An increase of 10 million in 23 years in anything is quite a jump, a jump that becomes quite alarming if it’s true of a negative health trend.

When you picture the world’s population of children, you probably see many as emaciated inhabitants of poverty-stricken third-world countries. I know I do.

Or at least I did until I read a recent World Health Organization report.

It noted that despite the millions of starving children in third-world countries, somehow, someway, the number of obese children in the world from 1990 to 2013 increased by 23.8 percent.

From 32 million to 42 million. By 10 million in 23 years.

This causes concern because of the health problems childhood obesity creates, both short-term and long-term. Obese children tend to be sicker than healthy-weight children and also retain that weight as adults.

Obese adults develop type 2 diabetes, certain cancers, and heart disease at a far higher rate than healthy-weight adults. These diseases not only compromise the quality of life appreciably but also shorten it significantly.

As a result, parents should do everything and anything possible to help a child maintain a healthy weight.

A recent study helps explain why a healthy weight during childhood is such an aid to middle-age health. Research with rodents at the Liggins Institute University of Auckland in New Zealand lead the researchers there to hypothesize that doing so and exercising the proper amount helps the body better handle extra calories from high-fat foods later in life.

In the study published in the journal Frontiers in Physiology, researchers fed 40, 22-day-old male rats (an age that corresponds to human childhood) a normal rat diet and allowed them to move freely and use an exercise wheel whenever. Another 40 were fed a high-fat diet and some of those had their exercise controlled.

Only about a third had access to an exercise wheel during the entire experiment. Nearly the same number were given access to an exercise wheel at the 67-day mark, while the remainder on the high-fat diet were not allowed to exercise from the start.

Professors Mark Vickers, Elwyn Firth, Dr. Justin O’Sullivan, and Ph.D. student Dharani Sontam then extracted RNA samples from the rats in order to analyze the effect the diets and the exercise routines had on their genes. They found that the rats fed the high-fat diet but allowed to exercise actually had some of the genes responsible for inflammation “turned down.”

While some inflammation in humans is necessary and seen as helpful, unwarranted inflammation frequently brought on by outside influences, such as a poor diet, increases the odds of many health problems, including heart disease, diabetes, and certain cancers.

“The rats [eating the high-fat diet] still got fat,” explains Dr. O’Sullivan in an online article posted at the Medical News Today website, “but that early extra exercise basically set them up so that even though they put on weight they didn’t have the same profile of negative effects that [are] common with a high-fat diet.”

Such as inflammation.

And the inflammation genes remained “turned down” 60 days after the rats stopped exercising, the time equivalent to a human’s middle age.

Additionally, the researchers found that the exercise reduced bone mass loss and improved overall bone health in the rats. Good bone health in humans helps the body’s metabolic rate run higher, whereas poor bone health causes it to run lower, increasing the odds of weight gain and obesity.

Now it wasn’t that long ago that the medical world believed that being overweight during childhood was fine. My family doctor, for instance, told my mother that I would “grow out” of my baby fat, but that didn’t seem to be happening.

So during the winter I turned 12, I took matters into my own hands.

I joined a three-day-a-week wrestling club while still playing little league basketball, started walking home for lunch on schooldays, and limited myself to an 8-ounce serving of yogurt during those lunches.

My parents played little part in my weight dropping from 125 to 111 pounds, but their help really wasn’t required back then. It was far easier to lose weight as a child in the early 70s than it is today.

My family only ate at a sit-down or a fast-food restaurant once every two weeks usually — the Friday my dad got paid. It wasn’t until the summer I turned 12 that a 24-hour convenience store was within walking distance of my house.

Moreover, kids back then came home from school and gathered outside on fair-weather days and played and played and played and played.

Because so much about growing up has changed, parents now need to regulate a child’s dietary and exercise habits or be accused of neglect.