsistencies. When growth is restrained during gestation it is reflected in a child’s birth weight and may condition higher fat deposition and insulin resistance (Ibáñez et al. 2006). A review paper showed the relationship between infant size/ growth and subsequent OW/OB (Baird et al. 2005). Values falling on each end of birth weight, both low and high, could be predisposing factors for later development of obesity. Some researchers found increased risk of obesity (Guo et al. 2000) or abdominal obesity (check waist to hip ratio) (Laitinen et al. 2004) with low birth weight and a higher birth weight was positively associated with increased adult BMI or OW/OB rates. There seems to be a positive association between birth weight with waist circumference in men (Kuh et al. 2002), a negative association with waist-hip-ratio but not with waist circumference in women.

The review of the biological literature combined concepts and theories derived from other approaches and disciplines. The analytical model presented shows how the accumulation of disadvantages during the life course point to subsequent intergenerational effects.

34 Figure 2. 10. Analytical model on theories explored to determine intergenerational influences on child nutrition.