Last week, I wrote about why permanent daylight savings time like the golf industry is pushing in the Senate right now would be a disaster for our biological clocks. Since this coming weekend the clocks will “fall back,” now’s a good time to also look at how our shortening days influence when we should be eating dinner.
When I was growing up in Michigan, a lot of the farm families would have their biggest meal of the day at lunch with a light supper or dinner in the evening. I saw the same pattern when we lived in Germany in the 1980s, particularly in the small towns.
The big hot meal typically came at midday, and the evening meal was Abendbrot, literally “evening bread,” a plate of bread, cheese, and vegetables (meat for meat eaters) eaten early enough that you’d mostly digested it by the time you went to bed. I thought it was quaint but now, science finds, it turns out it was driven by physiology.
Deep in our brains there’s a cluster of cells that run our 24-hour internal clock, our circadian rhythm, and it’s mostly driven and set by cues from light and dark. In addition to telling us when to sleep and wake up, it sets the daily rhythm of digestion, hormone release, body temperature, and even how efficiently we burn what we eat.
Which is why when the light fades early in the winter evenings that wind-down starts earlier, too. Our dinner schedules, though, are typically driven by the clock and habit instead of the sun.
Researchers at Johns Hopkins’ sleep lab recruited young, healthy volunteers and fed them an identical dinner on two different nights, one at 6 pm and the other at 10 pm. Those who ate the later dinner saw their blood sugar peak 18 percent higher and stay elevated for four hours, while they burned roughly 10 percent less of the fat they’d eaten. Their overnight cortisol levels — the stress hormone — ran higher, too.
The researchers concluded that this double-whammy could help drive both obesity and metabolic syndrome, two conditions that can shorten your life.
And that was just in a single night. A 2024 meta-analysis in JAMA Network Open involving 2,,400 adults over 29 randomized trials found that people who ate earlier or kept their day’s eating in a shorter window modestly lost weight and saw blood sugar improvements.
Traditional cultures and societies have known about this forever, even if they lacked the scientific language to describe it. Around the world, early agrarian societies ate their biggest meal at midday and timed their evening eating to the sun. The same was (and still is, in many cases) true of monastic communities. The rest of us, though, traded that wisdom in for dependence on the clock.
Louise and I have been eating earlier in the winter for years, and when we were retired in the 1990s in Vermont even lit our home with oil lamps and tried to synchronize our eating and sleeping with the sun. It was a great time that I still remember fondly, and we’re still eating earlier and earlier as the winter comes on.
So, as the days get shorter, try moving your dinner earlier in the day if you can. Notice how you feel after a few weeks; if the research is right there should be a measurable improvement in your health and overall well-being.
Thank you! There is a reason our bodies intrinsically know what is best for it. Now if only our minds were on board. The rushed world we call "living" does not easily accommodate. A conscious awareness and effort makes the circle connect.
We certainly know this from our family members in Germany. They would talk about "eating cold" (Kalt essen) at night. Typically, this was a bit of bread and cheese or meat. We saw the pattern in full effect when we looked for a restaurant for an evening meal in Oslo. Most restaurants at that time, a few years ago, closed by 5:30 p.m. It was the tradition of the "middag", the last meal of the day, and it was typically served between 3:30 and 5:30 p.m. (15:30–17:30). In winter, the days in Norway are even shorter, with only 6 hours of daylight in the south, up to Arctic darkness in the north.
The Swiss follow the same pattern, with the main meal at midday, but add an interesting nuance. Time-of-use electricity rates were historically lowered between 12 noon and 2 p.m., so people can cook the noon meal at home because there are no school lunches. There was no similar lowering for the evening meal, as time-of-use higher rates usually extend to 10 p.m. The "liberalisation" of the electricity markets in Europe has eliminated this nuance, however.