They steal your toys, call you names and irritate you endlessly growing up.
But having a sibling might actually have a positive effect on your health, a study has suggested.
Researchers found only-children were far more likely to be obese by the time they turned seven.
By contrast, it was seven times less common for youngsters who had a brother or sister to be severely overweight.
This is because families with multiple children eat out less and are forced to plan meals in advance to feed more mouths, scientists believe.
Youngsters who have a brother or sister are up to seven times less likely to be severely overweight by the age of seven, research suggests (file)
One in five British children are overweight when they start primary school, with that figure rising to one in three when they start secondary school.
In the US, almost a third of children and teenagers are either overweight or obese, with one in five obese.
The Royal College of Paediatrics and Child Health estimates half of all children will be overweight or obese by 2020.
Obesity can trigger a slew of potentially-fatal health conditions later in life, including heart disease and strokes, high blood pressure, type 2 diabetes and cancer.
In the new study, researchers from the University of Oklahoma looked at the eating habits of 68 youngsters over one week.
Twenty-seven only-children were split into one group, with the remaining 41 with siblings in another.
Among only-children, 37 per cent were obese compared to five per cent in the group with siblings.
There was also a stark BMI difference between the two groups. Only-children had a BMI percentile of roughly 72, compared to 53 in the sibling group.
The scientists, led by Chelsea Kracht, a professor in paediatric obesity and health behaviour, also measured the eating habits of the youngsters and their families.
Data was self-reported in daily food logs kept by their mothers over the course of the week.
WHAT IS OBESITY? AND WHAT ARE ITS HEALTH RISKS?
Obesity is defined as and adult having a BMI of 30 or over.
A healthy person’s BMI – calculated by dividing weight in kg by height in metres, and the answer by the height again – is between 18.5 and 24.9.
Among children, obesity is defined as being in the 95th percentile.
Percentiles compare youngsters to others their same age.
For example, if a three-month-old is in the 40th percentile for weight, that means that 40 per cent of three-month-olds weigh the same or less than that baby.
Around 58 per cent of women and 68 per cent of men in the UK are overweight or obese.
Obesity can spur on conditions including type 2 diabetes, which can cause kidney disease, blindness and even limb amputations.
Carrying dangerous amounts of weight has also been linked to 12 different cancers.
This includes breast, which affects one in eight women at some point in their lives.
Among children, research suggests that 70 per cent of obese youngsters have high blood pressure or raised cholesterol, which puts them at risk of heart disease.
Obese children are also significantly more likely to become obese adults.
And if children are overweight, their obesity in adulthood is often more severe.
Teachers filled in meal diaries for children while they ate at school which noted food type and portion size.
Mothers also completed a questionnaire which looked at typical family eating habits, nutritional intake and physical activity levels.
This included meal and drink choices, as well as whether they ate at a table or in front of the TV.
Every question had four response options – almost never, sometimes, usually and almost always.
The healthier practice received the highest scoring of four points per question, with a maximum score of 80 points overall.
Only-children reported lower scores on family eating practices, drink choices, nutritional intake and physical activity.
As for maternal weight, a higher amount of singleton mothers were overweight or obese compared with mothers with multiple children.
More singleton mothers were also employed full-time, which has been associated with child weight gain before the age of five years.
Researchers say the findings point to unhealthy habits of parents being transferred to their children.
Dr Kracht said: ‘Nutrition professionals must consider the influence of family and siblings to provide appropriate and tailored nutrition education for families of young children.
‘Healthier eating behaviors and patterns may result from household-level changes rather than peer exposure, as peer exposure is also present in away-from-home care.
‘Efforts to help all children and families establish healthy eating habits and practices must be encouraged.’
These ﬁndings go against a popular theory that only-children should have lower obesity rates because they have less competition for parental care and higher household income.
A University of Buffalo study today revealed babies whose mothers are warm and affectionate with them are less at-risk of obesity in their first months of life.
Babies whose mothers are ‘warm and sensitive’ while playing with their infants are less likely to gain excess weight, study finds
Babies whose mothers are warm and affectionate with them are less at-risk of obesity in their first months of life, a new study finds.
Risk factors for obesity are many, various and come into play before we are even born.
The silver lining to their diffuse nature is that it suggests there are also many ways that obesity risks can be reduced.
Among those risk factors are stress and poverty, so researchers at the University of Buffalo examined whether a mother’s behavior could offset her infant’s obesity risks.
When mothers spoke positively and in warm tones to their babies while while playing, those infants weight-gain patterns indicated they’d be less prone to obesity.
On the contrary, babies whose mothers spoke in harsh tones and behaved with low levels of hostility toward showed signs that they would gain unhealthy weight, the study found.
‘The prenatal period is a sensitive period of health and disease development,’ said lead study author Dr Kai Ling Kong.
‘Insults that happen in the womb have lifelong consequences.
‘But despite perturbations in fetal development, our study shows that it is possible to mitigate the effect of these exposures during early childhood by warmth, responsive and sensitive parenting in one’s home environment, especially in active play.’
About 18.5 percent of children in the US are obese, and about 80 percent of obese or overweight children will grow up to be obese adults.
A mother who is overweight or obese during her pregnancy is more likely to have a child who becomes obese, but so can less obvious risk factors, such as smoking during pregnancy (which is also linked to low birth weight) and stress.
In fact, a mother’s low socioeconomic is a strong predictor that her child will grow up to be obese.
But offsetting that risk factor is particularly difficult. For example, better diets in childhood could, in theory, help, but the foods that comprise a healthy diet – whole fruits and vegetables – are more expensive than highly-processed foods that drive obesity.
The University of Buffalo researchers wondered if simpler behavioral differences in parents could have protective effects for infants, even if the family lived in financial stress.
WHAT SHOULD A BALANCED DIET LOOK LIKE?
Meals should be based on potatoes, bread, rice, pasta or other starchy carbohydrates, ideally wholegrain, according to the NHS
• Eat at least 5 portions of a variety of fruit and vegetables every day. All fresh, frozen, dried and canned fruit and vegetables count
• Base meals on potatoes, bread, rice, pasta or other starchy carbohydrates, ideally wholegrain
• 30 grams of fibre a day: This is the same as eating all of the following: 5 portions of fruit and vegetables, 2 whole-wheat cereal biscuits, 2 thick slices of wholemeal bread and large baked potato with the skin on
• Have some dairy or dairy alternatives (such as soya drinks) choosing lower fat and lower sugar options
• Eat some beans, pulses, fish, eggs, meat and other proteins (including 2 portions of fish every week, one of which should be oily)
• Choose unsaturated oils and spreads and consuming in small amounts
• Drink 6-8 cups/glasses of water a day
• Adults should have less than 6g of salt and 20g of saturated fat for women or 30g for men a day
Source: NHS Eatwell Guide