If you normally eat something small (or nothing at all) before rushing off to work, then have a decent-sized lunch and a hefty supper, consider reversing your menu. According to a new study published in the Journal of Nutrition, people who make breakfast their largest meal, then eat lighter for lunch and even lighter for dinner, typically weigh less than those who, like many of us do, follow the opposite plan.
To learn this, researchers analyzed the dietary habits of more than 50,000 Seventh Day Adventists over a seven-year period. Members of this religion tend to avoid alcohol and cigarettes, eat very little meat, and exercise regularly, making them the ideal fit for dietary studies.
The people who ate breakfast tended to have lower body-mass indexes than those who skipped a morning meal, which is right in line with a strong body of previous research. But on top of that, regardless of total daily caloric intake or individual food choices, the people who ate a large breakfast and then tapered their meal sizes throughout the day—or even ditched dinner altogether—weighed less those who feasted at night.
There are multiple explanations for these findings. “First of all, physiologically, insulin action is most effective in morning, meaning we burn those most calories from meals in the morning,” says study co-author Dr. Hana Kahleova, director of clinical research at the nonprofit Physicians Committee for Responsible Medicine. “Due to hormonal changes that occur throughout the day, if you eat the exact same meal morning, noon, and night, the most fat will be deposited in your body after the evening meal.”
Another factor, says Kahleova, is many traditional breakfast foods, like oatmeal and cereals, are plant-based, so they’re high in fiber and antioxidants, which can help keep weight in check. But if you skip breakfast, you’re probably not eating oatmeal for lunch or dinner, so you’d be missing out on the nutritional benefits of this food altogether.
Kahleova says our bodies’ responses to certain foods and the times at which we consume them is hard-wired through our genes and cues off of our circadian rhythms. “We have a central body clock in our hypothalamus and that responds to the light-dark cycle,” she explains. “It needs to be synchronized with our peripheral clock, which is in every cell in the body.” Kahlevoa says that both eating a big breakfast and consuming plant-based foods help synchronize these clocks, whereas both chowing down at night and eating the typical Western diet desynchronize them. This disconnect can lead to weight gain, diabetes, and other health issues.
The irony of these findings is that our ancestors knew the big-breakfast-small-supper program was best. “It’s so funny,” Kahleova says, “we do so much research and still end up with the ancient proverb: Eat breakfast like king, lunch like prince, and dinner like a pauper.”