Multiple researchers at Osaka University observed health records from 17,573 male and 8,860 female students (age 18 and older) over the course of three years and found that study participants who regularly skipped dinner were likely to gain weight or be overweight.
Dinner skipping was found to be the main commonality among 10.8% of the male study participants who gained weight and the 17.1% of the female study participants who gained weight.
Ditching dinner was more "associated with overweight/obesity in men and women, respectively" than breakfast and lunch did, according to the study’s findings.
For the male and female participants who gained weight during the study, a significant number were said to likely be older, more overweight, sleep less, drink or smoke more and skip other meals more frequently than those who ate dinner on a regular basis.
Unlike their female counterparts, the male students who gained weight were also likely eat dinner later than those who did not gain weight – or at least that was the case whenever they chose to not skip the evening meal altogether.
Both sexes, though, were found to be "significantly associated with ≥10% weight gain and overweight/obesity (BMI ≥ 25 kg/m2)."
For reference, a body mass index of 25 ranges between 119 and 205 pounds depending on a person’s height, according to a BMI table published by National Heart, Lung, and Blood Institute.
However, the weight-focused health metric does have a limitation when it comes to muscle versus fat, which could mistakenly classify an athletic person as overweight if muscle mass is not accounted for.
Researchers do not completely understand why dinner skipping appears to contribute to weight gain. Though, they have theorized the correlation between the two could be due to "an excess of energy intake" that can occur with an unregulated appetite.
In other words, skipping dinner could mean a higher hunger threshold, which could consequently cause a person to eat more than they usually would.
Further studies on the topic need to be conducted, but researchers were able to come up with a hypothesis for dinner skipping and its potential relation to weight.
"The present retrospective cohort study identified skipping dinner as a significant predictor of weight gain and overweight/obesity," the study stated in its conclusion. "These results suggest that dinner frequency may be a critical lifestyle factor for the prevention of obesity in addition to breakfast frequency."