A study published in the Journal of Population Studies in March 2023 estimated that one in six deaths in the US is linked to excess weight or obesity. The researchers concluded that, "Existing studies have likely underestimated the mortality consequences of living in a country where cheap, unhealthy food has grown increasingly accessible, and sedentary lifestyles have become the norm"[1]. I would argue that Australia has similar norms.

Our nation has one of the highest rates of obesity in the world, in 2017-19 Australia was ranked fifth among OECD countries with one third of Australian adults living with obesity[2].

According to the ABS National Health Survey, 67% of Australian adults were overweight or obese (12.5 million people) in 2017-18, an increase from 63.4% in 2014-15. This study also found that 50% of 18-24 year olds were overweight or obese. The report’s authors extrapolated that if the current trend continues, more than 18 million Australians will be overweight or obese by 2030. The financial and other costs of obesity are significant, estimated to be around $11.8 billion in 2018 and will likely continue to rise, with the cost being around $87.7 billion in 10 years [3].

Many Australians consume more energy than they need through unhealthy diets that are high in sugar, saturated and/or trans fats, and alcohol. These diets are high in discretionary foods such as processed meats, savoury pastries, fried foods, confectionery, cakes, biscuits, and soft drinks. The Australian Dietary Guidelines state that healthy diets are based on whole foods, such as vegetables, fruit, wholegrain cereals, nuts, seeds, dairy products and alternatives, lean meat, chicken, fish, eggs, tofu, and legumes[2].

Obesity and low levels of physical activity are major risk factors for chronic health conditions. These people have a greater risk of developing cardiovascular disease, type 2 diabetes, osteoporosis, and dementia[2].

Obesity in overseas militaries

The prevalence of overweight and obese soldiers is a major issue that affects militaries across the world. According to numerous international studies, despite stringent bodyfat standards and physical fitness requirements, many nations are encountering higher levels of overweight and obese soldiers in their armed forces. This issue impacts the ability of militaries to attract and train new soldiers and affects operational effectiveness.

It is unlikely that young men and women who are obese will make it through the ADF recruitment process. This reduces the cohort of potential members and may lead to shortfalls in desired recruitment numbers, at a time when we need more people to enlist.

The US identified this as an emerging issue more than a decade ago. In 2012, Lieutenant General Mark Hertling, then Commanding General of US Army Europe, identified obesity as an impending threat to the US, and stated that it will affect their nation’s youth, economy, and future[4]. More recently he added, “The military has experienced increasing difficulty in recruiting soldiers as a result of physical inactivity, obesity, and malnutrition among the nation’s youth. Not addressing these issues now will impact our future national security.”[5].

In 2018 Major General Allen Batschelet, then in charge of the US Army Recruiting Command, stated that the biggest single reason for failing to meet the US enlistment requirements at that time was obesity. He also stated that this was becoming a national security issue, and said, “The obesity issue is the most troubling because the trend is going in the wrong direction,” and that, “It’s a sad testament to who we are as a society right now”[6].

Being ‘Not fit to serve’ is a major issue for the US military. Individuals in the 17-24 age range account for 90% of US military applicants; however, in 2018 71% of young people in the US were not fit to join the military if they wanted to, with the five main reasons being overweight, obesity, having a low education, using drugs, and having a criminal record[5].

In a US study published in 2015, the combined overweight and obesity levels in active-duty personnel rose to more than 60% between 1995 and 2008. The authors stated that the high prevalence of military personnel being overweight and obese needs urgent attention and has implications for Department of Defense efforts to improve the health, fitness, readiness, as well as quality of life for active-duty forces[7].

In a more recent US study published by Military Medicine in 2022, it was found that there are more active-duty service members with an overweight body mass index (BMI; 25–29.9 kg/m2) than any other BMI category (at 51.6%), with another 15.1% classified as obese. Only 33.3% were classified as in the normal weight range[8].

Obese soldiers also appear to have more injuries. Between 2008 and 2017, active-duty soldiers in the US had more than 3.6 million musculoskeletal injuries. Active-duty soldiers with obesity were 33% more likely to suffer musculoskeletal type injuries[5].

In 2013 the British Army conducted an observational study of 50,635 troops. The results of the study, according to BMI levels, found that 56.7% of the troops were overweight and of those individuals, 12% were obese[9].

In a study published in 2022, the French military conducted a study between September 2016 and April 2017 of 1,589 service members and found the prevalence of being overweight or obese was, respectively, 38.7% and 10%. Age, sex, weekly fitness activity, and rank were significant independent predictors of excess body weight. The study found that the rates were lower than most other nation’s militaries[10].

The Australian Army

Like other militaries, the ADF is not immune to the obesity issue. Recently the ADF came up with a novel approach to measure obesity levels in Army. This involved using uniform waist size as a proxy to estimate the number of members that were overweight or obese. Army had been progressively replacing combat uniforms with a new camouflage uniform since 2016. The total number of combat uniforms issued by size was obtained from three Army Combat Brigades, from the first issue of the new uniforms in 2016 through to 2019. The waist size of issued combat pants was collated and adjusted for measured waist size and sex, and then analysed to estimate the proportion of overweight and obese soldiers.

The results were that for a total of 155,735 combat pants issued the average waist size, based on combat uniform pant size, was found to be 90.4 cm. From this data it was estimated that around 23.3% of Army personnel could be overweight and around 4.5% obese[11][12]. To have around 28% of our Army overweight or obese is not ideal and needs attention.


Being overweight or obese is an issue for our nation as well as Defence. If overweight and obesity trends continue as they are, this could affect Army’s recruitment, manning, and operational capability – which is a risk to Army. National and Defence programs aimed at addressing this issue need to be developed and implemented to combat this growing issue.