It confirms that the nation’s obesity epidemic is being passed down through the generations – with females most at risk of inheriting unhealthy weight.
The findings have emerged after a 20-year study of almost 1,500 families in the west of Scotland in which researchers looked at whether obesity in parents was passed on to their children.
It revealed that 9 per cent of children of normal-weight parents were obese, compared with 24 per cent of children whose parents were overweight or obese themselves.
Among women, 17 per cent of mothers were obese, but that figure rose to 20 per cent among daughters, a far higher proportion than among fathers and sons or mothers and sons.
Although genetic factors also have a role to play in obesity, the gender differences were likely to be due to how children were fed, the researchers claim. Women were more likely to have a similar weight to their mother, and experts believe this could be due to mothers passing on their cooking skills and food choices to their daughters but not their sons.
Yesterday, health campaigners warned that the research was further confirmation of the health risks being stored up by the nation and said it showed that it is vital for experts to step in to help children who are showing signs of being overweight at a young age.
More than a quarter of Scots adults are now obese and the problem costs the health service £450 million a year in treating health-related problems such as diabetes, cancer and heart disease.
The research was carried out by scientists at Glasgow University and involved monitoring 1,500 families from the Paisley and Renfrew areas over a 20-year period.
The first generation had their details recorded, and their children’s details were taken when they had grown into adults.
Dr Jennifer Logue, a clinical lecturer in biochemistry and metabolic medicine at Glasgow University, found that while there was little change in the average body mass index (BMI) – the accepted measure of weight – among the families, those at the higher end of the scale became significantly bigger.
She said: “It’s not the entire population that have got bigger over the last 20 years, but those who were overweight seem to have got even bigger. Within these families, of the people whose parents were big, the children are now even bigger.”
There was a stronger relationship between daughters and their mothers’ weight than among other groups of relatives. “For everyone, if your parents are big, you’re going to be big, and the bigger families are having bigger children. But daughters seem to inherit more from their mother.”
The scientists do not think this is due to purely genetic factors – which would affect both boys and girls equally – or life events such as having children, which can make women gain extra weight, but could be a combination of genes and food choices.
Logue added: “We are not 100 per cent sure, but your mother does tend to be the main caregiver and decides what you are going to eat. You would think that would affect sons a bit more, but maybe when they are adults they are affected by what their partner is putting in front of them.
“Our theory is that it’s what mums are picking to feed their children. It may be that the genes related to obesity make you pick higher-fat foods and if you don’t have the best control over your own appetite, and pick higher-fat foods, that’s what a mum picks for her children.
“Therefore, that’s what the children are then going to do, whether they have inherited her genetics or they have inherited her habits.”
The research was published in this month’s European Journal Of Epidemiology.
Anti-obesity campaigners said the findings were further confirmation of the link between parents’ body type and their children’s.
Tam Fry, spokesman for the National Obesity Forum, said: “There’s a saying that if you want to know what your girlfriend’s going to look like in middle age, look at her mother.
“We now know from a very early age the likelihood of a child becoming fat, so we should keep a careful eye on it and teach the child about good lifestyle and exercise. The problem is we haven’t been doing that in the past and we now have a lot of people who would not be so overweight if they had been properly monitored as children.”
A Scottish Government spokesman said it was taking a multi-pronged approach to tackling obesity among young people through government, local authorities, schools, the NHS and parents.
“Our action plan on obesity prevention sets out actions being taken to change our environment to make it easier for everyone to make healthy choices, including eating better and becoming more active, and we will be spending more than £7.5 million in the next three years on projects to encourage healthy eating.
“We are also investing £2m in targeting specific groups of people who are furthest away from meeting recommended physical activity guidelines.”