Preventing Obesity Across Generations

Obese Moms are Likelier to Give Birth to Infants Who Grow Up to Become Obese

Oh Little One, Why Don’t You Go to Sleep & Decrease Your Risk of Obesity?

Obesity rates have become unjustifiable with more than 40% of adult population staying overweight and more than 14% of children existing in the obesity zone. Inappropriate environmental, biological and psychological factors have resulted in a situation where obesity rates have tripled since 1975. We have moved past the fact that adult obesity rates are inappropriately high and now researchers are mainly focusing on childhood obesity rates. 10% of the global population is obese and almost 15% of kids between 2 and 5 years old are obese. We have multiple research on the effect of early life factors and its effect on childhood obesity. Its also known that maternal and paternal obesity increase the risk of obesity in the offspring and most excess weight in childhood are gained during the preschool years. Some of the evident examples come from some of the most developed nations-U.S. has 69% adults and 32% kids either in the obese or overweight range; Western Europe exbibits some of the highest obesity/overweight rates and data from the ‘National Child Measurement programme’ (NCMP) shows that more than one in five kids in England are now obese/overweight by the time they are enrolled in primary school and the rates increase further to one in three by the age of 6. To make things worse, 8% of infants and toddlers display weight ranges above 95th percentile in the U.S.A. This is indeed a nightmare as obesity/overweight that’s prevalent in these tender years is sure to linger past adolescence and well into adulthood.
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Childhood Obesity
Staying above recommended weight ranges since childhood puts the kid at a potential risk for comorbid conditions such as diabetes, cardiovascular problem and even cancer. We have a good number of research done on the risk factors of obesity during childhood years such as children’s eating habits, infant feeding practices and television viewing but what we need exactly is to understand the factors present in both parents and offspring that promote obesity across early life stages (right from preconception through prenatal period to infancy to the tender age of 2). Though researchers focus on risk of obesity through childhood and adolescent years we have evidence showing that the foundation for inappropriate weight gain is laid in early years of life by actions and interactions that can have biological and behavioural consequences. Such influences on obesity and risks for it are linked across generations-from parent to child. An understanding of various processes and sewing them together in the right order helps us focus on the generation link that’s evident.

The intrauterine environment shapes the trajectory of weight gain and after birth the teachings of parents and families combined with the socioeconomic environment has greater impact on the weight trajectories of infants and toddlers. Obesity rates of kids greatly vary depending on where they live.

Seeds of Obesity Sown Even Before Deciding to Plant
Preconception: The risk of obesity in the next generation starts even before conceiving. Until sometime back most studies focused on maternal influence of obesity on the offspring but recently even the paternal involvement in determining offspring’s health has now been taken into consideration.

The major factors affecting offspring include a mother’s birth weight, obesity and nutritional status throughout her life. Pre-pregnancy obesity rates have steadily increased since the last decade to the present one and statistics show that mothers who are overweight/obese before pregnancy are at an increased risk of having children who are large for gestational age at birth compared to their normal weight counterparts. A study by Whitaker et al. showed that maternal obesity during the first trimester of pregnancy doubled the risk of childhood obesity at 2 years of age. Fathers affect embryonic development through genetic and epigenetic mechanisms. Epigenetic changes affect the fetus’ metabolism which is primarily due to variations in the dad’s diet. This shows that paternal lifestyle behaviour definitely puts future kids at risk of obesity and obesity-related outcomes. These epigenetic changes could even be inherited by the developing sperm. All this clearly show one thing-the world that’s been monopolizing the attention to women who plan to conceive must also consider the health of men. A number of suggestions have been proposed for women in their reproductive years right from nutritional guidance to weight management. They are advised to take supplements that include multivitamins and folate to avoid deficiencies such as neural tube defects and likewise. A survey showed that 77% women opted for enrolling in a program that promoted effective lifestyle intervention before conceiving and this shows that women are on the right track. Men should also be encouraged to take care of their health. Actually, both men and women must be motivated to stay within normal weight ranges right from adolescence to help the future generation to stay at a minimal risk of obesity.

Prenatal influence: The environment affects us in many a way. Environmental exposure and timing of exposure to different factors within the environments produce interactions that are biologically seeded in the developing child. Epigenetic influence do exist and the gene sequence cannot be modified but we can indeed change the gene expression in response to environmental cues. For instance, changes to the placenta made as a result of maternal stressors or nutritional status prevails as the mediator between the developing child and the environment. This prevails as the trailer for the fetus before the main picture is shown (when the fetus then becomes a newborn). The fetus becomes adapted to epigenetic changes which then regulate behaviour, obesity and glucose tolerance. But when the fetus is small for gestational age during development or there was restricted intrauterine growth the growing newborn is at a greater risk of suffering during later stages in life.

When metabolic pathways, hormonal signalling and glucose metabolisms change by a greater margin during pregnancy it increases the risk of larger birth size and higher percentage of body fat at birth. The gut bacteria also play a critical role as researchers have come up with differences in the microbiome of overweight individuals compared to normal-weight people. The same is also seen in pregnant women and hence, might be transferred to the child too (as the child gets the microbiome composition from mother during birth through the birth canal and it’s also affected by the mode of delivery) thereby resulting in intergenerational transfer of obesity.

Maternal Lifestyle: Time and again gynaecologists insist on a healthy maternal weight gain and lifestyle behaviours to deliver a healthy offspring. Eating, physical activity and smoking levels during pregnancy have a strong impact on the risk of obesity for the fetus developing inside the mother’s womb. Besides preconception obesity gestational weight gain (GWG) changes the pregnant woman’s metabolism leading to higher risk for dyslipidaemia, glucose intolerance and insulin resistance. Such GWG leads to a greater percentage of offspring born with higher birth weight, increased body fat during the neonatal period and greater adiposity all though childhood and adulthood as well. All this is due to increased nutrition transfer from overnourished mothers to the developing fetus.

Moms pass on food likes and dislikes to the developing fetus. The food that she consumes, her tastes and smelling traits that are present during fetal development strongly influence a child’s preferences for food and flavour. Now we can understand why our little ones love sweets, hate certain vegetables and relish certain foods more than others. Performing physical activity regularly during pregnancy helps the woman deliver infants that are smaller than the ones born to women who don’t exercise. Different studies come up with different results and hence reviews are inconclusive. Another important factor affecting fetal weight is smoking status of the pregnant woman. Smoking, both maternal and paternal, during the prenatal period is strongly linked to obesity development in the offspring during childhood and adulthood.

Numerous systemic reviews and meta-analysis of data show that maternal pre-pregnancy weight gain is linked to an increased risk of overweight/obesity in the offspring, children born to moms after weight loss were only at a 35% risk of overweight/obesity compared to 60% risk in kids born to moms who remained obese, according to a study. A recent systemic review showed that 19 of 21 studies supported increased risk of childhood overweight in kids when moms experienced GWG. Kids of women who gained excessive weight during pregnancy were at a 4-times higher risk of being overweight at age 3 compared to kids whose mothers gained inadequate weight according to a study by Oken et al. A population-based cohort study proved that compared to infants of women who gained 8-10 kg of weight during pregnancy those of women who gained more than 23 kg were about 2.5 kg heavier at birth.

Factors Affecting Obesity Risk Up to 2 Years of Age: Infant birth weight is a strong determining factor of obesity/overweight risk in the child. Kids born either too small or big for gestational age are at an increased risk of overweight, obesity, metabolic disorders and cardiovascular diseases. The birth weight of the child is determined by the maternal weight at conception and GWG. As in adults, infants too should gain a definite weight in a definite period and accelerated weight gain occurring during the first 4 months of life are related to obesity at 7 years of age and a 60% increase in risk if weight gain happens within the first 2 years of life. but the reason behind rapid weight gain during this period is due to genetic factors, epigenetic processes, differences in placental leptin levels and the infant’s gut microbiome composition.

Infant-feeding habits: Kids depend on their parents for making the right decisions up to a certain age and food habits are one of those. What and how much food parents feed their infants directly affect the weight gain and obesity risks of child during later stages in life. There are not any recommended dietary guidelines for kids younger than 2 years of age to help parents and caregivers choose the right portions and foods to feed the kids. Infants are blessed with the knowledge to know how much to eat, when to eat and when they are full. They self-regulate their needs even while breastfeeding choosing how much to drink how often. That’s why infants fed on formula by parents gain more weight maybe due to the amount and pattern of feeding and so do infants who start weaning early in life. The child’s ability to self-regulate narrows down when it is dominated more and more by parental intervention.

Sometimes, parents feeding practices also depend on the child’s food choices which is affected greatly by its exposure to sweet and sour taste during prenatal exposure to the mother’s diet but they can be modified by repeated exposure to certain foods by the parents. Some parents also use feeding as a mechanism to soothe infants and such practices lead to unintentional weight gain in kids. Our lifestyle and sedentary behaviour also hold greater influence on obesity risks. The present world encourages the use of car seats and strollers that make the children idle, exposure to television starts right from their 3rd month sometimes and many suffer from lack of sleep due to increased screen time. A prospective cohort study on more than 900 infants showed that those who slept for less than 12 hours doubled their odds of becoming overweight by age 3 compared to others. An infant’s birth weight and rapid weight gain during the first months of life are clear cut indicators of future obesity risk. Hence, it does show that the way parents and caretakers feed infants and the steps that they take to engage children do affect the risk of long-term weight gain in these little ones.

In recent years, more attention has been focused on interventions targeting parents and modifiable risk factors that prevent obesity and promote healthy growth in the first 1000 days of life. Lifestyle and nutrition practices followed through life-before conception, time spent in utero and the following months after birth greatly affect the child’s weight at birth, during childhood and well into adulthood. Women who take care before conceiving, while pregnant and even after childbirth have greater chances of giving birth to and nurturing kids who are at a minimum risk of obesity in life. Nutritional interventions by parents, the steps they take to ensure kids’ exposure to healthy food and their participation in physical activity plans with the children do indeed help in making the kids as healthy as possible. It would be beneficial for both the kid and the mother when the woman strives for a healthy weight before pregnancy, abstains from smoking, strives for a normal weight gain during pregnancy, breastfeeds unless there is some health issue linked and takes care that infants get the desired sleep time during the first few years of life.

References
Preventing Obesity Across Generations: Evidence for Early Life Intervention: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5305001/

Prevention of Overweight & Obesity in Early Life: https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/prevention-of-overweight-and-obesity-in-early-life/F9BB50517A0A0F9D4F542276A30926D5/core-reader

The Effect of Early Life Factors & Early Interventions on Childhood Overweight & Obesity: https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/prevention-of-overweight-and-obesity-in-early-life/F9BB50517A0A0F9D4F542276A30926D5/core-reader

Preventing Childhood Obesity: Early Life Messages & Epidemiology: https://onlinelibrary.wiley.com/doi/full/10.1111/nbu.12277

Prenatal & Early Life Influences: https://www.hsph.harvard.edu/obesity-prevention-source/obesity-causes/prenatal-postnatal-obesity/

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