For decades, health and nutrition experts have built weight-loss programs around the commonly-accepted notion of balancing calories in and calories out. In other words, to lose weight, one simply needs to burn more calories than he eats. But there is growing evidence that’s only part of the equation for losing and maintaining a healthy weight.
The Journal of the American Medical Association published a fascinating article last month that describes the biological drivers of weight gain. While it’s not a systematic review, the article references the evidence on the causes of weight gain and obesity. And it raises the questions of whether weight loss programs have been treating a symptom, rather than the cause, of obesity.
The New York Times summed up the question perfectly in an opinion piece on the JAMA article: “What if it’s not overeating that causes us to get fat, but the process of getting fatter that causes us to overeat?”
This issue is notable for two reasons. First, it raises an alternative and compelling lens through which we can view healthy eating: the western diet has triggered fat cells in our bodies to store extra calories. This means that fewer calories are available for our bodies to use as energy, so we feel more hungry. Then we eat more, and our bodies store even more of those extra calories as fat. On the flip side, reducing the amount of food we eat sends a signal to our bodies to store even more calories as fat, and we feel even hungrier. You can see how this mechanism could lead to the fad dieting that is so common in developed nations.
The issue is also notable for another reason: It’s a great example of using the available evidence to inspire new research. While the JAMA article isn’t a systematic review, it looks at the body of evidence on the topic of weight loss – from biological studies of the metabolism to large scale diet studies – to develop a hypothesis and ask new questions. Building new research on existing evidence is an excellent way to focus resources and delve into new areas. Hopefully ten years down the road, we’ll have enough evidence to publish a systematic review on new weight loss methods that can guide millions of adults to a healthier lifestyle.
Until then, what’s the best way to diet and lose weight? Unfortunately, we don’t know the answer yet. But a common thread that comes up in most of the research on weight loss is eating a varied diet that includes plenty of fresh fruits and vegetables. Is counting calories meaningless? Probably not. But, according to the JAMA article, the quality of your diet likely has an important impact on your weight.