Childhood is considered an important period for the development of healthy eating behaviours. This study aimed to evaluate the influence of early life factors and sociodemographic characteristics, including early diet quality, on diet quality at 7 years. The sample includes 5013 children evaluated at the ages of 4 and 7 years from the Portuguese birth cohort Generation XXI with complete information on FFQ. A healthy eating index was developed at both ages to assess adherence to the WHO’s dietary recommendations, including eight food groups. Consumption quartiles were obtained for each group at 4 years and assigned a score between 1 and 4. A higher score represents a higher adherence to a better diet (range: 8 to 32). The associations between early life factors and sociodemographic characteristics and the score of the healthy eating index at 7 years were evaluated through linear regression models. The healthy eating index had an average score of 21⋅4 ± 3⋅53 (range: 12 to 32) at 4 years and 20⋅3 ± 3⋅36 (range: 11 to 31) at 7 years. After adjustment for confounders, a positive association was found between the healthy eating index at 4 and 7 years (β = 0⋅384, 95 % CI 0⋅356, 0⋅441). Maternal years of education (β = 0⋅094, 95 % CI 0⋅071, 0⋅116) and dietary score (β = 0⋅182, 95 % CI 0⋅155, 0⋅209) were positively associated with increasing dietary quality from 4 to 7 years. A healthier diet at preschool age, higher maternal education and a healthier diet increase the likelihood of maintaining a high healthy eating index score at school age.

The prevalence of obesity has increased simultaneously with the increase in the consumption of large food portion sizes (FPS). Studies investigating this association among adolescents are limited; fewer have addressed energy-dense foods as a potential risk factor. In the present study, the association between the portion size of the most energy-dense foods and BMI was investigated. A representative sample of 636 British adolescents (11–18 years) was used from the 2008–2011 UK National Diet and Nutrition Survey. FPS were estimated for the most energy-dense foods (those containing above 10·5 kJ/g (2·5 kcal/g)). Regression models with BMI as the outcome variable were adjusted for age, sex and misreporting energy intake (EI). A positive association was observed between total EI and BMI. For each 418 kJ (100 kcal) increase in EI, BMI increased by 0·19 kg/m2 (95 % CI 0·10, 0·28; P< 0·001) for the whole sample. This association remained significant after stratifying the sample by misreporting. The portion sizes of a limited number of high-energy-dense foods (high-fibre breakfast cereals, cream and high-energy soft drinks (carbonated)) were found to be positively associated with a higher BMI among all adolescents after adjusting for misreporting. When eliminating the effect of under-reporting, larger portion sizes of a number of high-energy-dense foods (biscuits, cheese, cream and cakes) were found to be positively associated with BMI among normal reporters. The portion sizes of only high-fibre breakfast cereals and high-energy soft drinks (carbonated) were found to be positively associated with BMI among under-reporters. These findings emphasise the importance of considering under-reporting when analysing adolescents' dietary intake data. Also, there is a need to address adolescents' awareness of portion sizes of energy-dense foods to improve their food choice and future health outcomes.

The present study aimed to evaluate the association between the consumption of energy-dense foods at 2 years of age and the consumption of foods and diet quality at 4 years of age. The sample included 705 children evaluated at 2 and 4 years of age, as part of the population-based birth cohort Generation XXI (Porto, Portugal). Data on sociodemographic and lifestyle factors of both children and mothers were collected by face-to-face interviews. The weight and height of children were measured by trained professionals. Based on FFQ, four energy-dense food groups were defined: soft drinks; sweets; cakes; salty snacks. A healthy eating index was developed using the WHO dietary recommendations for children (2006) aged 4 years. The associations were evaluated through Poisson regression models. After adjustment for maternal age and education, child's carer, child's siblings and child's BMI, higher consumption of energy-dense foods at 2 years of age was found to be associated with higher consumption of the same foods 2 years later. An inverse association was found between the intake ( ≥ median) of soft drinks (incidence rate ratio (IRR) = 0·74, 95 % CI 0·58, 0·95), salty snacks (IRR = 0·80, 95 % CI 0·65, 1·00) and sweets (IRR = 0·73, 95 % CI 0·58, 0·91) at 2 years of age and the consumption of fruit and vegetables at 4 years of age ( ≥ 5 times/d). Weekly and daily consumption of energy-dense foods at 2 years of age was associated with a lower healthy eating score at 4 years of age (IRR = 0·75, 95 % CI 0·58, 0·96; IRR = 0·56, 95 % CI 0·41, 0·77, respectively). The consumption of energy-dense foods at young ages is negatively associated with the diet quality of children a few years later.