Why So Many New Year's Weight Loss Resolutions Fail


Each year many Americans follow a predictable and unfortunate pattern. Between Thanksgiving and Christmas, they gorge themselves on delicious but unhealthy holiday food. Then, come January 1, they swear off their poor eating habits in the name of better health, only to fall back into them within a few weeks or months.

The dismal success rate of these New Year's diet resolutions is discouraging but it isn't particularly surprising, since 80% of all dieters fail to lose weight, and one-third even gain additional weight. But the upside to these depressing statistics is that they have given researchers the impetus to find out why losing weight is so difficult. So in hopes of keeping those resolutions alive, let's take a look at why so many well-intentioned weight loss efforts fail every January.

Perhaps one of the most important reasons why the failed New Year's diet has become such a cliché is that willpower is often no match for all the variables that influence eating habits. According to a 2009 study published in the journal Appetite, for example, the sheer complexity of most diet schemes, Weight Watchers in this case, may be enough to discourage many people from maintaining their weight loss efforts. The researchers found that the 390 study participants were more likely to give up their diets prematurely if they were “... not able to recall or process all required information for deciding what to eat.” Higher “self-efficacy,” the belief that they could lose weight, did encourage the participants to stay on their diets, but simplicity of the diet was still a better predictor of success. The researchers also noted that environmental factors, like keeping junk food around, could subdue willpower as well.

Such outcomes lead to an inevitable question: Why is willpower so useless when it's most needed? One possible explanation is that many people are predisposed to make poor choices. In 2009, scientists from Caltech found that the brains of people who have better self control may actually function differently. The researchers discovered that more activity in a region of the brain called the dorsolateral prefrontal cortex (DLPFC) enabled certain study participants to make better choices when selecting foods to eat. Admittedly, “You're wired to make bad decisions” isn't a very helpful explanation, but the goal now is to figure out how to engage the DLPFC in people who make poor eating decisions before they make them.

Studies in psychology and neuroscience like these may ultimately help explain why weight loss is an insurmountable challenge for many, but a related and arguably better explanation may be that dieting itself is actually the problem. In a 2011 Nutrition Journal article, a team of researchers argued that placing the emphasis on weight loss, as opposed to overall healthfulness, sets dieters up to fail. Encouraging people to modify their diets and exercise specifically to lose weight, though successful in the short term, often leaves people no slimmer or healthier than when they started, and frustrated that they can't reach their goals. By the way, that sounds exactly like what happens to many Americans each and every January.

But the most likely reason for this beginning of the year frustration is all the unworkable dietary advice available to overweight people. Whether some ridiculous fad diet promoted by the likes of Oprah or Dr. Oz, or the oversimplified calories in-calories out approach, bad dietary advice is the root of the problem. Many people may struggle to stick to a diet for various reasons, but the task is infinitely more difficult if the diet is premised on a stupid idea.

There's no doubt that permanently changing eating habits is difficult, but it is doable. There is clear evidence that people can successfully lose weight and keep it off, regardless of the psychological or genetic stumbling blocks that may be in their way. The key is making dieting decisions based on the available science. And it's certainly a strategy that could save people a lot of frustration come the first of the year.