The Age-Old Diet Wisdom That May Actually Be Making You Gain Weight

Chances are, you've heard this classic bit of diet wisdom countless times in your life: "everything in moderation." But a new study suggests that this mindset is flawed, and could actually be contributing to weight gain — what gives?

According to recent findings published in PLOS ONE, the "everything in moderation" mindset contributes not only to weight gain but also to an increased risk of diabetes over 10 years. Turns out, diversity in your diet isn't the cure-all we were led to believe. Researchers asked over 7,000 people to identify their eating habits, paying particular attention to the number of different types of food consumed in a week and how alike those foods were, nutritionally speaking.

Their findings fly in the face of this often-repeated diet mantra. Those who consumed the widest variety of foods were found to have a 120% greater increase in waist size over those who didn't, and were more likely overall to gain weight than those who held fast to a few tried-and-true recipes (regardless of how healthy those recipes actually were). "'Eat everything in moderation' has been a long-standing dietary recommendation, but without much empiric supporting evidence... We wanted to characterize new metrics of diet diversity and evaluate their association with metabolic health," comments Marcia C. de Oliveira Otto, Ph.D.

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But weight gain was only the beginning of their findings. "An unexpected finding was that participants with greater diversity in their diets, as measured by dissimilarity, actually had worse diet quality. They were eating less healthy foods, such as fruits and vegetables, and more unhealthy foods, such as processed meats, desserts and soda," says Otto. It's an interesting issue — one can see how all manner of dietary sins could be hidden under the umbrella of "everything in moderation".

This might be one realm where less really is more. According to Dariush Mozaffarian, M.D., Dr.P.H., senior author and dean of the Friedman School of Nutrition Science and Policy at Tufts University in Boston, "Americans with the healthiest diets actually eat a relatively small range of healthy foods."

The takeaway? Focus on filling your diet with a concise number of high-quality foods you really enjoy and go from there. As it turns out, "everything in moderation" may translate to covertly giving yourself permission to overdo it on unhealthy snacks.

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