The present study aimed to identify patterns of dietary changes during the COVID-19 pandemic and their associations with sociodemographics, body mass index (BMI) before pandemic, and lifestyle changes in Polish adults and to examine the effects of lockdowns on dietary–lifestyle changes. This study used a cross-sectional online survey to collect data. The k-means algorithm was used to determine of patterns of dietary changes, and logistic regression analyses were performed. During the study period, 43% of respondents decreased physical activity (PA), 49%—increased screen time, and 34%—increased food consumption. Among the three dietary changes patterns, two opposite patterns were found: Prohealthy (28% participants) and Unhealthy (19% participants).The adherence to the Prohealthy pattern was negatively associated with age, but positively with being overweight (aOR 1.31) or obese before pandemic (aOR 1.64). Residing in a macroeconomic region with GDP > 100% decreased adherence to the Prohealthy (aOR 0.73) but increased adherence to the Unhealthy pattern (aOR 1.47). Adults over 40 years old, those living with children, unemployed, those living in a region with a higher GDP, and those not consuming homemade meals could be more exposed to unhealthy behaviors. From a public health perspective, enhancing the message “to be active” during the compulsory isolation period should be prioritized.

The use of dietary supplements (DSs) has been steadily increasing all over the world and additionally, the sales of DSs have dynamical increased in the wake of coronavirus disease 2019 (COVID-19) in most of the countries. We investigated DSs phenomenon in 2020 through (1) exploration of Google searches worldwide and in Poland (with Google Trends (GT) tool), and (2) analyses of results of PLifeCOVID-19 Online Studies conducted during the first and second wave of the pandemic. The conducted GT analysis and cross-sectional studies revealed that during the COVID-19 outbreak in March 2020, the interest in immune-related compounds and foods like vitamins C and D, zinc, omega-3, garlic, ginger, or turmeric, as well as their consumption increased. Improving immunity was the main reason behind the supplementation and changes in consumption of pro-healthy foods. GT analysis has shown these interests were positively correlated with the interest in COVID-19, but adversely with cumulative cases or deaths. Respondents tended to start supplementation during the first COVID-19 wave rather than the second one. Except for the role of vitamins D and C, zinc, and selenium in patients with deficiencies of those nutrients, there are no clear and convincing studies that support the role of DSs use in COVID-19 prevention and treatment in healthy, well-nourished individuals. Moreover, as the risk of elevated intake of some nutrients due to the popularity of DSs exists, effective education of consumers in rationale use of DSs and health-protecting behaviors against COVID-19 should be developed.

To increase teenagers’ nutrition knowledge is an important target and has the potential to improve their dietary habits and lifestyle while reducing incidences of obesity-related non-communicable diseases throughout the whole lifespan. This study protocol presents the general approach and details of an assessment of nutritional knowledge, attitudes toward nutrition, diet quality, lifestyle and body composition that have been used to comprehensively evaluate the cross-behavioral patterns covering dietary and lifestyle behaviors in Polish teenagers. The study was designed in two paths as: a cross-sectional study (covering 1569 students) and an education-based intervention study (464 students) with a 9-month follow-up. We describe a short form of the food frequency questionnaire (SF-FFQ4PolishChildren) used to collect data and details of diet-related and lifestyle-related education program, which was developed and implemented by academic researchers involved in the study. We also describe details of the data development and statistical analysis, including multidimensional methods of clustering variables to identify cross-behavioral patterns covering diet and lifestyle. The results of the study will provide evidence-based support for preventive health care to promote normal growth and development of young population and reduce the risk of diet-related diseases in adulthood, by early shaping of adequate dietary and lifestyle behaviors. In the future, well-tailored education programs addressed to teenagers can be created as an important public health action, based on our results.

Adequate nutrition is particularly important during pregnancy since it is needed not only for maintaining the health of the mother, but also determines the course of pregnancy and its outcome, fetus development as well as the child’s health after birth and during the later period of life. Data coming from epidemiological and interventions studies support the observation that carotenoids intake provide positive health effects in adults and the elderly population. These health effects are the result of their antioxidant and anti-inflammatory properties. Recent studies have also demonstrated the significant role of carotenoids during pregnancy and infancy. Some studies indicate a correlation between carotenoid status and lower risk of pregnancy pathologies induced by intensified oxidative stress, but results of these investigations are equivocal. Carotenoids have been well studied in relation to their beneficial role in the prevention of preeclampsia. It is currently hypothesized that carotenoids can play an important role in the prevention of preterm birth and intrauterine growth restriction. Carotenoid status in the newborn depends on the nutritional status of the mother, but little is known about the transfer of carotenoids from the mother to the fetus. Carotenoids are among the few nutrients found in breast milk, in which the levels are determined by the mother’s diet. Nutritional status of the newborn directly depends on its diet. Both mix feeding and artificial feeding may cause depletion of carotenoids since infant formulas contain only trace amounts of these compounds. Carotenoids, particularly lutein and zeaxanthin play a significant role in the development of vision and nervous system (among others, they are important for the development of retina as well as energy metabolism and brain electrical activity). Furthermore, more scientific evidence is emerging on the role of carotenoids in the prevention of disorders affecting preterm infants, who are susceptible to oxidative stress, particularly retinopathy of prematurity.

There is limited information on the relationships between restrictions linked to COVID-19 and changes in body weight. The aim of the study was to identify the body weight changes and their determinants in the nutritional and socio-demographic context during the COVID-19 pandemic in Polish women. During lockdown in Poland, 34% of women gained weight, while 18% of women reduced weight. As many as 44% of women with obesity before the pandemic increased their body weight, and 74% of women that were underweight reduced their body weight. In a group with weight gain, women increased their body weight by 2.8 kg on average and around 65% of them increased their total food intake. Unhealthy dietary changes and the negative lifestyle changes that comprised of an increase in screen time and a decrease in physical activity were found as key factors associated with weight gain. A higher risk of weight gain was associated with being obese before the pandemic or living in a macroeconomic region >50% of EU-28 GDP, while those younger in age and carrying out remote work had a higher chance of weight loss. Concluding, the specific conditions during lockdown worsened the nutritional status, which may increase the risk of complicatedness and mortality from COVID-19. It seems advisable to create dietary and lifestyle recommendations tailored to the individual needs of women who are underweight or have excessive body weight. More attention should be paid also to environmental impacts. Both, the reduction of excessive body weight and the maintenance of a normal weight should be based on the principle to eat and live sustainably and healthily.

A holistic approach to understanding the relationship between diet, lifestyle and obesity is a better approach than studying single factors. This study presents the clustering of dietary and lifestyle behaviours to determine the association of these dietary-lifestyle patterns (DLPs) with adiposity, nutrition knowledge, gender and sociodemographic factors in teenagers. The research was designed as a cross-sectional study with convenience sampling. The sample consisted of 1549 Polish students aged 11–13 years. DLPs were identified with cluster analysis. Logistic regression modelling with adjustment for confounders was applied. Three dietary-lifestyle patterns were identified: Prudent-Active (29.3% of the sample), Fast-food-Sedentary (13.8%) and notPrudent-notFast-food-lowActive (56.9%). Adherence to Prudent-Active pattern (reference: notPrudent-notFast-food-lowActive) was 29% or 49% lower in 12-year-old or 13-year-old teenagers than in 11-year-old teenagers, respectively, and higher by 57% or 2.4 times in the middle or the upper tertile than the bottom tertile of the nutrition knowledge score. To the contrary, adherence to Fast-food-Sedentary (reference: notPrudent-notFast-food-lowActive) was lower by 41% or 58% in the middle or the upper tertile than the bottom tertile of the nutrition knowledge score, respectively. In Prudent-Active, the chance of central obesity (waist-to-height ratio ≥0.5) was lower by 47% and overweight/obesity was lower by 38% or 33% (depending on which standard was used: International Obesity Task Force, 2012: BMI (body mass index)-for-age ≥ 25 kg/m2 or Polish standards, 2010: BMI-for-age ≥ 85th percentile) when compared with the notPrudent-notFast-food-lowActive pattern. In Fast-food-Sedentary, the chance of central obesity was 2.22 times higher than the Prudent-Active pattern. The study identified a set of characteristics that decreased the risk of general and central adiposity in teenagers, which includes health-promoting behaviours related to food, meal consumption and lifestyle. Avoiding high-energy dense foods is insufficient to prevent obesity, if physical activity and the consumption frequency of health-promoting foods are low and breakfast and a school meal are frequently skipped. The results highlight the importance of the nutrition knowledge of teenagers in shaping their health-promoting dietary habits and active lifestyle to decrease adiposity risk and negative aspects of lower family affluence which promotes unhealthy behaviours, both related to diet and lifestyle.

The first months of infant life are crucial for proper neurodevelopment, which may be influenced by several factors, including nutrition and nutrients (e.g., long-chain polyunsaturated fatty acids (LC PUFA) and carotenoids) of which the concentration in breastmilk is diet-dependent. This study analysed the relationship between the average concentrations of selected LC PUFA and carotenoids in breastmilk samples from the first and third months of lactation and the psychomotor development of exclusively breastfed infants at the sixth month of life. Infant psychomotor development was assessed using the Children Development Scale (DSR). The average age of infants during the assessment was 6.6 ± 0.2 months and 30.9 ± 3.8 years for mothers (n = 39 mother–infant pairs). The average concentration of docosahexaenoic acid (DHA) was 0.50% of fatty acids. The average concentration of carotenoids was 33.3 nmol/L for β-carotene, 121 nmol/L for lycopene and 33.3 nmol/L for lutein + zeaxanthin. The total results of the Performance scale and Motor subscale were 39 centiles and 4.1 points, respectively. Adjusted multivariate regression models revealed associations between breastmilk DHA and motor development (β = 0.275; p ≤ 0.05), α-linolenic acid (ALA; β = 0.432; p ≤ 0.05), n-3 LC PUFA (β = 0.423; p ≤ 0.05) and β-carotene (β = 0.359; p ≤ 0.05). In addition, an association between the Perception subscale and DHA was observed (β = 0.316; p ≤ 0.05; model 2). There were no significant associations between the overall Performance scale scores. Due to the positive association between concentrations of n-3 LC PUFA (ALA and DHA) and β-carotene in breastmilk and infant motor development, it is important to provide these nutrients with breastmilk. According to the diet-dependent concentration of these compounds in breastmilk, breastfeeding mothers should have a diet abundant in dietary sources of these nutrients, e.g., fish, nuts, seeds, vegetable oils, vegetables and fruits.

The sustainability of education focused on improving the dietary and lifestyle behaviours of teenagers has not been extensively studied. The aim of this study was to determine the sustainability of diet-related and lifestyle-related school-based education on sedentary and active lifestyle, diet quality and body composition of Polish pre-teenagers in a medium-term follow-up study. An education-based intervention study was carried out on 464 students aged 11–12 years (educated/control group: 319/145). Anthropometric measurements were taken and body mass index (BMI) and waist-to-height ratios (WHtR) were calculated, both at the baseline and after nine months. Dietary data from a short-form food frequency questionnaire (SF-FFQ4PolishChildren) were collected. Two measures of lifestyle (screen time, physical activity) and two diet quality scores (pro-healthy, pHDI, and non-healthy, nHDI) were established. After nine months, in the educated group (vs. control) a significantly higher increase was found in nutrition knowledge score (mean difference of the change: 1.8 points) with a significantly higher decrease in physical activity (mean difference of the change: −0.20 points), nHDI (−2.3% points), the z-WHtR (−0.18 SD), and the z-waist circumference (−0.13 SD). Logistic regression modelling with an adjustment for confounders revealed that after nine months in the educated group (referent: control), the chance of adherence to a nutrition knowledge score of at least the median was over 2 times higher, and that of the nHDI category of at least the median was significantly lower (by 35%). In conclusion, diet-related and lifestyle-related school-based education from an almost one-year perspective can reduce central adiposity in pre-teenagers, despite a decrease in physical activity and the tendency to increase screen time. Central adiposity reduction can be attributed to the improvement of nutrition knowledge in pre-teenagers subjected to the provided education and to stopping the increase in unhealthy dietary habits.