If you are a parent of baby who is large for his age, chances are your older relatives would congratulate you instead of nagging at you to get your baby’s weight up.
They will tell you that chubby babies are perceived to be well-fed and, thus, strong and healthy.
Besides, it is common thinking that the child’s baby fat will melt away when he grows up.
Yet, more and more research is saying otherwise. Fat babies are, in fact, at a higher risk of becoming overweight or obese children.
These obese children are, in turn, more likely to be obese as adults, putting them in greater danger of serious health problems such as heart disease, type 2 diabetes and cancer.
This link was underscored in a US study published last year, which tracked 10,186 children from birth to seven or eight years old.
Babies with a hefty birth weight of above 4.5kg at full term were 69 per cent more likely to be obese by the time they entered kindergarten.
This was compared with babies with an average birth weight, said researchers from the University of Virginia School of Medicine.
The average birth weight of Singaporean Chinese babies at 40 weeks is about 3.2kg.
Real danger for babies
Doctors in Singapore agree the danger is real.
Dr Yang Linqi, a paediatrician at Thomson Paediatric Centre, said higher birth weight is associated with greater body mass index in childhood and later in life. But the individual could be gaining more lean mass rather than fatty tissue, she pointed out.
The problem does not just affect babies born with high birth weights. Even smaller infants, such as those who had poor growth during pregnancy, can be at risk, studies show.
This is because they tend to pile on weight more quickly in their early months – and this leads to increased central fat deposition in their bodies, said Dr Yang.
In Singapore, there is a group of researchers studying an entire generation of babies to find out how their mothers’ pregnancies impact them as they grow up – and the researchers are also keen to uncover more about the link between babies who are large for their age, and fat adults.
Associate Professor Lee Yung Seng, head of paediatrics at National University Hospital who is involved in the study, said that it is “a simple and yet interesting question which we plan to analyse when the children are older”.
The study, termed Growing Up In Singapore Towards Healthy Outcomes (Gusto), started in 2009 and tracks the health of more than 1,000 children. The oldest child in the study is now eight years old.
A better understanding of the relationship between birth and future weight could help to address the uptrend of overweight children here.
The 11-and 12-year-olds in Singapore today are more likely to be overweight or severely overweight, compared with 20 years ago. This is based on the Health Promotion Board’s (HPB’s) height and weight screening data from 1990 to 2015.
In 2015, about four in five children who were overweight or severely overweight at seven years old remained overweight when they reached 11 or 12 years old.
In 1995, the figure was lower at about four in six children, according to the HPB figures.
A possible factor is the feeding of formula milk to infants. Dr Christelle Tan, a specialist in paediatric medicine at Raffles Specialists – Holland V, noted that overseas studies have found that formula-fed infants may be at greater risk of overfeeding and rapid weight gain and, hence, childhood obesity.
Why do fat babies stay fat?
A theory is that accelerated growth in a child’s early years has a long-term impact on the body’s hormonal feedback systems.
These systems regulate one’s weight, food intake and metabolism and can thus affect the presence of fat deposits, said Dr Tan.
Weight gain in babies is fastest in the first three months and will gradually slow down throughout the first year of life, said Dr Han Wee Meng, head of nutrition and dietetics at KK Women’s and Children’s Hospital (KKH).
On average, babies would double their birth weight at around three to four months and triple it by one year of age.
A baby who is large for his age may become a fat adult through the cumulation of excess fatness in each stage of the babies’ growing up years, said Associate Professor Fabian Yap, who heads the endocrinology service at KKH’s department of paediatrics.
The fatness of a newborn baby is a direct result of nutrition from the mother during pregnancy, and it also depends mainly on maternal factors , he said.
Subsequently, for the first six months of a baby’s life, his fatness primarily stems from milk feeding practices, added Dr Yap.
Most babies would be fully weaned to a solid-based diet by the time they turn one year old. A habitual eating pattern emerges thereafter that continues throughout his childhood and beyond.
“Maternal obesity, gestational weight gain, gestational diabetes, excessive milk feeding and delayed weaning are examples of early life factors that can lead to fat babies and infants, setting the stage for higher risk of adverse health outcomes later in life,” said Dr Yap.
Beyond infancy, a child’s dietary habits and physical activity will influence weight gain, he explained.
“These behaviours often reflect the culture and mindsets of a child’s parents and caregivers,” he added.
A version of this article appeared in The Straits Times.