December 18, 2014

Right now, social media is abuzz with the answer to the age-old question: “What happens to the fat when we lose weight?” And the answer is clearly not what most people expected.

Doctors, dietitians and fitness professionals have varying ideas of what happens to the fat (see here), but it turns out that none of them are really sure.

To summarise the results of a new study published this week in the BMJ, molecules of fat are biochemically broken down into carbondioxide and water, which means that we breathe it out and sweat or wee it out. It wasn’t exactly what we expected to learn.

It almost sounds too good to be true. All you have to do is breathe more and sweat more and you can lose weight? Hmm, sounds like exercise, and that’s just a bit too simplistic.

We know that exercise is great, but we’ve been talking for a long time about how exercise is not a great strategy for weight loss. It helps, for sure, and it’s a really important thing for people to do, but it’s not a great weight loss strategy.

Most people who carry extra weight are not gluttonous or slothful, but they may lack energy which makes exercise difficult. Their hormones may be contributing to their weight gain. Their gut microbiota may be contributing to their weight gain. Their high stress levels (which have a hormonal link), poor sleep (yet another hormonal link), genetic disposition (hormones again?), work environment, toxic overload, specific food choices, and a variety of other factors can all contribute to weight gain.

So the idea that breathing and sweating more, or exercising, is not the solution to being overweight. Sure, this might work for some when there are no other contributing factors, but the reality is that the study doesn’t explain how to lose fat, just what happens to the fat when it is lost.

It would be great if everyone who read this study resolved to start (and maintain) an exercise program. Many medical conditions would be improved, and those who were not already overweight would be more likely to maintain a healthy weight. Kids would have active role models to look up to, and people’s feelings of increased energy and well-being would be improved. There would be less sitting and more moving.

But we’d still have just as many people with weight problems, simply because the factors which cause the weight gain had not been addressed. Luckily, most of these factors can be influenced by food choices, so if you want to engage in exercise for weight loss, go right ahead and enjoy it, but ensure you also make the food choices that work for your body.