No sooner have we mastered exercise and eating – by which I mean we’re eating the rainbow, walking daily and lifting a few weights – than those pesky scientists discover it’s timing that matters.
OK I exaggerate. But recent studies suggest that when we move is almost as important as how we move, with new studies finding the same applies to our eating. Optimising the timing of our meals and movement is known as chrono-nutrition and chrono-exercise, and scientists are only just beginning to unravel why this matters.
At the Age-Well Project we don’t like to make our lives any more complicated than they already are. So today I’ll cover a couple of reports with two easy-to-make tweaks to our daily lives that could make a significant difference to our healthspan and our wellbeing.
Let’s start with our consumption of protein. We’ve written before about the need for more protein as we grow older. Protein is vital for cellular growth and for muscle building. However, a new report suggests that protein has a much greater impact on our muscles if we consume it earlier in the day. We know this goes against our cultural grain – many of us eat a carb-heavy breakfast (toast, porridge, cereal, croissant) and a light lunch (soup, salad and bread is a favourite of ours) and then a protein-rich supper. The evening meal is often when we eat with family or friends, typically lavishing more care and expense on this meal than on any other.
But new research suggests we might want to re-think this. Protein metabolism is affected by our internal biological clock (also known as our circadian rhythms), which means we digest and absorb it more effectively at certain times of the day. And it turns out that – if we want to improve the size and functionality of our muscles – breakfast or earlier in the day is the best time to consume protein.
And for anyone who thinks muscle doesn’t matter, let me refer you to earlier posts where we’ve reported on the role of muscle in maintaining everything from eye health to mental health. Muscle is not just for body builders: indeed muscle is more important that we ever knew. But here’s the thing – from the age of 30 our muscles go into decline, losing 3-5% each decade. The older we get, the more we must pay attention to our muscles.
In a study published last week, researchers found that morning consumption of protein lead to better performing muscles in mice. They then replicated the study on sixty women aged 65 and over. The women adjusted their protein intake so that it was consumed at breakfast rather than in the evening. Hey presto! Their muscle size and function improved!
According to Professor Shibata who led the studies “Protein-rich diet at an early phase of the daily active period, that is at breakfast, is important to maintain skeletal muscle health and enhance muscle volume and grip strength.”
Grip strength, incidentally, is one of the biomarkers of our overall health and a test regularly used by doctors to check how well we’re aging.
Prof. Shibata added, “For humans, in general, the protein intake at breakfast averages about 15 grams, which is less than what we consume at dinner, which is roughly 28 grams. Our findings strongly support changing this norm and consuming more protein at breakfast or morning snacking time.” Incidentally 28 grams of protein equates to 2 large eggs.
This has thrown us into a bit of a quandary: Susan and I both favour a version of intermittent fasting that involves a long overnight fast. But am I making changes as a result? Yes I am. I’m shifting my evening protein to my early lunch. There’s a second compelling reason for this – and it’s to do with sleep.
Professor Andrew Huberman, one of my favourite neuroscientists, says we sleep better when we eat more carbs at our evening meal. In order to have a long overnight fast he doesn’t eat breakfast, but he eats plenty of protein at lunch and then plenty of carbs in the evening to ensure a solid night of sleep.
Of course, we’re all different. But in terms of evolution it makes sense that we metabolise protein more efficiently in the earlier part of the day. To quote the pioneering geneticist, Theodosius Dobzhansky, ‘nothing in biology makes sense except in the light of evolution.’ And we evolved to hunt, forage and move with the sun. Besides, at night our brain and body are busy doing other things (of which, more in the autumn).
So how about movement? Well, it turns out that when we move can have benefits too.
During lockdown, without a social life to accommodate and with no desire to look at a screen after a day’s work on my laptop, I began taking evening walks. I’d been inspired by my lengthy investigations into the historical habits of walking women. To my surprise I’d found that women routinely walked after dark. The Scottish walker and writer, Nan Shepherd, called them her ‘night prowls’; the Welsh painter Gwen John believed she came most fully to life on her nocturnal saunters; the Australian-born writer Clara Vyvyan wrote lyrically about her evening walks beside the River Thames; Dorothy Wordsworth, 200 years back, wrote ‘I am particularly fond of a moonlight or twilight walk.’ Every woman, it seemed, had been out strolling at night.
No television. No Netflix. No surprise really. So I began researching the benefits of walking after eating, with a special interest in walking after supper. And it turned out that short after-dinner promenading (nothing more vigorous please) brings many, many benefits. It reduces gas, bloating and constipation. It aids, eases and stimulates our digestion, ensuring efficient delivery of nutrients round our bodies.
After-supper strolls boost heart health (as any movement does) but they also reduce blood sugar spikes that accompany large meals. Several studies found that a gentle walk after eating helps regulate blood glucose levels, making it particularly effective for anyone with Diabetes (type 1 or 2).
Lastly, by exposing ourselves to darkness we encourage our body to begin producing the melatonin necessary for good sleep. We talked on our recent webinar about the importance of morning light to set our circadian rhythms. But walking after supper, as the light drains from the sky, sends an equally powerful message: time for sleep! Studies show that walks taken later in the day increase the amount of slow-wave (deep) sleep that is particularly necessary for cellular rejuvenation and for protecting against Alzheimer’s.
As ever, listen to your own body. If you feel discomfort, wait for a bit. And remember this is a gentle amble not a power walk.
Put your safety first: choose a safe route or take a friend, and make sure you can be seen by any cars (I wear a head-torch in the country and stick to well-lit streets in the city).
If anyone fancies some vicarious strolling around the world, I’ll be talking about Windswept Women and my routes in Scotland, France, the Alps, Texas and New Mexico, at the world’s most famous travel bookshop (Stanford’s in London’s Covent Garden) on 4th August at 6.30. Tickets available here, and each one includes a glass of wine or soft drink, and is fully redeemable against the price of the book (which I’ll be signing In Real Life). It would be lovely to see you there!
I’ll leave you with one further report from the American Academy of Neurology published last week that found older people who read, write letters and play games can delay Alzheimer’s by five years. If, like Susan and I, you’re having a staycation, why not treat yourself to a new game, a few books and some new letterhead or a new pen? I can’t think of a nicer way of staving off dementia! You can read more here.
We’re offline for August, but back in September with lots more news and recipes. Have a wonderful summer…