According to US researchers, young children who are given repeated courses of antibiotics are at greater risk than those who use fewer drugs of becoming obese.
The JAMA Pediatrics report found children who had had four or more courses by the age of two were at a 10% higher risk of being obese.
However, scientists warn this does not show antibiotics cause obesity directly and recommend children continue using them.
Many more studies are needed to explain the reasons behind the link, they say.
Researchers from the University of Pennsylvania and Bloomberg School of Public Health reviewed the health records of more than 64,500 American children between 2001 and 2013.
The children were followed up until they reached five years of age.
Young children who are given repeated courses of antibiotics are at greater risk than those who use fewer drugs of becoming obese
Almost 70% of them had been prescribed two courses of antibiotics by the time they were 24 months old.
But those who had four or more courses in this time were at a 10% higher risk of being obese at the age of five than children who had been given fewer drugs.
And the type of antibiotics they were prescribed appeared to make a difference too – those given drugs targeted at a particular bug were less likely to put on weight.
But those given a broad-spectrum antibiotic – that can kill several types of bacteria indiscriminately – were more likely to have a higher body mass.
Prof. Charles Bailey at the University of Pennsylvania, said: “We think after antibiotics some of the normal bacteria in our gut that are more efficient at nudging our weight in the right direction may be killed off and bacteria that nudge the metabolism in the wrong direction may be more active.”
And researchers say the study highlights that over prescribing inappropriate antibiotics could have a negative impact on child growth.
Meanwhile in a separate study, scientists reporting in the journal of the American Society for Microbiology found that a species of gut bacteria – called Clostridium ramosum – could promote weight gain in mice.
Mice with these bacteria present in their guts became obese when fed a high-fat diet, while those that did not have the bacteria put on less weight despite being given high-calorie meals.
The scientists, from the German Institute of Human Nutrition, in Nuthetal, are now trying to understand how the bacteria interact with digestion.
According to a new research, Subway meals contain nearly as many calories and more salt than those from McDonald’s.
Subway chain may promote itself as the “healthy” fast food restaurant but the new study suggests that it is not much healthier than McDonald’s, and in terms of salt it is worse.
Researchers from the University of California Los Angeles (UCLA) found that teenagers who bought Subway meals in America consumed nearly as many calories as those who bought a meal from McDonald’s.
They believe that eating from both restaurants is likely to contribute towards overeating and obesity.
According to a new research, Subway meals contain nearly as many calories and more salt than those from McDonald’s
“Every day, millions of people eat at McDonald’s and Subway, the two largest fast food chains in the world,” said Dr. Lenard Lesser, who led the research.
“With childhood obesity at record levels, we need to know the health impact of kids’ choices at restaurants.”
The researchers asked 97 people aged between 12 and 21 to buy meals at McDonald’s and Subway restaurants in a shopping centre in California.
The participants went to each restaurant on different weekdays between 3 p.m. and 5 p.m., and paid for the meals with their own money.
The researchers used the participants’ receipts to record what each customer ate and estimated calorie counts from information on the chains’ websites.
The researchers found that the participants bought meals containing an average of 1,038 calories at McDonald’s and an average of 955 calories at Subway.
“We found that there was no statistically significant difference between the two restaurants, and that participants ate too many calories at both,” said Dr. Lenard Lesser.
The Institute of Medicine in the U.S. recommends that school lunches do not exceed 850 calories.
The researchers also found that the sandwiches bought by the participants from Subway in America averaged 784 calories, compared to 572 calories at McDonald’s in the U.S.
Sugary drinks from Subway contained an average of 61 calories while the McDonald’s alternatives contained an average of 151 calories.
The participants consumed 102 grams of carbohydrates at Subway compared to 128 grams at McDonald’s.
The meals contained an average of 36 grams of sugar at Subway and 54 grams at McDonald’s.
Salt intake averaged 2,149 mg at Subway and 1,829 mg at McDonald’s.
“The nutrient profile at Subway was slightly healthier, but the food still contained three times the amount of salt that the Institute of Medicine recommends,” Dr. Lenard Lesser said.
The authors suggested that the higher sodium content of the Subway meals likely came from the restaurant’s processed meat.
The researchers also accepted that there were some weaknesses in the study – they did not track the subjects’ meals for the rest of the day, so it was unclear whether participants ate less at other times of the day to compensate for the excess calories.
Dr. Lenard Lesser recommends that McDonald’s customers eliminate sugary drinks and French fries from their orders and suggests that at Subway people should opt for smaller subs and ask for less meat.
As part of Subway’s “Where Winners Eat” advertising campaign it worked with athletes including Olympic gymnast Louis Smith to promote its Eat Fresh range.
A Dutch study has found that severely obese children are putting their heart at danger even while they are still in primary school.
Heart disease is normally associated with middle age, but the early warning signs were detected in children between the ages of two and 12.
Two-thirds of the 307 children studied had a least one early symptom such as high blood pressure.
The findings were presented in Archives of Disease in Childhood.
Obesity is a growing problem around the world with more people becoming obese and at a younger age.
A Dutch study has found that severely obese children are putting their heart at danger even while they are still in primary school
Two-year-olds with a Body Mass Index (BMI), a measure of obesity, greater than 20.5 are classed as severely obese. By the age of 18, a BMI of 35 is a sign of severe obesity.
Researchers at the VU University Medical Centre in Amsterdam collected data from the Dutch Paediatric Surveillance Unit between 2005 and 2007.
They looked at warning signs of heart disease in the severely obese children.
“Remarkably, 62% of severely obese children under 12 years of age already had one or more cardiovascular risk factors,” the study concluded.
More than half had high blood pressure, and there were also cases of low “good cholesterol” and high blood sugar, which can result in Type 2 diabetes.
The researchers said this “may lead to cardiovascular disease in young adulthood”.
Children who watch TV an increased number of hours between the ages of two and four years old risk larger waistlines by age 10.
A Canadian study found that every extra weekly hour watched could add half a millimetre to their waist circumference and reduce muscle fitness.
The study, in a BioMed Central journal, tracked the TV habits of 1,314 children.
Experts say children should not watch more than two hours of TV a day.
Researchers found that the average amount of television watched by the children at the start of the study was 8.8 hours a week.
This increased on average by six hours over the next two years to reach 14.8 hours a week by the age of four-and-a-half.
Every extra weekly hour spent by children in front of a TV could add 0.5 mm to their waist circumference and reduce muscle fitness
Fifteen per cent of the children in the study were watching more than 18 hours per week by that age, according to their parents.
The study said the effect of 18 hours of television at 4.5 years of age would by the age of 10 result in an extra 7.6 mm of waist because of the child’s TV habit.
As well as measuring waist circumference, the researchers also carried out a standing long jump test to measure each child’s muscular fitness and athletic ability.
An extra weekly hour of TV can decrease the distance a child is able to jump from standing by 0.36 cm, the study said.
The researchers said that further research was needed to work out whether television watching is directly responsible for the health issues they observed.
Dr. Linda Pagani, study co-author from the University of Montreal, said it was a warning about the factors which could lead to childhood obesity.
“The bottom line is that watching too much television – beyond the recommended amounts – is not good,” Dr. Linda Pagani said.
The American Academy of Pediatrics recommends that children aged over two should not watch more than two hours of television per day.
Dr. Linda Pagani added: “Across the occidental world, there have been dramatic increases in unhealthy weight for both children and adults in recent decades.
“Our standard of living has also changed in favor of more easily prepared, calorie-dense foods and sedentary practices.
“Watching more television not only displaces other forms of educational and active leisurely pursuits but also places them at risk of learning inaccurate information about proper eating.”
The study said that habits and behaviors became entrenched during childhood and these habits might affect attitudes to sporting activities in adulthood.