Weight loss can protect overweight boys from developing type 2 diabetes

July 12, 2018 by Lise Geisler Bjerregaard, Bispebjerg And Frederiksberg Hospital, ScienceNordic
Weight loss can protect overweight boys from developing type 2 diabetes
Preventing and treating overweight in prepubescent teenagers can reduce the risk of developing type 2 diabetes later in life. Credit: Shutterstock

A new study shows that overweight seven year olds have a higher risk of developing type 2 diabetes as adults, but only if they are still overweight by the time they hit puberty and beyond.

It's well known that in childhood leads to an increased risk of type 2 diabetes later in life. Our research has previously shown that children who weigh just a couple of kilograms too much have a much higher chance of developing the disease, and that this effect is more pronounced in girls than boys.

But in this study we didn't have information from adults, for which we received some criticism, for exclusively studying child and not adult body mass indices (BMIs). This meant that we couldn't judge whether weight loss before adulthood could help to reduce the risk of developing diabetes later in life.

Other studies were too small to shed any light on the matter. So, together with Associate Professor Jennifer L. Baker among other colleagues, I revisited the issue in a new study.

Largest study of its kind

We analysed data from 62,565 men recorded in school health records (at the age of seven and thirteen years) and conscription examination records (medical records of young Danish men called up for national service) between the ages of 17 to 26.

Men born between 1939 and 1959 were tracked via the National patient register. We identified 6,710 men (approximately 10 per cent), who went on to develop type 2 diabetes.

The study is the largest of its kind anywhere in the world and it is published in the New England Journal of Medicine.

Reduces the risk for type 2 diabetes

As reported in previous studies, we found an increased risk for type 2 diabetes in adulthood among boys who had overweight (here we use the term overweight to describe the disease, in the same way we use 'type 2 diabetes') at age seven, thirteen, and older.

In our study, we showed that losing weight before reaching early adulthood subsequently reduced the risk of developing type 2 diabetes later on. Specifically, boys with overweight had the same risk of developing type 2 diabetes later in life (between the ages of 30 and 60) as boys of a normal weight, provided they reduced their BMI before and maintained that weight loss until early adulthood.

Boys were only more likely to develop type 2 diabetes as adults if the overweight remained by the time they reached puberty and beyond.

We also saw that severely overweight seven and thirteen year old boys benefit from reducing their BMI before they reach puberty. They cannot completely eliminate the risk, but they can reduce it significantly.

Overweight thirteen-year-olds at higher risk

You can see example BMIs for each age group in the table below.

Weight loss can protect overweight boys from developing type 2 diabetes
These figures are minimum values. I.e. A BMI between 17,4 and 19,0 kg/m2 for a 7-year-old-boy would be considered overweight. But a BMI of 19,1 kg/m2 and above is classed as severely overweight. Credit: International Obesity Task Force

Let's take two examples as an illustration:

  • A boy aged seven weighs 23 kilograms and measures 1.22 metres tall. If we divide his weight by his height (23/1.22) we can calculate his BMI: 15.4 kilograms per square metre. He has a normal weight.
  • A boy aged seven, weighs 28 kilograms and is 1.22 metres tall. He has a BMI of 18.8 kilograms per square metre. He is overweight.

Men who were overweight in all age groups (seven, thirteen, and early adulthood) were four times more likely to develop type 2 diabetes between the age of 30 and 60, and this risk was the same for men who were of a normal weight at seven but had become overweight by the age of thirteen and after, compared with men who were at all ages.

For men who had only put on weight by the time they hit , the risk was three times higher.

Even small changes in BMI count

Reducing BMI between the age of seven and eighteen was associated with a reduced risk of developing type 2 diabetes.

Even boys with obesity could halve their risk by reducing their BMI from 'obesity' to 'overweight,' and they could remove the elevated risk entirely by bringing their BMI down to a normal level.

In contrast, every single increase in BMI was associated with an increased risk of type 2 diabetes.

In general, there was an increased risk of type 2 diabetes among less educated eighteen-year-olds. But this could not explain the increased risk observed in men with overweight. And regardless of educational level, they could all reduce their risk of developing type 2 diabetes by losing weight before puberty.

We need to prioritise prevention of overweight in children

All in all, our results show that overweight around the age of puberty indicates a pattern of weight gain, which is particularly significant for the risk of developing type 2 diabetes.

Today, as many as 20 per cent of children are overweight. Our results suggest that preventing and treating overweight in prepubescent teenagers can help to reduce their risk of developing type 2 diabetes later on.

These are encouraging results.

Research among girls is now needed

The next stage is to study whether women experience the same beneficial results by reducing their BMI before puberty, and whether the benefits also apply to other weight-related conditions such as heart disease and stroke.

And we also need to find out whether losing weight in adulthood carries the same benefits.

Other studies show that loss in adulthood delays the development of type 2 . Therefore, we expect that at any time from childhood to has the same beneficial effect.

Explore further: Getting kids to a good weight by 13 may help avoid diabetes

More information: Lise G. Bjerregaard et al. Change in Overweight from Childhood to Early Adulthood and Risk of Type 2 Diabetes, New England Journal of Medicine (2018). DOI: 10.1056/NEJMoa1713231 A. Llewellyn et al. Childhood obesity as a predictor of morbidity in adulthood: a systematic review and meta-analysis, Obesity Reviews (2015). DOI: 10.1111/obr.12316

Related Stories

Getting kids to a good weight by 13 may help avoid diabetes

April 4, 2018
There may be a critical window for overweight kids to get to a healthy level. Those who shed their extra pounds by age 13 had the same risk of developing diabetes in adulthood as others who had never weighed too much, a large ...

Overweight boys at greater risk of colon cancer as adults, but losing weight may modify risk

May 20, 2017
New research presented at this year's European Congress on Obesity (ECO) in Porto, Portugal (17-20 May) suggests that overweight boys may be at greater risk of colon (bowel) cancer when they grow up than their slimmer friends. ...

Change in BMI during puberty tied to later heart failure risk

March 30, 2018
(HealthDay)—Change in body mass index (BMI) to overweight during puberty significantly increases men's risk of heart failure later in life, according to a study published online March 12 in the Journal of Internal Medicine.

Being overweight linked to longer life in older diabetics

June 9, 2017
Among older patients with diabetes, those who are overweight or obese may have a lower risk of dying prematurely than their normal weight counterparts. The finding comes from a recent analysis of published studies.

Maintaining the same weight as you age may prevent diabetes – even if you're overweight to begin with

May 17, 2017
It is well known that losing weight reduces your risk of developing type 2 diabetes. Our latest research shows that maintaining the same weight as you age may also prevent diabetes, even in people who are moderately overweight.

Excessive BMI increase during puberty identified as a new risk factor for mortality due to cardiovascular disease

November 9, 2016
Boys with a large increase in body mass index (BMI) during puberty are at increased risk of death due to cardiovascular disease later in life. There is no corresponding risk among boys overweight when younger and who have ...

Recommended for you

Genomic study brings us closer to precision medicine for type 2 diabetes

September 21, 2018
Most patients diagnosed with type 2 diabetes are treated with a "one-size-fits-all" protocol that is not tailored to each person's physiology and may leave many cases inadequately managed. A new study by scientists at the ...

High gluten diet in pregnancy linked to increased risk of diabetes in children

September 19, 2018
A high gluten intake by mothers during pregnancy is associated with an increased risk of their child developing type 1 diabetes, suggests a study published by The BMJ today.

Anti-inflammatory protein promotes healthy gut bacteria to curb obesity

September 19, 2018
Scientists from the UNC School of Medicine discovered that the anti-inflammatory protein NLRP12 normally helps protect mice against obesity and insulin resistance when they are fed a high-fat diet. The researchers also reported ...

Study reveals the current rates of diagnosed type 1 and type 2 diabetes in American adults

September 18, 2018
A new study from the University of Iowa finds that type 2 diabetes remains overwhelmingly the most common type of diabetes diagnosed in American adults who have the disease.

Research reveals link between immunity, diabetes

September 14, 2018
When it comes to diet-induced obesity, your immune system is not always your friend.

BPA exposure in U.S.-approved levels may alter insulin response in non-diabetic adults

September 14, 2018
In a first study of its kind study, researchers have found that a common chemical consumers are exposed to several times a day may be altering insulin release. Results of the study, led by scientists at the University of ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.