Factors that predict obesity by adolescence revealed
October 16, 2019
Science Daily/Murdoch Childrens Research Institute
Three simple factors that predict whether a healthy weight child will be overweight or obese by adolescence have been revealed in a new study led by the Murdoch Children's Research Institute (MCRI).
The research shows three factors -- a child's and mother's Body Mass Index (BMI) and the mother's education level -- predict the onset or resolution of weight problems by adolescence, especially from age 6-7 years onwards.
Each one-unit higher BMI when the child is aged 6-7 years increased the odds at 14-15 years of developing weight problems by three-fold and halved the odds of resolution.
Similarly, every one-unit increase in the mother's BMI when the child is aged 6-7 years increased the odds at 14-15 years of developing weight problems by 5 per cent and decreased the odds of resolution by about 10 per cent.
Mothers having a university degree was associated with lower odds of a child being overweight and obese at ages 2-5 years and higher odds of resolving obesity issues by adolescence.
Study author MCRI's Dr Kate Lycett said the prevalence of being overweight/obese at the age of 14-15 years was 13 per cent among children with none of these three risk factors at age 6-7 years, compared with 71 per cent among those with all risk factors.
Dr Lycett said identifying these three factors may help clinicians predict which children will develop and resolve excess weight with about 70 per cent accuracy.
"In the case of BMI, it is an objective measure that is easily measured and reflects diet and exercise choices, but is free from the challenges of assessing physical activity and diet in a standard clinical appointment such as recall bias," she said.
The findings, published in the latest edition of the International Journal of Obesity, also found children who are overweight or obese at 2-5 years have a low chance of resolving their weight problems by adolescence when these three risk factors are present.
Data was sourced from 3469 participants at birth and 3276 participants at kinder from the Longitudinal Study of Australian Children. The child's height and weight were measured every two years.
Dr Lycett said until now most studies have overlooked the important questions around which children are likely to become overweight/obese and how it be resolved.
"Because clinicians haven't been able to tell which children will grow up to become teens with excess weight, it's been hard to target interventions for those most at risk," she said.
"The consequences of this are dire, with childhood obesity predicting premature death and being implicated in cardiovascular disease, diabetes and cancer."
The study examined how combinations of 25 potential short clinical markers such as time breastfeeding and amount of outdoor activity at various ages predict weight issues, as well as resolution, by ages 10-11 and 14-15 years.
Intriguingly, short questions about poor diet, low physical activity and other common lifestyle factors were not predictive of weight outcomes.
Lead author Professor Markus Juonala, from the University of Turku in Finland, said a simple risk score, which would be easily available to child health clinicians, could help target treatment or prevention.
"Combining data on these three easily obtainable risk factors may help clinicians make appropriate decisions targeting care to those most at risk of adolescent obesity," he said.
"The benefits of removing a focus on those unlikely to need clinical interventions for obesity has largely been ignored, despite an increasing policy emphasis on avoiding wasteful or unnecessary health care."
https://www.sciencedaily.com/releases/2019/10/191016094911.htm
Offering children a wide variety and large quantities of snack food encourages them to eat more
Less focus on plate size and more on reducing quantity and variety of food key to getting children to snack less
July 19, 2019
Science Daily/Murdoch Childrens Research Institute
Offering children a wide variety and large quantities of snack food encourages them to eat more - and may contribute to weight problems, a new study has found. The research also found that how snacks are presented (in a large or small container) has little influence on how much children snack.
A new study has found that offering children a wide variety and large quantities of snack food encourages them to eat more -- and this practice may be contributing to Australia's weight problem.
The research*, led by the Murdoch Children's Research Institute and published in the latest International Journal of Obesity, also found that how snacks are presented (in a large or small container) has little influence on how much children snack.
Lead researcher Dr Jessica Kerr said their study found children weren't greatly affected by container size, with food consumption mainly driven by the quantity/variety of snacks on offer.
"There has been a popular push by nutritionists and public health officials towards replacing large dishware with smaller versions to nudge people towards healthier decisions," she said. "But we have found dishware size has very little effect on the amount of food consumed."
Dr Kerr said while the overconsumption of snack foods is an important contributor to obesity, most people do not recognise the impact it has on their calorie intake.
"Children and adults should only consume energy-dense snacks occasionally -- they do not need to be part of daily energy intake," she said. "But the reality is that Australians typically get around 30-40 per cent of their energy intake from snack foods."
Dr Kerr said three times as many children in Australia are now overweight or obese compared to 30 years ago.
"About 20 per cent (1 in 5) of children are overweight or obese," she said. "There are many complications of children being overweight such as type 2 diabetes, orthopaedic and respiratory disorders, liver problems and sleep apnoea."
Dr Kerr said until now studies into snacking behavior were limited by self-reported data or small sample sizes.
"Past dietary studies have mostly focused on main meals," Dr Kerr said. "It is important to determine on a larger scale how dishware size and the quantity, variety, and energy density of snacks affect both child and adult snacking behavior when apart from each other outside of the family environment," she said.
For the study, participants ate during a 15-minute snack break between 20 other health assessments at the Child Health CheckPoint, which looked at the health of 1800 children, aged 11-12 years, and their parents across a variety of factors from physical activity to sleep.
The children and parents were given a snack box containing non-perishable items such as crackers, cheese, a muesli bar, biscuits, a tub of peaches and chocolate.
The quantity/number and variety of snack food items and the container sizes that the food was presented in varied. Children and parents ate separately and at different times.
Researchers recorded how much food each child and parent left in the box uneaten, and calculated the total grams and kilojoules consumed.
"Children who were offered more snack items consumed considerably more energy and a slightly higher food mass. Manipulating box/container size had little effect on consumption," she said.
The impact on adults was little, however Dr Kerr said adults were more aware that they were being observed and this may have impacted their eating behaviour.
Dr Kerr said further research should be done with parents and community leaders to better understand the use and purpose of snack food items in the face of time pressures, marketing, and child preferences.
"Although there is sometimes a place for snack items to bridge the gap between main meals, our results reinforce calls to educate parents and schools about appropriate snack items and amounts of food to offer children," she said.
"Our research indicates that more attention and resources should be directed to toward offering children smaller amounts of food and, specifically, fewer and less variety of energy-dense foods and pre-packaged items. Interventions should not solely invest in reducing dishware size in the expectation that this will lead to reduced intake of snack foods."
https://www.sciencedaily.com/releases/2019/07/190719105511.htm
Supervised fun, exercise both provide psychosocial benefit to children with obesity
July 2, 2019
Science Daily/Medical College of Georgia at Augusta University
A program with clear rules, routines and activities, attentive adults and a chance to interact with peers appears to work as well at improving the quality of life, mood and self-worth of a child who is overweight or obese as a regular exercise program, researchers report.
While regular exercise is clearly beneficial to children -- and adults -- the psychosocial health of children may benefit as much from other kinds of adult-led after school programs, Medical College of Georgia researchers report in the journal Translational Behavioral Medicine.
"For me the take-home message is yes, exercise has many wonderful benefits but some of that is because you are in a program run by caring adults," says Dr. Catherine Davis, clinical health psychologist at MCG's Georgia Prevention Institute and the study's corresponding author.
They looked at 175 predominantly black children ages 8-11 who had overweight or obesity and were previously inactive. Children participated in either a fun-driven aerobic exercise program or a sedentary after-school program where they played board games and did artistic activities.
The investigators hypothesized that they would find that the exercise intervention would be more effective at improving quality of life, mood and self-worth than the sedentary program.
They found instead that, while the exercise program had the additional benefits of reducing body fat, improving fitness, and even improved brain health, there was no mood advantage from the exercise program. Fatness and fitness did not change as much in the sedentary group.
In fact, in the case of the boys, those in the sedentary group reported depressive symptoms actually decreased more over time than their peers in the exercise group.
About 10 percent of children in both groups had symptoms indicating depression at the start of the study. Depressive symptoms in children include things like a sad mood, interpersonal problems and inability to feel pleasure.
Among participating girls, depressive symptoms yielded similar improvements whether in the exercise or sedentary group, says Celestine F. Williams, senior research associate at the Georgia Prevention Institute and first author on the study.
Those sex differences might be attributable to males in the sedentary group not being under the pressure they may feel to participate and succeed in physical activities, and finding instead an opportunity to pursue more artistic and social endeavors, which children of this age tend to prefer, the investigators write.
Countless studies, including some led by Davis, have shown that regular physical activity in children who are overweight or obese and inactive can yield a variety of benefits, including reducing fatness, improving fitness and insulin sensitivity -- which reduces the risk of diabetes and other maladies -- as well as perhaps less obvious benefits, like improved cognition and improved brain health, and reduced anger and depression.
This time Davis and her colleagues wanted to more directly compare the impact of an exercise program versus a similar sedentary program on the psychosocial wellbeing of these children. While there are often control groups in this type of study, most compare the exercise program to either no program, or a less interactive and fun program. Davis and Williams agree that likely was a big part of the differences they found this time.
All the children were evaluated for depressive symptoms, anger expression, self-worth and quality of life right before starting and after finishing either arm of the study. Depressive symptoms and quality of life were measured again about a year later.
In the exercise program, the instructor led fun aerobic activity for 40 minutes daily based on the interests and abilities of the children. Rather than time on a treadmill, for example, there were more entertaining strategies to get and keep the heart rate up like a version of the age-old game tag. Children wore heart rate monitors and were rewarded for an average heart rate above 150 beats per minute during the exercise -- the average resting heart rate for an 8-year-old is 70 to 110 beats per minute -- and they got more points for a higher average.
In the other group, children participated in instructor-led activities like board games, puzzles, arts and music, and were rewarded for participation and good behavior. There were arts and crafts, challenging games like the strategy board game Connect 4, guitar music and singing popular songs, and the children were rewarded with points for being nice and cleaning up behind themselves. The children were free to talk with each other as long as it was not disruptive, which was probably a highlight for the boys, Williams says.
Relationships the children built with each other over the course of both programs likely were beneficial in elevating their mood and quality of life, Williams says. The sedentary program may have given children more time to talk with each other and develop friendships with little competitive pressure.
Other investigators have shown that children in the 8-11 age range may actually prefer just talking or socializing with their friends as a fun activity, rather than some form of exercise, while younger children may think it's more fun to run around, Williams says.
The fact that both programs provided psychosocial benefit to the children led the investigators to conclude that some benefits of exercise found in previous studies, including Davis', resulted from the regular opportunity to be with attentive adults who provide behavioral structure. It also resulted from the children enjoying interacting with each other, sharing snacks and other activities, while spending less time watching television.
Rates of obesity among children and the adolescents in this country have more than tripled since the 1970s, according to the Centers for Disease Control and Prevention, and currently about 1 in 5 school-age children and young people has obesity. Young blacks are disproportionately affected in this country.
There is plenty of evidence that obesity and overweight can impact overall quality of life and that children with these conditions can have increased problems with anxiety, bullying, fatigue, anger and general behavior problems, and that generally higher BMI, or body mass index, a ratio of weight to height, is associated with a lower self-worth in children.
"Exercise is very well demonstrated to improve mood. However, I think you have to consider exercise in the context that it occurs, so the social context counts too," says Davis.
https://www.sciencedaily.com/releases/2019/07/190702112657.htm
Even in young children: Higher weight = higher blood pressure
June 13, 2019
Science Daily/European Society of Cardiology
Overweight four-year-olds have a doubled risk of high blood pressure by age six, raising the hazard of future heart attack and stroke. That's the finding of a study published today in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC).
"The myth that excess weight in children has no consequences hampers the prevention and control of this health problem," said study author Dr Iñaki Galán, of Carlos III Health Institute, Madrid, Spain. "Parents need to be more physically active with young children and provide a healthy diet. Women should shed extra pounds before becoming pregnant, avoid gaining excess weight during pregnancy, and quit smoking, as these are all established risk factors for childhood obesity."
According to the World Health Organization, childhood obesity is one of the most serious public health challenges of the 21st century. The problem is global and the prevalence has increased at an alarming rate. In 2016, more than 41 million children under the age of five were overweight.
This study, based on the ELOIN cohort, examined the link between excess weight and high blood pressure in 1,796 four-year-olds who were followed up two years later. Blood pressure was measured at both time points, as was body mass index (BMI in kg/m2) and waist circumference.
Compared to children maintaining a healthy weight between ages four and six, those with new or persistent excess weight according to BMI had 2.49 and 2.54 higher risks of high blood pressure, respectively. In those with new or persistent abdominal obesity, the risks for high blood pressure were 2.81 and 3.42 greater, respectively. Children who lost weight did not have an increased risk of high blood pressure. The findings applied to all children regardless of sex or socioeconomic status.
"There is a chain of risk, whereby overweight and obesity lead to high blood pressure, which heightens the chance of cardiovascular disease if allowed to track into adulthood," said Dr Galán. "But the results show that children who return to a normal weight also regain a healthy blood pressure."
The best way to maintain a healthy weight and lose excess kilos is to exercise and eat a healthy diet, said Dr Galán. In addition to the central role of parents, the school curriculum needs to include three to four hours of physical activity every week. Teachers should supervise activities during breaks, while schools can offer games and sports after classes and provide nutritionally balanced meals and snacks.
Doctors should routinely assess BMI and waist circumference at early ages, added Dr Galán. "Some paediatricians think the harms of overweight and obesity begin in adolescence but our study shows they are mistaken," he said. "We need to detect excess weight as soon as possible so the damaging impact on blood pressure can be reversed."
Overweight children should have their blood pressure measured. Three consecutive elevated readings constitute high blood pressure. In young children, the most common cause is excess weight, but doctors will rule out other reasons such as heart defects, kidney disease, genetic conditions, and hormonal disorders. If the cause is overweight, more activity and dietary improvements will be advised. If lifestyle changes don't help, blood pressure lowering medication may be prescribed.
Dr Galán noted that overweight in children is most accurately assessed using both BMI and waist circumference. In the study, using either measurement alone would have missed 15% to 20% of cases.
https://www.sciencedaily.com/releases/2019/06/190613095224.htm
Physical inactivity proved risky for children and pre-teens
June 4, 2019
Science Daily/Université de Genève
At what age do children lose the desire to exercise? Researchers (UNIGE) followed 1,200 pupils and found out that from the age of 9, the positive reasons for exercising begin to be replaced by displaced incentives: to get a good mark or improve your image with others. These results call for a more detailed analysis of how PE is taught in schools to counter physical inactivity leading to a sedentary lifestyle from an early age.
Cardio-respiratory capacity in children has dropped by 25% in 20 years, according to a study by the University of Adelaide in Australia. There are multiple reasons for this, from the social environment and the decreasing number of play areas to a more academic approach towards teaching physical education and the spread of new technologies. But at what age do children lose the desire to exercise? Researchers from the University of Geneva (UNIGE), Switzerland, followed 1,200 Geneva pupils, aged 8 to 12, for two years. The team found out that from the age of 9, the positive reasons for exercising -- it's fun and good for your health -- begin to be replaced by more displaced incentives: to get a good mark or improve your image with others. These results, which are published in the journal Psychology of Sport and Exercise, call for a more detailed analysis of how PE is taught in schools to counter physical inactivity leading to a sedentary lifestyle from an early age.
Society today is characterized by an increasingly sedentary way of life and a decline in physical activity, which is reflected in the growing number of overweight children (16% of children aged 6 to 12 in Switzerland). In an earlier study, UNIGE researchers noted that the recommendations issued by the World Health Organisation (WHO) for the amount of exercise undertaken by school-age children were not being met, namely: children should be active for at least 50% of the time devoted to physical education lessons in primary school. In reality, they move on average only 38% of the time. And as children grow older, the percentage drops. Why?
Positive motivations decline as the child grows older
The UNIGE researchers tracked 1,200 Geneva pupils aged 8 to 12 for two years. The children had to complete a questionnaire every six months to measure their motivation levels according to a seven-point scale based on different motivational controls related (or not) to practising the actual activity: enjoyment, learning, health, grades, satisfying other people, integration, avoiding guilt or shame, and so forth. "Our results showed for the first time that there is a sharp drop in positive motivations for physical activity (with good motivational qualities), such as pleasure or health, over a child's time at primary school from age 9 onwards," explains Julien Chanal, a researcher in the Psychology Section of UNIGE's Faculty of Psychology and Educational Sciences (FPSE). "And we've never observed this decline at such a young age!" On the other hand, motivations considered counterproductive (with poor motivational qualities) -- such as undertaking the activity to get a good grade or to send a positive image to one's classmates -- increase as a child gets older. "It's true that harmful motivations do also mean that a child is physically active but these motivational qualities are only positive in the short term, which is counter-productive for a child's physical development. In fact, we know that if children are motivated by good reasons when they're young, then they'll remain active when they're adults," continues Chanal. But what can be done to fight against the early decline of positive motivations?
Reforming education to increase physical activity
Given that nine years is a crucial age to establish good, healthy and long term physical activity, the way PE is taught at primary school needs to be analysed, since compulsory education is the only place where every child can be reached. "In recent decades," says Chanal, "PE teaching has changed enormously. Classes are more academic, with children learning about rules, motor functioning, mutual support, etc." But this approach has a direct cost for the child since it reduces the actual time dedicated to moderate to vigorous physical activity, which is already rare outside school.
The UNIGE researchers are now working with the Haute École Pédagogique in the canton of Vaud (HEP Vaud) on teaching physical education in primary classes. The aim is to develop autonomy and cooperation among pupils, and to work on the curriculum, course structure and teacher involvement to help them keep or boost their positive motivations for physical education. "Now that children don't move as much as before outside school, it's vital that the periods earmarked for PE maximize the time they spend moving," adds Chanal. "This is especially the case since, once again, we fall below the standards prescribed by the WHO. Their recommendation is 150 minutes of physical education per week, while students in Geneva only have 135 minutes available, or three periods of 45 minutes each." Teaching physical education has an important role to play in this new global health problem, which affects children at a younger age.
https://www.sciencedaily.com/releases/2019/06/190604131231.htm
Being teased about weight linked to more weight gain among children
May 30, 2019
Science Daily/NIH/Eunice Kennedy Shriver National Institute of Child Health and Human Development
Youth who said they were teased or ridiculed about their weight increased their body mass by 33 percent more each year, compared to a similar group who had not been teased, according to researchers at the National Institutes of Health. The findings appear to contradict the belief that such teasing might motivate youth to change their behavior and attempt to lose weight. The study was conducted by Natasha A. Schvey, Ph.D., of the Uniformed Services University of the Health Sciences in Bethesda, MD, and colleagues at NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development and National Institute of Diabetes and Digestive and Kidney Diseases. It appears in Pediatric Obesity.
The study involved 110 youth who were an average of 11.8 years of age when they enrolled. The participants were either overweight (defined as a body mass index above the 85th percentile) when they began the study or had two parents who were overweight or obese. At enrollment, they completed a six-item questionnaire on whether they had been teased about their weight. They then participated in annual followup visits for the next 15 years.
The researchers found that youth experiencing high levels of teasing gained an average of .20 kg (.44 lbs) per year more than those who did not. The authors theorize that weight-associated stigma may have made youths more likely to engage in unhealthy behaviors, such as binge eating and avoiding exercise. Another possible explanation is that the stress of being teased could stimulate the release of the hormone cortisol, which may lead to weight gain.
https://www.sciencedaily.com/releases/2019/05/190530101213.htm
Gut microbiota of infants predicts obesity in children
October 23, 2018
Science Daily/American Society for Microbiology
Evaluating the gut microbiota of infants may help identify children who are at risk for becoming overweight or obese. The research revealed that gut microbiota composition at two years of life is associated with body mass index (BMI) at age 12. In addition, the BMI at age two was not significantly higher in children who later became overweight/obese, indicating that gut microbiota composition may be the earliest warning sign for detecting obesity.
"Our study provides more evidence that the gut microbiota might be playing a role in later obesity," said lead author Maggie Stanislawski, PhD, who is a research associate at the LEAD Center, University of Colorado Anschutz Medical Campus, Colorado School of Public Health, Aurora, Colorado. "If our findings can be confirmed by other studies, the gut microbiota might play an important part of the obesity prediction algorithm, to identify at-risk kids early in life, before they start to gain any excess weight that might put them at risk for later obesity."
Prior to this study, a growing body of evidence has demonstrated that the gut microbiota plays a role in obesity, and there is some evidence that the role might be causal. To shed more light on the issue, the University of Colorado researchers collaborated with Merete Eggesbø, MD, PhD, who leads the NoMIC study at the Norwegian Institute of Public Health in Oslo, and analyzed data from 165 infants who had BMI measured at 12 years.
The NoMIC study began in 2002 as one of the earliest birth cohorts in the world to investigate the early life gut microbiome and includes roughly 550 kids who are now teenagers. The study recruited moms and infants in the hospital at the time of delivery. At 12 years of age, 20% of the 165 children in the study cohort were overweight or obese.
The researchers compared the BMI at age 12 with gut microbiota samples from six time points throughout their childhood, at day 4, day 10, one month, four months, one year, and two years. They performed 16s rRNA gene sequencing on the gut microbiota samples. "We looked at whether there were specific taxa that were predictive of later BMI at each time point," said Dr. Stanislawski.
The researchers found qualitative differences in the composition of children's gut microbiota at day ten and at two years that were associated with BMI z-scores at age 12. BMI z-scores are measures of relative weight adjusted for child age and sex. They also examined how much of the variation in childhood BMI z-scores was explained by the early gut microbiota taxa.
"At the early time points, there was somewhat of a relationship between the gut microbiota taxa and later BMI, but the relationship was much stronger as the kids got older," said Dr. Stanislawski. "At one year, it was stronger than the earlier time points. At two years, it was the strongest. We found this very interesting because, at two years, there wasn't any obvious phenotype in terms of whether or not the kids were going to become obese. Kids who became obese later in life didn't have high BMI z-scores at age 2. The findings suggest that the gut microbiota phenotype was present before any overt sign of overweight or obesity. Since the gut microbiota is influenced by diet, this association could also reflect dietary choices that are precursors to obesity."
Dr. Stanislawski said the study was limited in that the entire cohort was of Norwegian descent. This research, she said, needs to be repeated in other cohorts, but if replicated, it may lead to a new tool to identify kids at risk for developing obesity. "It is better to identify at-risk kids early. It is easier to prevent obesity than to reverse it," said Dr. Stanislawski. "It's possible that if we follow up some of these findings in the lab, it will reveal more about the pathophysiology of obesity as well."
The study also exposed a potential health caution. The researchers found that some gut microbes that are generally thought to be healthy in both children and adults were associated with higher childhood BMI. This highlights that we do not fully understand the dynamics of the gut colonization process.
"When I was pregnant, my doctor suggested giving the baby probiotics every day, and I think a lot of people are giving their infants probiotics," said Dr. Stanislawski. "However, it might not be the best idea to give babies the same types of bacteria every day, particularly in very early life when overloading the gut with one or two strains may prevent colonization with other types of important bacteria." She pointed out that one way to improve the gut microbiota in kids and adults is to eat a well-balanced diet with lots of different types of vegetables and fiber, so there are lots of things feeding the gut microbiota.
Future research will focus on further examining the colonization process in relation to other markers of metabolic health in children. "We will focus on the temporal dynamics of first two years," said Dr. Stanislawski.
https://www.sciencedaily.com/releases/2018/10/181023085640.htm
Vitamin D supplements may promote weight loss in obese children
September 27, 2018
Science Daily/European Society for Paediatric Endocrinology
Vitamin D supplements may promote weight loss and reduce risk factors for future heart and metabolic disease in overweight and obese children, according to new research. These findings indicate that simple vitamin D supplementation may be part of an effective strategy to tackle childhood obesity and reduce the risk of serious health problems, such as heart disease, in adulthood.
Obesity in childhood and adolescence represents a major health problem worldwide, which leads to the development of expensive, serious and debilitating complications, including heart disease and diabetes, in later life. Although vitamin D deficiency is typically associated with impaired bone health, in recent years it has been increasingly linked with increased body fat accumulation and obesity, with the precise nature of this relationship currently under intense investigation by researchers. However, the effect of vitamin D supplementation on the weight and health of obese children and adolescents had not yet been investigated.
In this study, Dr. Christos Giannios, Professor Evangelia Charmandari and colleagues at the University of Athens Medical School and the 'Aghia Sophia' Children's Hospital in Athens, assessed 232 obese children and adolescents over 12 months, with 117 randomly assigned to receive vitamin D supplementation, in accordance with the Endocrine Society's guidelines on treatment and prevention of deficiency. Levels of vitamin D, body fat, and blood markers of liver function and heart health were assessed at the start of the study and 12 months later. The study reported that children given vitamin D supplements had significantly lower body mass index, body fat and improved cholesterol levels after 12 months of supplementation.
"These findings suggest that simple vitamin D supplementation may reduce the risk of overweight and obese children developing serious heart and metabolic complications in later life," says lead researcher Prof Charmandari.
The team now plan to investigate the effects of vitamin D supplementation on the health of obese children and adolescents that already have unhealthy conditions, such as high blood pressure, high blood glucose and high cholesterol, all of which increase the risk of heart disease, stroke and diabetes.
Prof Charmandari cautions, "Although these initial findings indicate that vitamin D could be used in the treatment of obesity, there remains a lack of evidence on the safety and long-term effects of supplementation, particularly if there is no vitamin D deficiency. However, if your child is overweight or obese I recommend that you consult your primary care physician for advice, and consider having their vitamin D levels tested."
https://www.sciencedaily.com/releases/2018/09/180927215656.htm
When it comes to children's ability to think, weight and activity level both matter
October 27, 2015
Science Daily/Medical College of Georgia at Georgia Regents University
Weight and physical activity levels are both factors in a child's ability to acquire and use knowledge, a new study finds. Children who were lean and active scored better on cognitive tests than either their lean, inactive peers or overweight, inactive children, according to the study, which provides some of the first evidence that weight, independent of physical activity, is a factor.
"The question this paper asks that has not been asked before is whether it is just fitness that influences children's cognition," said Dr. Catherine Davis, clinical health psychologist at the Georgia Prevention Institute at the Medical College of Georgia at Georgia Regents University. "What we found is weight and physical activity both matter."
Children who were lean and active scored better on cognitive tests than either their lean, inactive peers or overweight, inactive children, according to the study in the journal Pediatric Exercise Science. The study provides some of the first evidence that weight, independent of physical activity, is a factor.
The study looked at 45 normal-weight children age 7-11, including 24 who were active and 21 who weren't. Children were considered physically active if they participated in organized activities such as swimming, gymnastics, soccer or dance for more than an hour per week. Researchers corroborated this participation with an adult, and children self-reported their physical activity. The study also looked at 45 inactive, overweight children with very similar demographics, with exact matches on gender and race, and close matches on other relevant issues such as parents' marital status and education level and age to help ensure any differences were not strongly linked to socioeconomic status.
As expected, the 24 normal-weight, physically active children had a lower body mass index, or BMI, less fat and a lower resting heart rate than the overweight, inactive children.
When researchers used the well-verified Cognitive Assessment System, the advantages continued to hold. For example, comparing the active, healthy-weight group with the overweight, inactive children, the active group scored nine points higher for planning -- things such as figuring out and carrying out a strategy and using knowledge -- and eight points higher for their ability to pay attention.
Weight as an independent factor among inactive children generated an even bigger difference in the ability to pay attention, with normal-weight inactive children scoring 12 points higher. Those kinds of numbers could be the difference between a child being average in terms of his cognitive function and at the top end of the normal range, Davis said. In fact, the thinner, inactive kids scored higher on attention as well as a summary measure of cognition than their heavier peers.
Still, comparing inactive and active children who were all a healthy weight showed that activity alone clearly provided an edge, with the active children scoring higher in most areas of cognitive function, including 11 points higher for their ability to plan and seven points higher in attention.
"Activity made a difference even among normal-weight kids. That verifies that physical activity makes a difference in brain function," Davis said. The good news is that children, with the help of their families and schools, have time to make healthy lifestyle changes that will modify their weight trajectory, she said.
"These kids are still growing. If they can cut some of the empty calories out of their diet and pick up the pace on physical activity, they may grow into their weight," Davis said.
The long-time investigator of how physical activity affects overweight children was surprised that weight was an independent factor affecting cognition, acknowledging that exactly how and why is unclear. It could be excessive inflammation, hormones, both or neither, Davis said. She noted that while this study focused on weight, it's likely the amount of body fat that actually matters and overweight children in the study consistently had more fat, rather than having a higher weight because of extra muscle mass, for example.
Next steps include studies that also include overweight, active kids to see if heavier children derive as much benefit from physical activity as their normal-weight peers, and to learn more about how weight and physical activity relate to children's brain health.
Both overweight and inactivity have been independently associated with a cognitive disadvantage in children. Davis published a study in 2011 in Health Psychology that showed regular exercise improves the ability of overweight, previously inactive children to think, plan and even do math. Those who participated in 40 minutes of exercise every day after school garnered even more improvement than those who were active for about 20 minutes daily. That study also used the Cognitive Assessment System as well as functional magnetic resonance imaging, which showed those who exercised experienced increased brain activity in the prefrontal cortex -- an area associated with complex thinking, decision-making and correct social behavior. A later study comparing an after-school exercise program to an after-school sedentary program, showed better brain development in the exercise group.
http://www.sciencedaily.com/releases/2015/10/151027123906.htm