You can eat three meals a day – modern life is designed around this way of eating. We are told that breakfast is the most important meal of the day, we take our lunch break at work, and then our social and family lives revolve around dinner. Before considering how often we should eat, scientists encourage us to consider when we shouldn’t eat, reports Future.
About intermittent fasting
Intermittent fasting, in which you limit your food intake to an 8-hour period, is becoming a vast area of research. Emily Manoogian, a clinical researcher at the Salk Institute for Biological Research in California and author of a 2019 paper titled “When to Eat,” says:
Give our bodies at least 12 hours. every day without food.
Rozalyn Anderson, an associate professor at the University of Wisconsin College of Medicine and Public Health, USA, has studied the benefits of calorie restriction, which is associated with reduced levels of inflammation in the body.
“Fasting daily can reap some of these benefits,” she says. “It goes into the idea that fasting puts the body into another state where it’s more ready to repair and track damage, while also getting rid of the folded proteins.” Folded proteins are faulty versions of normal proteins, which are molecules that perform a variety of important tasks in the body. Curved proteins are implicated in a number of diseases.
Intermittent fasting is more in line with how our bodies have evolved, Anderson argues. She says it gives the body a break so it’s able to store food and get energy to where it needs to be, and trigger the mechanism to release energy from our body stores.
Benefits of fasting
According to Antonio Paoli, professor of exercise and sport sciences at the University of Padova in Italy, fasting may boost our glycaemic response, which is when our blood glucose rises after eating. He claims that having a lower blood glucose spike permits you to retain less fat in your body.
“Our findings imply that eating a late meal and extending your fasting window has some beneficial consequences on the body, such as better glycaemic management,” Paoli explains.
Because of a process called glycation, it’s healthier for all cells to have lower sugar levels, Paoli says. This is when glucose binds to proteins and generates “advanced glycation end products,” which can induce inflammation and raise the risk of diabetes.
How many meals does this leave room for?
Some experts, notably David Levitsky, a professor at Cornell University’s College of Human Ecology in New York, suggest that eating only one meal each day is optimum.
“There’s a lot of research suggesting that if I offer you food or photographs of food, you’re more inclined to eat, and the more food is in front of you throughout the day, the more you’ll eat,” he adds.
This is due to the fact that before refrigerators and supermarkets, humans ate whatever food was available. According to culinary historian Seren Charrington-Hollins, we have only eaten one meal each day throughout history, including the Ancient Romans, who ate one meal at midday.
Isn’t one meal a day enough to keep us satisfied? Not necessarily, according to Levitsky, because hunger is often a result of a lack of food.
Increased blood glucose level
But Manoogan doesn’t recommend sticking to one meal a day, since this can increase the level of glucose in our blood when we’re not eating – known as fasting glucose. High levels of fasting glucose over a long period of time is a risk factor for type 2 diabetes.
Keeping blood glucose levels down requires eating more regularly than once a day, Manoogan says, as this prevents the body thinking it’s starving and releasing more glucose when you do eventually eat in response.
Instead, she says, two to three meals a day is best – with most of your calories consumed earlier in the day. This is because eating late at night is associated with cardio-metabolic disease, including diabetes and heart disease.
“If you eat most of your food earlier on, your body can use the energy you feed it throughout the day, rather than it being stored in your system as fat,” Manoogan says.
Eating too early
“When you consume calories while your melatonin level is high, your glucose levels skyrocket. Consuming a lot of calories late at night puts your body under a lot of stress since your body can’t retain glucose correctly if insulin is suppressed.”
And, as we all know, prolonged exposure to elevated glucose levels increases the chance of developing type 2 diabetes.
The concept of breakfast
This doesn’t mean we should skip breakfast altogether, but some evidence suggests we should wait an hour or two after waking up before we crack open the eggs. It’s also worth remembering that breakfast as we know and love it today is a relatively new concept.
“The Ancient Greeks were the first to introduce the concept of breakfast, they’d eat bread soaked in wine, then they had a frugal lunch, then a hearty evening meal,” says Charrington-Hollins.
Initially, breakfast was exclusive to aristocratic classes, says Charrington-Hollins. It first caught on in the 17th Century, when it became the luxury of those who could afford the food and the time for a leisurely meal in the morning.
“The concept today of breakfast being the norm [came about] during the Industrial Revolution in the 19th Century and its introduction of working hours,” says Charrington-Hollins. Such a routine lends itself to three meals a day. “The first meal would be something quite simple for the working classes – it might be street food from a vendor or bread.”
But after war, when availability of food diminished, the idea of eating a full breakfast wasn’t possible and a lot of people skipped it. “The idea of three meals a day went out the window,” says Charrington-Hollins. “In the 1950s breakfast becomes how we recognise it today: cereal and toast. Prior to that we were happy to eat a piece of bread with jam.”
So, the science seems to say the healthiest way to eat throughout the day is to have two or three meals, with a long fasting window overnight, to not eat too early or too late in the day, and to consume more calories earlier on in the day. Is this realistic?
Best times to eat
Manoogan says it’s best to not specify the best times to eat, as this can be difficult for people with responsibilities and irregular time commitments, such as those working night shifts.
“Telling people to stop eating by 7pm isn’t helpful because people have different schedules. If you try to give your body regular fast nights, try to not eat too late or early and try to not have huge final meals, this can usually help. People can at least adopt parts of this,” she says.
“You could see a dramatic change just from a small delay in your first meal and advancing your last meal. Making this regular without changing anything else could have a big impact.”
But whatever changes you make, researchers agree that consistency is crucial.
“The body works in patterns,” says Anderson. “We respond to the anticipation of being fed. One thing intermittent fasting does is it imposes a pattern, and our biological systems do well with a pattern.” She says the body picks up on cues to anticipate our eating behaviours so it can best deal with the food when we eat it.
When it comes to how many meals we deem normal, Charrington-Hollins is seeing change on the horizon.
“Over the centuries, we’ve become conditioned to three meals a day, but this is being challenged now and people’s attitude to food is changing. We have more sedate lifestyles, we’re not doing the level of work we were doing in the 19th Century, so we need fewer calories.”
“I think, long-term, we’ll be reducing back to a light meal then a main meal, depending on what happens work-wise. Our working hours will be the driving force.”
“When we came off rations, we embraced three meals a day because there was suddenly an abundance of food. But time goes on – food is everywhere now.”
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