Over the past few decades, researchers have shown that an individual’s
genetic makeup can play a big role in his or her propensity to gain weight and keep it on. For instance, one person may have a gene that makes him more efficient at converting food calories into body fat, while someone lacking this gene can apparently eat as much as she wants without packing on a single pound. Maddening for some, to be sure. But now it seems that dietary choices may have the power to override certain genes associated with body weight.
A watershed investigation in The American Journal of Clinical Nutrition found that a higher-quality diet—as measured by how people scored on the Alternative Healthy Eating Index 2010 (AHEI-2010), the Alternative Mediterranean Diet score (AMED) and the Dietary Approach to Stop Hypertension (DASH) diet score—was able to weaken a genetic predisposition to being chubby. So, a diet replete with nutrient-dense whole foods may be able to modify gene expression (epigenetics) in favor of promoting weight loss and keeping trim. This means people can’t always blame their genes when their jeans feel too snug.