CBC News profiled a study which showed that exercise does very little to help us lose weight. Apparently as we exercise more and more, our body finds new efficiencies in our movement so that it doesn’t need to cut into our fat stores. There are still many benefits to regular exercise, but we can’t lose weight by exercise alone; we need to change the way that we eat in order to have a more radical and lasting change in our bodies.
Aside from this being a fascinating revelation about how miraculously efficient our bodies can be, it also has two analogies for sustainable living: one about efficiency, and another about eating.
Efficiency is a wonderful thing, and something that we must strive for if we’re ever going to live sustainably – nothing should be wasted! But numerous studies have shown that if we increase, say, energy efficiency in light bulbs, people just turn on more lights. We tend to use as much energy as we can afford, whether we need it or not. So while our bodies find new efficiencies to lower our biological energy use, we find new energy use in proportion to our increased efficiency. We do this because our brains are wired for a scarcity mindset: if a resource appears to be limitless, we’ll use every bit of it; if a resource appears to be scarce, we’ll fight to use every bit of it ourselves. In this way, our minds and bodies work together to get as much food stored in fat as possible in case we run out. What we need to do, then, is deliberately adopt a functionality mindset to replace our scarcity mindset: how much light do I actually need right now? We need to make our minds more like our bodies, but it takes constant effort. But we can either expend the mental effort to live efficiently, or use market or tax mechanisms to increase the cost of energy. I’d prefer to live functionally than pay more for extravagance.
The other lesson from this revelation that exercise doesn’t make body fat disappear is that we need to change the way we eat in order to make lasting change. The same is true for sustainable living. Agriculture accounts for 70% of global water use, and uses sixty times more land than all urban and suburban areas combined. With an increasing population, we need to increase food production by as much as three times over the next century, but the system is already unsustainable. Agriculture is also one of the largest sources of greenhouse gases and water pollution. If we want to live sustainably, we need to change our diets – and we can start by simply eating less: less meat, less dairy, less sugar, and less altogether. A balanced diet is possible, but terribly uncommon!
Eating is a political act: every meal affects others – and our waistlines. To live lightly, and longer, eat lightly.