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Children’s weight, weight of children. There is a lot of discussion about what a healthy weight for our children would be and what factors could influence it. Because we have already written regularly on topics about getting fit and losing weight for adults, in this article we pay more attention to the topic: healthy weight for children. We do this based on a number of scientific studies.
Children’s weight determined by parents for 40%
Recent research has shown that children’s weight is determined by 40% by the weight of the parents. The relationship is strongest in children with a high BMI.
Researchers from the University of Sussex and the London School of Economics compared the BMI of 100,000 children and their parents from six different countries. This allowed them to also take into account the different degrees of development and differences in dietary patterns.
Dietary pattern was found to have a relatively low influence while especially the weight of parents played a major role. This influence per parent would average about 20%. However, it was noted that this influence was particularly significant in cases where the child (and thus in many cases the parents) has a high BMI.
Bitter pill to swallow
Nice, but what use is this information? Earlier research has shown, for example, that it makes little sense for parents to exercise a lot for their children. This would rather increase the chances that you pass on to your child the message from the genes you give them that it needs to ‘be more efficient with energy’ and thus store more belly fat.
If there is obesity in the family, you only avoid passing it on by being more critical in choosing a partner and hoping your date doesn’t know better.
Sporty dad gets overweight child
If you want to know what happens in the body, you should have been in Phoenix, Arizona last week. There, for the seventh time, the American Physiological Society’s Integrative Biology of Exercise meeting took place. Many smart people who come together every four years to tell and learn what has been discovered in recent years. One of those people is Alexander Murashov, lecturer in physiology at East Carolina University.
There has been a lot of research into the relationship between the mother’s lifestyle before conceiving the child and the health of this child. Something I still need to address on this site (previously I wrote extensively about training during and after pregnancy, but not before). However, Murashov and his fellow researchers were curious about the relationship between the father’s activities before conceiving the child and the child’s health.
They had male rats train for 12 weeks. By training I assume the rats ran on a treadmill for a certain amount of time daily and not, for example, trained chest-biceps on Mondays, starting with a chest press. However, because I find that image funny, I’ll call this group the gym rats. They then looked at the effects in the offspring of these gym rats and compared them with the offspring of non-trained rats.
Offspring of sporty dad burns fewer calories
The results were surprising. The offspring of the gym rats were found to be able to burn calories “more efficiently.” That may sound positive. It is positive, for example, if you crash in the desert or wash up on a deserted island. Not if you want a six-pack. More efficient in this case means burning fewer calories. When both groups were given a high-fat diet, the children of the gym rats were found to have a higher weight and more often overweight. They also had reduced glucose tolerance and higher levels of insulin.
Technically speaking: the researchers examined the sperm of the gym rats and found that the expression of certain genes and miRNA was altered in the offspring. “A response to the challenges posed by the fathers’ environment,” the researchers write. Surprising, but somehow also very logical. Replace the rat with a marathon runner who trains every day. Large amounts of calories are burned every day. Somehow this information is passed on to the next generation. A bit like a pit crew noticing that they have to refuel more often than the opponents every race and coming back the next racing season with a car that consumes less fuel.
Screw Darwin
It’s another example of evolution working against you. We already have experience with the disadvantages of “too slow evolution”. Our bodies still convert carbohydrates and fats into body fat thinking that we need this storage when we already weigh 130 kilos or more. I understand that you are not happy with that as an average Westerner for whom it is a bigger challenge to skip a meal than to find the next meal. In this case, knowledge of the previous generation is quickly passed on to the next. As if someone is writing a code:
“Daddy consumes a lot of energy, child must be more efficient.”
That would be a good code if energy were indeed scarce. From a survival perspective, the primary driver of evolution, energy storage is still much more important than limiting overweight. Worldwide, millions of people are still malnourished. Appearance only becomes important when fat people can no longer find partners to reproduce with.
Don’t get angry, that’s what Darwin says.
So?
As logical as it may be, it still sucks in this case. You live healthy, exercise a lot, and then your children have to make more effort to prevent overweight. What should you do then? Stuff yourself all day on the couch until you have multiplied? “Look Darwin, much more energy is coming in than going out. Rewrite the code for the next generation.”
Unfortunately, that doesn’t work either. Research from 2014 shows that “bench rats” with overweight and diabetes before conceiving children increase the chance of overweight in their offspring. However, I can offer some small comfort. The effect of the positive influence that gym rats could have had on their offspring was not taken into account in the rats. It is not the case that their kids see them come home every day to then see them go to the gym. Nor can they expect healthier food from their sportier dad. After all, they don’t see their dad and are served a high-fat diet by the researchers. In short, this is only about nature, while the nurturing aspect after birth is not included in the research. I wasn’t there in Phoenix either. I can only assume that it’s about running relatively long distances daily. If this news only affects the men you exclusively see on the treadmill in the gym, then I don’t really mind. Finally, we will have to wait and see if research in humans yields the same results.
Healthy weight for your child? Conceive it in winter
Do you want to have a child? Maybe you should postpone the attempts until winter. Or take a trip to colder regions. If, at least, you want to lower the chance of your future offspring becoming obese.
According to new Swiss research, the temperature at the time of conception influences the likelihood of overweight in the child.
If you have followed the important discoveries about brown fat over the past 10 years, the above may not surprise you. At most, you see it as yet another proof of mammals’ ability to prepare their offspring as well as possible for the world.
Brown fat again?
First, the obligatory explanation about brown fat in case the discoveries about it have completely passed you by. From an earlier article:
White fat cells (White Adipose Tissue, WAT) are the fat cells responsible for often undesirable amounts of body fat and a high weight. Their role is to convert an energy surplus into a reserve fuel. Brown fat cells (Brown Adipose Tissue, BAT) have a very different role, aimed at regulating temperature when it drops. To increase the temperature, they ensure an increased energy consumption, releasing heat. A mechanism that in humans, especially babies, use more brown fat for protection. As we get older, the brown fat cells are replaced by white fat cells.
Although most of it disappears, it was discovered in 2009 that some remains around the spine and neck. Slim people often have more brown fat than overweight people. They are also often better able to make white fat cells behave like brown fat cells (also called ‘browning’).
For some, brown fat cells and the ability of white fat cells to ‘brown’ are the holy grail of research into obesity. This latest research shows that the influence of brown fat extends even further than previously known.
Baby fat in children
So brown fat protects babies from the cold by potentially providing higher combustion. Wouldn’t it be handy then if children in cold countries were born with more brown fat than in warm countries? Research has already shown that people in cold countries have more brown fat. But of course, you have to have it immediately as a baby, when you are at your most vulnerable. So as soon as you are born and not only when the body notices that it is very cold.
According to the research from Switzerland, the temperature during the conception of the child is a factor that drives this. Sex in cold months would conceive children with more brown fat and thus a lower risk of overweight. Further research showed that this also applies to mice conceived under low temperatures (8 degrees).
Epigenetic Changes
We have written about epigenetic changes before. These are non-permanent changes to DNA that can be passed on to offspring. For example, we previously wrote about fathers who increase the risk of their offspring developing overweight by exercising a lot (and consuming a lot of energy). If fathers consume so much energy, it might be useful for their children to consume less by default due to a lower metabolism. For some reason, this is one of the few articles I have written that my daughter regularly refers to.
Another example of epigenetic changes is the potential influence of energy drinks consumed by a man on the mental state of his future offspring.
In this case, however, it is not known how long the father must be in certain conditions before such epigenetic changes occur and can be passed on. I say father because the mother’s temperature did not make a difference in the amount of fat tissue in the offspring of the mice. In practice, this will not matter much to most people since you usually lie in the same bed when you have sex. But maybe it will be a lot less pleasant for donors in the future. Eight degrees doesn’t seem like the most comfortable temperature to get busy. The male mice also spent several days at a temperature of 8 degrees before they were allowed to warm up to a female.
So, I wouldn’t suggest taking an ice bath before sex, or sitting in the refrigerator for a while. First, because you might have to endure it for days. Second, because you usually don’t make a good impression on your partner after an ice bath.
Exercise During Pregnancy
I have written several articles about exercising during and after pregnancy. This recent research shows that exercising during pregnancy improves the metabolism of the child and reduces the chances of certain diseases. In mice, at least.
The researchers from the University of Kentucky presented their findings during the American Physiological Society’s Integrative Biology of Exercise 7 meeting in Phoenix.
Exercising during pregnancy could even be as effective in preventing “age-related” health risks as efforts made by the child themselves as an adult.
Kevin Pearson, associate professor at the University of Kentucky Department, explains:
Oxidative stress is damage to the body caused by the accumulation of free radicals, unstable molecules. The accumulated amount of free radicals reduces resistance to stress and increases the risk of obesity and age-related and chronic diseases. Reducing oxidative stress can reduce the risk of cancer, heart disease, and type 2 diabetes.
The researchers studied indicators of oxidative stress, inflammation, and insulin sensitivity in mice born to mothers who exercised during pregnancy. The offspring of these mice had better resistance to stress and improved insulin sensitivity. Even as adults, this was better than in mice born to inactive mothers.
Our findings highlight pregnancy as a sensitive period when positive lifestyle interventions could have significant and long-lasting beneficial effects on offspring metabolism and disease risk
Overweight Mothers Underestimate Child’s Weight
First, a disclaimer. This piece could be considered sexist because only the role of the mother in determining the child’s nutrition is mentioned. However, this is what the researchers focused on, and statistically, this is not unusual. In my household, it is the man who largely determines what is on the table (and yes, also the one who prepares it).
Many of us probably know an example of overweight seeming to be passed from parent to child. Less fortunate genes and/or an unhealthy relationship with food being passed on to the next generation.
Sometimes, however, you get the feeling that parents with overweight consider their child’s overweight less serious than outsiders would. Personally, I have known a young mother for years who has always struggled with significant overweight and whose daughter seemed to be heading in the same direction from a young age. There is no indication that the mother is worried about this.
I have sometimes wondered if the daughter’s weight is used by the mother as a justification for her own weight, consciously or unconsciously. To reason that it is simply the genes and not the diet that causes the weight; ‘because my daughter is also overweight’. Or that it is the same form of denial that has perpetuated their own overweight. Whatever the reason may be, the overweight does not seem to be taken seriously enough. I always consider that I am too quick to judge as a spectator. Recent research, however, seems to justify this feeling, at least in part.
Underestimation of Child’s Weight
Researchers from Washington University in St. Louis concluded based on their research that overweight mothers often underestimate the weight of their children. In January, they published their findings in the journal
Obesity Science & Practice.
For their research, they followed 230 overweight mothers in St. Louis with toddlers. Almost half of the mothers estimated the weight of their overweight children as “about the right weight.” Of the mothers with overweight children, only 20% saw it as overweight. Forty percent underestimated the weight.
Overweight Role Models
Conversely, there is also a problem. Parents are important role models for their children. Figuratively, but also literally. Earlier research has shown that children do not see their own overweight as overweight if the mother is also overweight. The more prevalent overweight is, the less it would be recognized as a problem.
Role Models in Nutrition
This is not the first study to show that mothers often misjudge the weight of their children. Previous studies have also shown that the mother often plays a significant role in setting an example regarding a normal diet. This most recent study wanted to test whether mothers could provide incorrect nutrition because they misjudged the weight. The image below is a visual representation of that hypothesis:
They did indeed see in their research that women who judged the weight correctly were more focused on preventing overweight.
Women who misjudged this were less concerned about the influence of nutrition on their children’s weight.
Teaching Children Healthy Eating
Parenting offers some classic challenges such as: “How do you teach sharing?”, “How do you make your child resilient?” and “How do you survive puberty?”. Of a more daily nature: ”
How do you teach your child to eat vegetables?”.
Common sense says:
“Let them eat what’s on the table and make sure there are vegetables in that table.”
It sounds logical, but perhaps science can provide a bit more guidance.
Richard Rosenkranz is an associate professor in nutrition, dietetics, and health at Kansas State University. In a publication for the university’s website, he offers parents some advice on teaching their children to eat vegetables.
Learning Early, Done Later
As an embryo and later as a fetus, a child receives information about the environment. Mothers can take advantage of this when it comes to developing a taste for vegetables.
Rosenkranz suggests based on research with pregnant rodents that taste begins to form in the womb. Research with pregnant women shows that women who consume food with more bitter chemical compounds (polyphenols) give birth to children who are more receptive to them. This includes vegetables like Brussels sprouts and kale. The research mainly tested how children initially reacted to eating those vegetables.
Don’t Give Up, Set an Example
Children could primarily learn through repetition and variation. For that repetition, it is important not to give up “as soon as a child frowns” when eating certain healthy foods. What is more important is whether the child is willing to eat it. Ultimately, that frown will become smaller and smaller.
In addition, babies could already determine what is normal and abnormal food from 6 months onwards. They mainly pay attention to what the parents eat. If your own meal looks very different from that of your baby, it might not be surprising that the little nose is turned up. Now, I understand that you are not going to serve spare ribs to your 6-month-old baby, but according to Rosenkranz, it can help to eat similar vegetables at least as your child. “Or sneakily eat your own meal in privacy and pretend to eat a carrot when your baby is watching,” I think.
Start with Sweeter Vegetables
Starting with sweeter vegetables like carrots and corn is the next tip since generally everyone likes sweetness. And then try broccoli and Brussels sprouts.
Another advantage of corn kernels is also that picking up the loose kernels is good practice for fine motor skills.
Don’t Force Children to Eat Vegetables
It is pointless to force your child to eat their vegetables. Nagging them to finish their plate is equally ineffective. It does not lead to a healthier eating pattern or weight, at most, an unpleasant mealtime.
I have never been a very big eater, but I cannot remember my parents ever having to nag me to finish my food. It is different for my wife. The thoughts of her father forcing her to eat vegetables are quite traumatic for her. Perhaps that is why I regularly cook two different meals; one for my daughter and myself, the other for my wife. I learned early on not to ask my wife to try something she wouldn’t eat herself.
It seems to me that you do more harm than good by nagging. Julie Lumeng of the University of Michigan comes to a similar conclusion with her recent research: It makes no difference in terms of eating behavior or weight. It only creates more tension at the table and can disrupt the parent-child relationship.
If you want your child to finish their plate, serve less.
Forcing Children to Eat Vegetables Doesn’t Work
In the study published in
Appetite, researchers attempted to answer various questions:
- What are the consequences of forcing children to eat on the child’s weight?
- What are the consequences of forcing children to eat on the child’s pickiness with food?
Does a child learn, for example, to overeat because they are always forced to finish their plate, leading to a higher risk of obesity? Or will forcing them to eat vegetables lead to a more varied eating pattern? According to the researchers, there were arguments for both scenarios, but neither turned out to be true.
During the year of observation, children’s weight remained stable, whether they were picky eaters or not. There was also no correlation found between compulsive eating of various foods and pickiness with food.
Picky Eaters
According to Lumeng, English-speaking ‘appetite scientists’ have had some trouble with the word ‘picky’. They now prefer terms like ‘choosy’ or ‘selective’.
Adults, she says, are not called ‘picky’, but children are treated according to a different standard. That is unfair, she argues, because taste is partly encoded in our DNA. Regardless of age, this is largely beyond our control and unchangeable. That is the main message. I think the Dutch term ‘kieskeurig’ has less negative connotations than ‘picky’.
This pickiness mainly appears to be an irritation and discomfort for parents. It is rare that one needs to fear malnutrition in general or a shortage of specific nutrients. Therefore, it is not worth making such a big deal out of it.
Positive Reinforcement Instead of Nagging
These findings are not new, and Lumeng refers to 10-15 years of research that largely show the same result.
If parents do want to encourage certain eating behaviors, they should do so in a way that strengthens the bond with the child. Small, easy changes implemented in a fun way.
I also wrote an article with tips on how to teach children to eat vegetables based on an American study. Those tips are in line with this recent research. However, the earlier article provides tips on teaching children to eat vegetables at an earlier age and how to do it in a fun way.
The Spongebob Effect
At the end of last year, I wrote about a ban on cartoon characters on the packaging of unhealthy food. The food industry trying to lure children into their candy house. However, I pointed out that parents play a big role in this because they want to make their children happy with these kinds of products. However, you can also ‘tempt’ your child to eat healthy food this way. Win-win.
Rosenkranz also suggests that children are more likely to eat their vegetables when they are cut or arranged in the shape of fun faces or animals.
Masterchef Junior
Children should be involved in food preparation from the toddler years. Their responsibilities in the kitchen should grow with them. Rosenkranz refers to research that shows a direct correlation between the amount of food a person prepares themselves and the amount of vegetables they eat. Also, helping to choose vegetables in the store can help, or even better, helping to grow them. Not everyone has a vegetable garden, however.
‘Snackable’ Vegetables for Teens
Vegetable consumption apparently decreases as children get older, with a low point in adolescence. Rosenkranz’s solution to this is to make vegetables snackable.
one way to increase teenagers’ vegetable consumption is to provide fully prepared vegetables in easy-to-access places. For example, parents could make sure a vegetable tray with dip is sitting on the counter when teens come home from school, or they could have a grab-and-go vegetable conspicuously placed in the refrigerator.
Less Traditional
No, the American associate professor did not specifically address the Netherlands. That last tip is from me personally.
There are many different ways to eat vegetables. I used to have a typical aversion to Brussels sprouts. Not anymore. Not because I learned to eat them, but because I learned to prepare them. And the same goes for some other vegetables. In the past, I would get whole Brussels sprouts on my plate with a little salt and pepper, some potatoes with gravy, and a meatball. I still don’t want that. However, in smaller pieces in a tasty casserole is a different story. Does your child not like Brussels sprouts, or does your child not like your Brussels sprouts?
Moreover, there is now more variety of vegetables in stores, so the only limitation is your own creativity. According to advertisements, even mashed potatoes are not what they used to be. At least, if we can believe that annoying child who never gets anything to eat at home. Take your child to the store and have a fun vegetable hunt.
Grandparents Make Children Overweight
The old tradition of grandparents spoiling their grandchildren turns out to be less innocent than you might expect. A study from the University of Glasgow shows that grandparents, among other things, have a bad influence on their grandchildren’s weight.
These findings reach me just in time. It’s Thursday 12:00 when I write this, so that means my son or daughter-in-law could be at my door with my granddaughter at any moment. Every Thursday and Friday, my wife and I take care of our granddaughter. They’re a bit late today, though. It wouldn’t be because her parents are alarmed by the outcome of the recent British study, would it? I hope my background in fitness gives them enough confidence that we won’t turn that little girl into a smoking couch potato with overweight.
The researchers at Glasgow conducted a systematic review, comparing the outcomes of previous studies on the influence of grandparents [1]. After an initial selection of over 5600 studies, 56 suitable studies from 18 countries remained after filtering for suitability and duplicates. The ultimate goal was to determine the influence grandparents had on cancer risk factors. For this, the researchers looked at the influence on diet, weight, level of activity, and whether smoking occurred in the presence of grandchildren.
Grandparents’ Influence on Upbringing
Taken together, grandparents did not fare too well in the comparison. The diet, level of activity, and weight of the grandchildren were negatively affected.
Of the 26 studies on the influence on diet, only one showed a positive effect. There were 11 studies that showed a negative effect and four studies that showed no effect or a negative effect. The remaining studies showed either no effect or significant differences in effect among participants.
The effect on weight was more consistent. Grandparents had the greatest influence on this, in a negative way. No study showed a positive effect, while eight studies showed a negative effect. Seven other studies showed a negative effect, no effect, or significant differences in effect.
Regarding the influence on the level of physical activity, the studies were less clear. However, in most studies where a significant effect was found, a negative effect was shown. Only one study showed the positive effect of grandparents, for example by taking children to sports clubs and encouraging them during sports.
As for smoking, 9 out of 16 relevant studies showed a negative effect, while three other studies showed different or negative effects. This includes grandparents smoking in the presence of the child, but also the role model effect by smoking in the child’s sight. In some studies, the grandfather was especially the culprit, while in a single study, the arrival of the child led to less smoking (in general or specifically in the child’s presence).
“A Pause in Parenting”
Based on any individual study you pick out, you could come to any possible conclusion. By lumping them all together and comparing them, however, you can discover trends. Such as the trend that the tradition of the spoiling grandparent is not as innocent as you might expect. Besides the need to spoil, grandparents (according to parents) may also know less about healthy eating. In that respect, of course, I endorse the possible exceptions.
Parents also seem to find it difficult to address grandparents about this. Among other things because they may depend on them for childcare. It is understandable that it can be difficult to discuss, then. However, depending on the frequency of babysitting, it may sometimes be necessary. You may have great ideas about a healthy upbringing, but in some cases, you will still have to delegate them. If you visit grandparents once every few months, a small “pause in parenting” will not be disastrous. However, if grandparents determine half the week’s dinner or lunch every day, it’s convenient to coordinate what the diet should look like.
References
- Peter Dolton, Mimi Xiao, The intergenerational transmission of body mass index across countries, Economics & Human Biology, Volume 24, February 2017, Pages 140-152, ISSN 1570-677X, http://dx.doi.org/10.1016/j.ehb.2016.11.005.
- sciencedaily.com/releases/2016/11/161104120456.htm
- S.-F. Ng, R. C. Y. Lin, C. A. Maloney, N. A. Youngson, J. A. Owens, M. J. Morris. Paternal high-fat diet consumption induces common changes in the transcriptomes of retroperitoneal adipose and pancreatic islet tissues in female rat offspring. The FASEB Journal, 2014; DOI: 10.1096/fj.13-244046
- R. G. Tabak, C. D. Schwarz, D. L. Haire-Joshu. Associations between feeding practices and maternal and child weight among mothers who do and do not correctly identify their child’s weight status. Obesity Science & Practice, 2016; DOI: 10.1002/osp4.88
- k-state.edu/media/newsreleases/2017-02/kidsandveggies2617.html
- A systematic review of grandparents’ influence on grandchildren’s cancer risk factors Chambers SA, Rowa-Dewar N, Radley A, Dobbie F (2017) A systematic review of grandparents’ influence on grandchildren’s cancer risk factors. PLOS ONE 12(11): e0185420.
- news.umich.edu/parents-think-twice-before-you-pressure-your-picky-eater/
