The survey tracked the weight, height and lung function of 3,700 adults between 1992 and 2014. At the time they were recruited, participants were aged between 20 and 44 and were measured on three occasions over a period of two decades.
While it is expected that lung function will decline naturally over the course of the human lifespan, researchers at the Barcelona Institute of Global Health found that the rate at which this decline happens becomes much more rapid in individuals who experience moderate or high weight gain during mid-life.
Conversely the findings, which were published in the journal Thorax, showed that weight loss stopped this decline in its tracks and that people who maintained a healthy weight throughout adulthood exhibited a much less pronounced decline in respiratory health.
As a result, the authors have underlined the importance of leading a healthy lifestyle and body weight to protect respiration.
Dr Judith Garcia-Aymeric, corresponding author of the study, said: “Lung function is a significant predictor of future morbidity and mortality in the general population.
”Maintaining good lung function across adult life is important to prevent chronic respiratory diseases, which nowadays represent a serious public health problem around the world.
“There is consistent evidence showing overweight, obesity and weight gain in adulthood are detrimental to lung function.”
While there is plenty of evidence connecting poor lung strength in adulthood with being overweight, the authors stated that previous studies have been relatively short term and only followed participants up to the age of 50.
To gauge the potentially longer impact of changes in weight Dr Garcia Aymeric and her colleagues followed some participants over the course of 23 years and well in to their 60s.
During the study, the team found that around half (53 per cent) of the participants put on a moderate amount of weight – 0.55 to 2.2lbs a year (0.25 to 1 kg) – while one in eleven put on more than 2.2lbs annually.
In addition, less than one-in-twenty-five lost weight and a third (34 per cent) maintained.
At the outset around one in eight (12 per cent) participants were considered underweight, more than half (57 per cent) of normal weight and around one in four (24 per cent) overweight. Meanwhile, six per cent were categorised as obese.
Analysis of the results showed changes in weight over the 20 years were associated with the rate at which lung capacity declined.
Those who experienced moderate and high weight gain exhibited a rapid decline in lung capacity, while those who started out obese and lost weight showed a slower decline.
This was also the case for those who had been underweight at the start of the study, and those whose weight remained stable throughout.
The results stood after taking account of potentially influential factors including the participants history of smoking or passive smoking, how often they exercised and if they had asthma or any serious illness such as diabetes or cancer.
“Control of weight gain is important for maintaining good lung function in adult life,” Dr Garcia-Aymeric said.
“Our findings reinforce the public health message that being overweight and obesity have deleterious effects on health, including respiratory health.
”However, the negative effects of overweight and obesity on lung function can be reversed by weight loss even later in adult life.”
The researchers were keen to highlight that the findings drew on total body weight, which did not distinguish between muscle and fat, and that the team was not able to assess how long it took for a change in weight to affect the lungs.
While being overweight can lead to a variety of health issues, a recent study revealed that it is not just physical health that is at risk, especially for women.
In 2018, researchers from the Universidad Peruana de Ciencias Aplicadas found that participants with a larger waistline may also have a greater chance of suffering from anxiety.
The team assessed data collated from 5,580 women from 11 countries in Latin America, with their ages ranging from 40 to 59 years old.
The researchers found that 57.9 per cent of the women were postmenopausal, while 61.3 per cent had anxiety. They also used a measurement introduced by the North American Menopause Society (NAMS) which states that a woman should be classified as obese if the length of her waist is greater than half of her height.
The team concluded that participants in the middle and upper thirds of waist-to-height ratios had a more significant chance of having anxiety.