Health experts say a new study on obesity sheds more light on the link between weight gain and the risk of serious disease and death.
The massive research project – which involved nearly three million sets of data – suggests that even being slightly overweight doubles the chances of developing Type 2 diabetes.
The results have been presented to the 26th European Congress on Obesity taking place from April 28 – May 1 in Glasgow.
Researchers say the size of the study makes it different from anything that has previously been done.
It analysed data from the UK on more than 2.8 million adults, with an average age of 51, over an 18-year period between January 2000 and July 2018.
It divided subjects into five groups according to their Body Mass Index (BMI), which measures factors such as height, weight and activity level to estimate whether someone is healthy. These ranged from a reference group of those considered healthy, with a BMI between 18.5-25kg/m2, to those at the top end of the scale with severe obesity and a BMI of 40-45kg/m2 - Obesity class III.
The results were adjusted to take account of age, gender, and whether or not people smoked.
Risk of Type 2 diabetes
The study amounts to a warning for people who are only moderately overweight. For instance, people in the second category, with a BMI of 25-30, more than doubled the risk of developing Type 2 diabetes and sleep apnoea.
Further up the scale the risk increased even more. People with severe obesity – a BMI of 40-45 – were 12 times more at risk of Type 2 diabetes and 22 times more likely to develop sleep apnoea.
“The health risks linked with having excess body weight are particularly high for type 2 diabetes and sleep apnoea,” said report author Christiane Haase.
Those in that top category of Obesity class III also tripled the risk of heart failure, high blood pressure or high cholesterol levels – and had a 50 percent higher risk of dying prematurely than people with normal weight.
Type 2 diabetes causes high blood sugar levels, and 90 percent of people with the condition are said to have this type, according to Diabetes UK.
Although it is manageable it can lead to serious health problems, which in the UK has led to warnings of huge complications for the health service over the next 20 years.
Obesity 'trebles' worldwide in 30 years
“With the number of people living with obesity almost tripling worldwide over the past 30 years (105 million people in 1975 to 650 million in 2016), our findings have serious implications for public health,” Haase said.
The study was funded by the Danish pharmaceutical multinational, Novo Nordisk.
Its authors acknowledge the survey has limitations. For example, there are no firm conclusions about the cause of health problems; rather it focuses on observing the link with weight gain.
They also point out that the risk of health problems is dependent on whether people had issues at the start of the study. This is thought likely in many cases, as the survey was based on information from the UK Clinical Practice Research Datalink which collects anonymous patient data.