The obesity epidemic is never far from the news desk, and for good reason. Today, around 1 in 3 American kids and teens are overweight, which is three times the rate it was in 1963.

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Researchers found significant heart defects in MRI scans of obese children.

This relatively new plague of juvenile obesity is, of course, a huge concern.

Science has already uncovered a barrage of negative health implications tied to obesity. Even more worrying, perhaps, are the things we are yet to find out about obesity.

This range of unknowns is particularly obvious in children, because, since the birth of humanity, children have not been witnessed at such large sizes and in such high numbers.

Children who are overweight already display similar reactions to excess weight as adults. Issues such as high blood pressure, type 2 diabetes and elevated blood cholesterol levels, once the reserve of adults, are now known to strike at any age.

Added to the worrying barrage of physical woes, overweight kids and teens face additional psychological issues such as depression and low self-esteem - both epidemics in their own right.

New research presented at the American Heart Association's Scientific Sessions 2015 by lead study author Linyuan Jing, PhD, adds another worrying finding to the tsunami of weight-related health news.

Jing and colleagues took MRI scans of 20 overweight children and compared the function and dimensions of their hearts with 20 children within the normal weight range. The results make somber reading.

MRI scans produce sobering results

The overweight children did display negative health impacts due to their size and weight, such as asthma and depression, but none directly attributed to heart malfunction.

The scans, however, told a different story:

The team found that the obese youths had 27% more muscle mass in the left ventricle of their hearts and 12% thicker heart muscles, which are both signs of heart disease.

The study also considered 40% of the children to be "high-risk" because the type of thickening seen in their heart wall is associated with a reduced ability to pump blood.

Of the 20 obese children, seven were teenagers, but the younger participants yielded the most shocking results. The researchers were particularly surprised to see signs of heart disease in children as young as 8 years old: "This was alarming to us."

Jing hopes this study might spur parents on to spend a little more time and thought on their child's diet:

"Ultimately we hope that the effects we see in the hearts of these children are reversible; however, it is possible that there could be permanent damage. This should be further motivation for parents to help children lead a healthy lifestyle."

Childhood obesity

As mentioned above, 1 in 3 children in America are overweight. Even worse, perhaps, is that 70-80% of those children are likely to remain overweight for their entire lives.

In adulthood, 7 out of 10 Americans are overweight or obese. In other words, they outnumber people who are in a healthy weight range.

Surgeon General Richard Carmona spoke of the epidemic in chilling terms:

"Because of the increasing rates of obesity, unhealthy eating habits and physical inactivity, we may see the first generation that will be less healthy and have a shorter life expectancy than their parents."

The effects of childhood obesity can be complex, but in most cases, the causes are much less so. The bottom line is that children are taking on more calories than they are burning off.

Underlying this simple equation are a multitude of personal and societal causes. Factors include increased portion sizes, hours spent staring at screens rather than playing outdoors, eating the wrong kinds of foods and eating out more regularly.

A second sting in the tail

Jing and his team chose their candidates by measuring the children's height and weight. If they were in the 95th percentile - heavier than 95% of other children at that age and sex - they could be included.

During the process of selecting candidates, however, children with existing diabetes or who were too large to fit in the MRI scanner were rejected. Worryingly, if these children had been included, the overall picture might have been substantially worse.

Medical News Today recently covered news of the discovery of an obesity gene.