We have all heard that weighing yourself once a day helps control weight, that you can lose 20kg in five years by walking a mile a day, or that people who eat breakfast are thinner. But as the New York Times points out, most of the popular weight loss theories don't actually have a lot of research behind them.
Picture: Paul H/Flickr
For example, take the idea that people who eat breakfast are thinner. It turns out a solid study hasn't actually been done on this idea:
It is commonly thought, for example, that people who eat breakfast are thinner. But that notion is based on studies of people who happened to eat breakfast. Researchers then asked if they were fatter or thinner than people who happened not to eat breakfast — and found an association between eating breakfast and being thinner. But such studies can be misleading because the two groups might be different in other ways that cause the breakfast eaters to be thinner. But no one has randomly assigned people to eat breakfast or not, which could cinch the argument.
However, he idea still makes sense, which is exactly why it gets spread:
As he delved into the obesity literature, Dr. Allison began to ask himself why some myths and misconceptions are so commonplace. Often, he decided, the beliefs reflected a "reasonableness bias." The advice sounds so reasonable it must be true. For example, the idea that people do the best on weight-loss programs if they set reasonable goals sounds so sensible.
The truth is that there is little evidence to actually prove which method is the best when it comes to losing weight. The myths debunked by the researchers include:
- That small changes in energy intake or expenditure produce large, long term changes (it doesn't).
- Rapid weight loss is associated with poor long-term weight loss outcomes (people can in fact successfully lose weight quickly and keep it off).
- Setting realistic goals for weight loss is important because otherwise people get frustrated and lose less weight (realistic goals are often too modest).
Of course, many of these myths aren't exactly debunked, they are just unproven and don't have the research to back them up. Few weight loss studies have a solid, randomised group of participants in a controlled experiment. For now, it's probably best to stick to the weight loss techniques science has proven to actually work.
Myths of Weight Loss Are Plentiful, Researcher Says [New York Times]