A patient asked me “I only eat one meal a day, a kind of late breakfast. Is that bad?”
“No,” I replied.
He’s a physically healthy man. Though pretty lean, he worries about his weight. I explained that in Army experiments where biddable privates were given only a single, 2000 calorie meal each day, those who ate in the morning lost weight; those who dined at lunch maintained weight; those who ate at night gained weight.
That was the 1960s. An excellent recent article by Roni Caryn Rabin demonstrates that we are once again rediscovering the past: when it comes to weight (and much else) when you eat may matter as much as what.
Cultural norms need not fit human biological design. Oftentimes they do, all too well.
A Hunger Gatherer Walks Into A Supermarket
Supermarkets are not bars. But they can feel like bars.
There are opportunities for socializing. Extraordinary varieties of things to buy. Friendly, knowledgeable salespeople (sometimes.)
Followed by a frenzied opportunity to eat and drink.
For little succeeds like excess. And lots of us can’t help ourselves.
Human history is a history of starvation, and our hunter gatherer bodies are primed to survive periods lacking food. About seventy thousand years ago there were not many of us left. Humanity almost starved into disappearance. And kept intermittently starving. Give us a chance to eat, and most of the time, we’ll take it.
Nevertheless, famines, pestilences, droughts, climate change, political conflicts and wars continue to test the human body’s capacity for starvation. Government controlled starvation remains a potent political tactic. Stalin used it in the twenties and thirties, wiping out millions. Mao tried it in the “Great Leap Forward,” killing tens of millions. Right now, hundreds of thousands starve in Yemen.
At home, obesity is perhaps a bigger problem.
Learning From the Past
A recent diet study of 50,000 Seventh Day Adventists, a healthy group which includes our present secretary of Housing and Urban Development, showed that eating breakfast correlated with lower weight. Eating more calories earlier in the day was associated with lower weight. Eating snacks brought weight gain.
So far, so well known. What was a little different in the Seventh Day Adventist study was found in the the people with the lowest Body Mass Index (BMI.) They ate one or two meals each day, but stopped eating by the early afternoon, not dining again for 18-19 hours.
Just like my patient.
In recent days, many “new” diets have proposed periods engaging “short” caloric restriction. Often these involve one or two days a week eating several hundreds calories less than the normal fare. Not uncommonly, people tell me these diets are not terribly difficult to follow. Which makes sense. There is nothing written on high determining when and how we should eat. Or sleep.
It’s just that certain patterns end up providing results we like a whole lot more.
Body Clocks and Weight
Time rules life. It also changes your weight.
Waking is a critical time for humanity. Before we arise our body prepares, revving up heart rate, platelet aggregation, cortisol and insulin.
By the time we get up, insulin production is in high gear. The result is that we’re a lot more able to metabolize breakfasts than any other meal.
Yet culture works against natural proclivities. The American “Lie Down and Die” model of sleep leaves little time for sufficient rest, and frequently insufficient morning time to prepare for school or work. The result – no breakfast or “Grab and go” snack breakfasts high on caloric density (not much time to gobble the food) and stuff we really love to eat (sugar and sugar, plus fat.) The high school student who starts class at 7:20 AM is particularly challenged, waking two hours earlier for cosmesis, checking of social media, bus and car commutes and brief, goal directed communications with similarly time stressed parents. So there should be little surprise that many high school and university students sleep through their morning classes. And with little sleep at night, making them prefer sugar filled, ravenous repasts, they frequently gain weight.
For body clocks do rule many of our physiological processes. While most are most powerfully set by timed light, they are also deeply affected by when we eat. That’s why jet lag experts tell you to time your travel meals to the destination you’re going to rather than one you just left. Odd meal times during travel produce more jet lag symptoms.
And not coincidentally, more weight gain.
Humans are built for intermittent starvation, but modern civilization in developed countries creates near endless opportunities to eat. Biological intelligence has built us with a physiological system that does best when we have nice, big, nutritionally varied breakfasts. They can help us control weight and perform well during the day.
Breakfast is for champions.