Genetic Obesity

It is no secret that obesity rates are on the rise. Not only are adults working on expanding waistlines, but their children are as well. Oftentimes we see obese children, huffing and puffing, trailing behind their overweight parents. The common sentiment generally leads us towards, "Kids these days, spending too much time indoors and not enough time playing outside."

Fortunately, this blog is not about the argument for or against the activity level of children, nor is it going to get into the specifics of what children are eating these days. Instead, I am going to defend the children and point the blame at the parents. Despite the fact that it has become all too easy to just call them lazy kids, obese children may in fact be starting off behind the 8-ball because of their parents.

I have picked on the dads a bit in the past with my blog written about genetic inheritance of obesity from unfit dads. There have been other studies that have also pointed out the importance of the health and fitness level of fathers when trying to conceive.

One could guess that the health status of the mother is also important when trying to conceive. More and more research is now supporting this hypothesis, such as a recent review released in The Lancet:

Influence of maternal obesity on the long-term health of offspring

In addition to immediate implications for pregnancy complications, increasing evidence implicates maternal obesity as a major determinant of offspring health during childhood and later adult life. Observational studies provide evidence for effects of maternal obesity on her offspring's risks of obesity, coronary heart disease, stroke, type 2 diabetes, and asthma. Maternal obesity could also lead to poorer cognitive performance and increased risk of neurodevelopmental disorders, including cerebral palsy. Preliminary evidence suggests potential implications for immune and infectious-disease-related outcomes. Insights from experimental studies support causal effects of maternal obesity on offspring outcomes, which are mediated at least partly through changes in epigenetic processes, such as alterations in DNA methylation, and perhaps through alterations in the gut microbiome. Although the offspring of obese women who lose weight before pregnancy have a reduced risk of obesity, few controlled intervention studies have been done in which maternal obesity is reversed and the consequences for offspring have been examined. Because the long-term effects of maternal obesity could have profound public health implications, there is an urgent need for studies on causality, underlying mechanisms, and effective interventions to reverse the epidemic of obesity in women of childbearing age and to mitigate consequences for offspring.

So just as your parents pass along traits such as hair colour, eye colour, height, personality, etc., you pick up a few of their lifestyle habits as well. How can this be? Everyone starts life with a clean slate, right? Well, no, as it turns out.

Research is telling us that the lifestyle choices made by our parents cause what's called DNA methylations that can actually be passed on through reproduction. DNA methylation is like using a light switch in a room in your house. Obviously, when you want a light on, you hit the light switch. How this works on your DNA, is that when a specific signal needs to be saved for further DNA replication, our bodies "install" light switches or signals on parts of our genes essentially turning them on or off. Favourable lifestyle choices turn on favourable genes. Unfortunately, unfavourable lifestyle choices can also turn off favourable genes. These genes that have been turned off can also be passed on to your children.

This is both comforting/encouraging to some of you, but also a very scary premise for others. It should be encouraging to know that if you are individual who struggles with keeping a healthy weight, it is not necessarily the effort you put forth, or having a bad plan in place, but simply because you are genetically more prone to be overweight. That is not something that should make you quit, just realize that some have it easier than others when it comes to weight management.

This is also a terrifying premise considering the rise in obesity. If obese parents are passing on their less-than-favourable genetic information to their children, this is going to turn into one vicious cycle as each generation will have to fight harder and harder to reverse the effects of obesity. If you don't think this is a scary phenomenon, consider not only the reduced quality of life an overweight or obese person must face, not to mention the financial burden this places on our healthcare system.

If you are trying to conceive, or will be in the future, consider improving your overall health by eating sensibly and exercising regularly to hopefully prevent a future like that seen in Wall-E (video below).

More reading on this:

1. Babies born to mothers who are obese or have gestational diabetes are larger and have more body fat.

2. Babies born to mothers who are obese or have gestational diabetes have fatty liver.

3. Babies born to mothers who are obese or have gestational diabetes are insulin resistant from birth.

4. Babies born to mothers after the mother lost weight have a reduced risk of obesity versus children born to mothers that are still overweight.

Tyler Robbins B.Sc. CSCS
Director of Fitness
Head of CrossFit