Weight gain: the mother-daughter link
Weight gain tends to run in families, and it's common for big bones or a slow metabolism to get the blame. But is it really all in the genes? Are you destined to inherit your mum's figure?
Here at Amanda Hamilton, we've been exploring the relationship between parent's and children's weight, looking at the science behind why we gain weight. Here are a few of the facts:
What is obesity?
The medical definition of obesity is having a body mass index (BMI) of 30 or more. Britain has one of the highest obesity levels in the world – 25% of adults have a BMI above 30, and this is predicted to reach 40% by 2030.
But BMI alone doesn’t tell us whether our health is at risk because of our weight. Plenty of athletes are classed as obese, yet are fit and healthy. What may be more alarming, from a health point of view, is the increasing size of our waistlines. The apple shape is becoming the norm, and a recent sizing survey suggests that the average waist in the U.K. is 16.5cm bigger than it was in the 1950s!
What causes weight gain?
If eating less and moving more is the magic formula for weight loss (and we all know it’s not as simple as that), the reason for weight gain is the opposite. We gain weight when we burn off fewer calories than we eat. A cumulative difference of just 1% between calories consumed and calories burnt can lead to a gain of 10kg in a decade.
Are you turning into your mother?
Several recent studies have explored the relationship between the weight of parents and the weight of their children. Simply put, the tendency to gain weight does run in families, and the link between mothers and daughters seems especially strong.
What are the similarities between your shape and your mum’s? Do you have similar habits? And are their things that you’ve tried to change about your body, without success? This is where things get complicated – how much does it depend on genes, and how much is about the lifestyle you learnt from your parents?
Our ancestors evolved to be able to survive periods of food shortage – those who were able to store more fat in times of plenty were more likely to survive during seasonal food shortages. So people with a genetic predisposition to store extra fat were better able to survive, reproduce and pass on these ‘thrifty genes’ to their offspring.
This doesn’t mean that gaining weight is fate. Genetics tend to affect appetite hormones and subconscious activity habits, which can also be consciously controlled.
In the womb
What a pregnant mother eats affects the metabolic environment of the developing baby. Although it is possible that exposure to too much sugar or fats while in the womb may alter factors related to appetite, the research on the impact of nutrition during pregnancy on children’s later weight is not yet clear.
Studies suggest that, when women gain more weight than is recommended during pregnancy, their children are more likely to become obese as adolescents. So that means there’s definitely no need to eat for two!
Families tend to share similar habits – eating the same foods, sharing hobbies, using the same mode of transport, TV viewing, and so on. Studies on twins show that the family environment doesn’t influence weight as strongly as genetics do, but it does account for about 25% of the difference in girls’ weight.
Meanwhile, researchers at the US National Institute of Child Health and Human Development found strong similarities between mothers and children where eating in the absence of hunger and binge eating were concerned. This highlights how closely a mother’s eating habits are copied by her children, and how important it is to model good habits.
What about body shape?
Your inner body type, especially the pear or apple shape, has a genetic influence too. So far, 14 areas of DNA have been linked to waist-hip ratio, each making a small difference. One gene, called FTO, influences the risk of weight gain around the middle. But the good news is that this can be counteracted by regular exercise. Unfortunately, it’s not as simple to alter the width of your hips!
So, what can I do?
While there are strong genetic links, you’re not destined to turn into your mother. The science is constantly moving on, and perhaps one day we’ll get individual lifestyle prescriptions based on our genes. But for now, it’s important to acknowledge that lifestyles in the U.K. are not as good as they could be! Health surveys show that 20% of us rarely walk for 20 minutes or more, and only a quarter of us eat our ‘five-a-day’. Small changes to diet and activity habits truly can make a big difference.
We can’t change our genes, but we can work with what our mothers gave us!