Shocking as it is, there is a glut of bad weight loss advice on the internet. So when scientists take time out of their busy schedules to correct the internet on this very important subject, the very least I can do is promote their research, since shutting down HuffPo Healthy Living isn't an option.
Writing in the New England Journal of Medicine last week, researchers from the University of Alabama took on a handful “obesity-related myths and presumptions” (seven myths and six presumptions, respectively) which they say are believed by experts and laymen alike. . The paper's authors searched the internet for these 13 bits of silliness and then analyzed each one to see if it stood up to scrutiny.
You can check out the full list of myths in the paper's abstract, but here is a breakdown of the three worst and most widely believed offenders in my view, though my reasoning may be slightly different than the researchers'.
1. Eating less and exercising more is the key to losing weight.
Also known as the “calories in-calories out” hypothesis, this assertion has always been untrue. The evidence tells us that our bodies don't treat all calories the same, because the macronutrients in our food are metabolized differently. Thus, a salad and a Snickers bar may contain the same number of calories, but one is undeniably healthier than the other.
This presupposition is the most problematic on the list because most diets use it as a foundation, which means most dieters are starting with bad information. The result is mass failure to achieve weight-loss goals.
2. Eating fruits and vegetables will make you slimmer.
Fruits and vegetables are good and good for you, especially Granny Smith apples. Yum. But they may not encourage weight-loss, according to the NEJM study. The common wisdom suggests that fruits and vegetables are good snacks because they contain fiber, so they keep you full longer and encourage you to eat less. But as one of my favorite health bloggers, Dr. John Briffa, explains, this claim is “largely bullshit.”
A team of researchers said the same thing last November in the International Journal of Obesity, albeit using more scientific language. They found that regularly consuming fruit, whether solid fruit or fruit juice, didn't encourage people to eat less. According to Briffa, the study participants actually ate more.
3. Healthy, thin people eat breakfast, and so should you.
The idea that eating breakfast everyday helps dieters is widespread. Regular morning meals are thought to keep you from gorging later on in the day to replace the calories you should have eaten earlier. There are some studies (funded by cereal companies, wouldn't you know it) that support this idea, but most of the evidence contradicts it.
Multiple studies have found that meal frequency has no impact on weight-loss. There is an association between eating breakfast and weight-loss; the relationship is better explained by the fact that people with overall unhealthy eating habits tend to skip breakfast, or that overweight people often skip meals as a way to slim down.
Either way, eating breakfast doesn't have some magical effect of your metabolism.