According to a study conducted by Université de Montréal’s School of Public Health researchers, overweight or obese adults are found to breathe up to 50% more air per day, compared to people at a healthy weight. This additional intake makes overweight or obese individuals more vulnerable to air contaminants, such as ammonia, sulphur dioxide, ozone, and nitrogen dioxide that lead to asthma and other pulmonary diseases.
The findings, which were published in the international journal Risk Analysis, reveal that Obese Class 2 people – those individuals whose weight is between 35 and 40 kilos for each square metre of their body – have the highest average air inhalation, or 24.6 m3 per day. “That’s 8.2 m3 more than the 16.4 m3 an average adult with normal weight breathes daily, or 50% more air and pollutants,” explained professor Pierre Brochu.
The study also found that for overweight or obese children, daily inhalation rates are 10-24% higher than for normal weight children.
Brochu’s study is based on an analysis of data from 1,069 participants aged 5 to 96 years, compared with data collected from 902 normal weight people (in a study conducted by Dr. Brochu in 2011). Data were analyzed, among other things, according to participant age and gender. Adults were also classified according to their body mass index, determined as follows:
- Normal weight: 18.5-<25 kg/m2
- Overweight: 25-<30kg/m2
- Obese class 1: 30-<35 kg/m2
- Obese class 2: 35-<40 kg/m2
- Obese class 3: 40 kg/m2 or more.
Inhalation rates were determined using disappearance rates of ingested tracers (deuterium and heavy oxygen) measured in urine samples of free-living people for an aggregate period of more than 16,000 days. The tracers were used to measure the quantity of carbon dioxide exhaled by each participant during real-life situations in their normal surroundings each minute of the day, 24-hours per day, over 7 to 21 days.
Looking distinctly at the results for obese children, Brochu and his team have found the situation to be more worrisome. According to data, because children have a much higher metabolism – in relation to their low body weight – they breathe more air per kilogram of weight than obese adults do to maintain their basic functions and perform their daily activities.
The study finds that the same trend applies to men compared to women. “It remains to be seen if high inhalation rates are a factor in the development of asthma and other lung diseases in adults and children,” Brochu added.