Trying to lose weight? This common mealtime mistake could be sabotaging your progress

Lifestyle choices impact your weight, but your genes can tip the scales, too.

New research suggests that people with a higher risk for obesity may be sabotaging their efforts to slim down by making a simple mealtime mistake. 

The good news? Scientists found an easy switch that can help fight back against what’s written in your DNA — and it’s not about changing what’s on your plate.

The study followed nearly 1,200 overweight and obese adults in Spain taking part in a 16-week weight-loss program. About 80% were women, with an average age of 41.

Researchers calculated each person’s polygenic risk score for body mass index (BMI) — a genetic measure of their obesity risk.

They also tracked when participants ate, splitting them into “early” and “late” eaters based on the midpoint between their first and last meals of the day.

After a 12-year follow-up, participants gained 2.2% more body weight for every hour that their meal midpoint was delayed.

The researchers also found a “significant interaction” between meal timing and genetic risk scores.

Over the study period, participants with a high genetic predisposition for obesity saw their BMI increase by more than 2 points for every hour they delayed eating. No such link was observed in those with lower genetic risk.

People with both a high genetic risk and later meal times had the highest BMI, while early eaters kept theirs lower.

“These findings suggest that early eating may be especially relevant for individuals with a genetic predisposition for obesity and not for others,” the study authors wrote.

The implications are serious.

Across the country, more than 100 million adults have obesity, and over 22 million have severe obesity, according to the Centers for Disease Control and Prevention.

This extra weight increases their risk for a wide range of chronic health conditions, including type 2 diabetes, heart disease, stroke, high blood pressure and even some cancers.

It also drives up healthcare costs. In 2019, adults with obesity spent an average of $1,861 more per year on medical care than those at a healthy weight. For those with severe obesity, excess costs topped $3,000 per person.

Without strong interventions, the problem is only expected to grow worse. While surveys have found that many overweight Americans want to slim down, research shows that conventional methods like calorie restriction often fail to keep the weight off long-term.

The study authors said that understanding the link between genetic risk for obesity and meal timing could pave the way for personalized prevention and targeted behavioral interventions in the future.

One example they highlighted is precision nutrition, which designs eating plans based on a person’s DNA, microbiome, and metabolic responses — moving beyond the one-size-fits-all approach.