So you diligently work on your health and fitness, exercise regularly, stick to your diet plan and try get the right amount of rest to maintain a balanced, healthy lifestyle, and drop some excess weight in the process.
And then along comes… another study.
Scientists have found yet another way we get fat and overweight – as if there weren’t enough already. It seems that if we are exposed to environmental light for long enough (the kind we get in the modern offices, work spaces and homes) it can trigger our bodies into becoming less efficient at burning energy, with the inevitable result of storing more fat.
The study, reported in the Proceedings of the National Academy of Sciences of the USA (or PNAS) states that “Increased light exposure has been associated with obesity in both humans and mice”. It suggests this happens because our circadian rhythm (the natural rhythm in our body that controls physical, mental and behavioural changes over a 24-hour period, regulated mainly by light or darkness) is disrupted, which results in our bodies not expending as much energy as they would normally do, which promotes weight gain.
They specifically highlight the correlation between this study and weight gain: “Disruption of circadian rhythmicity is associated with obesity and related disorders, including type 2 diabetes and cardiovascular disease”
It’s all about Mice and Men
The study explains that this behaviour was noticed when mice were exposed to artificial light for a set number of hours over a 5 week period. The results clearly showed that the mice were exposed to the light the longest had a ‘significantly higher fat composition’ even though the diet was the same for mice that were exposed to this type of light for a reduced time.
It seems the problem with being exposed to environmental light for prolonged periods is that our body’s natural rhythm gets confused. This ‘confusion’ leads to weight gain as a direct result of our bodies starting to use less energy, rather than other factors such as an increase in our appetite, or feeling we need to moderate physical activity.
To get a bit more technical, this decrease in energy burn by our body was thought to be down to the light adversely affecting the activity levels of brown adipose tissue (BAT) – a tissue in the body which plays an important role in converting energy from food into heat. So basically the more light we are exposed to, the less efficient this tissue worked, resulting in our bodies converting less energy. And we all know what the body does with unconverted energy from food – it conveniently stores it for later… mainly around the belly. As fat.
So what does this mean for us in real terms? Well, if nothing else, it’s a good stimulus to get us off our butts for a start, and get out more into the natural light and into nature. At the very least this will get us physically moving. How much exactly this exposure to artificial light adds to your waistline is difficult to say, but one things for certain – sitting around any environment with artificial lighting for long periods of time can’t be healthy for anyone’s body, anyone’s mind, or anyone’s soul.