We’re eating less junk food, so why is obesity still on the rise?

The Medibank Better Health Index¹ (MBHI) revealed that as a nation, we’re healthier than we were 8 years ago. We’re exercising more, eating better and drinking and smoking less. But despite this, our BMIs² have worsened over time, with obesity levels on the up.

How much have BMIs gone up by?

The average Aussie is about 300 grams heavier today than in 2007-2008³. The mean BMI has gone from 27.09 then to 27.20 today, with both scores sitting in the overweight range.

While this increase might seem small, it’s surprising when considering factors like physical activity and the intake of junk foods like fast food and sweets have shown a better health trend in this same timeframe.

So why is obesity on the rise? We asked Dr Tim Crowe.

Obesity is a complex issue, and it’s not just about junk food and lack of exercise. Poor sleep patterns, pollution, certain medications, increasing birth age and even our climate-controlled living environment have all been linked to weight gain. Will all of these factors cause a person to gain weight? Not for everyone, but they can each add up over time when you look at the population’s collective weight. Another aspect that gives some potential insight into our national weight gain is our improved smoking health. Smoking is one of the world’s leading causes of illness and death, and our falling smoking rate is certainly great news, but one side effect can be weight gain. That said, small changes to diet and physical activity easily offset the slight amount of weight gained after quitting.

So where does this leave us?

While diet and exercise certainly play critical roles, there are many lifestyle factors that contribute to the rising obesity trend. And while BMIs are indeed increasing, we’re still seeing a trend towards better health overall, which is reassuring.

Understanding weight loss and obesity can feel complex –but you could get some help wading through the minefield of myths.