Fitbits and other wearables have fuelled a step-counting obsession. Photo / 123RF
Fitbits and other wearables have fuelled a step-counting obsession. Photo / 123RF
The 10,000 steps a day idea has become one of the popular health mantras of the past decade, with the emergence of Fitbits and other wearables fuelling a step-counting obsession.
However, while the World Health Organisation, the American Heart Association and many others have all adopted the 10,000 steps aday goal, the number is actually completely arbitrary, originating in a Japanese boardroom in the 1960s. Few people realise that the company Yamasa simply dreamt up the figure as a way of promoting the world’s first step counter ahead of the 1964 Tokyo Olympics.
Instead, actual research has suggested that between 6000 and 8000 steps per day might be the sweet spot for avoiding chronic illness. A new study published by scientists at the University of Alabama at Birmingham School of Public Health has found that if you live a fairly sedentary life, adding just 500 steps a day will bring significant health benefits.
“People obsess over how many steps are enough, but we should be asking how many steps are too few,” says Catrine Tudor-Locke, a professor and physical activity researcher at the University of North Carolina at Charlotte, who has studied the 10,000 steps a day phenomenon. “We should get people to stop taking less than 5000 steps a day, but there seems to be an obsession with the higher number, while it’s more important from a public health point of view to just get people off the couch and out the door.”
10,000 steps a day is just one of many public health doctrines that are grounded more in myth than actual science. Here are some others:
Perhaps the best-known piece of public health advice of all time, first conceived by the UK government in the late 1980s with the aim of encouraging people to eat more dietary fibre – the plant-based carbohydrates found in fruit, vegetables, cereals, nuts and seeds.
But in fact, studies have shown that five a day are unlikely to be enough to give us full protection against various chronic illnesses. One study from nutritionists at Imperial College London found that we would probably need to eat seven or even 10 a day to provide our body with all the nutrients and fibre we need.
Charlotte Evans, a researcher in nutrition and public health at the University of Leeds, says there needs to be a push for people to make fibre the majority of their daily diets, rather than processed foods. “When the dietary recommendations were originally set, it was designed as the optimal to prevent weight gain in the first place,” she says. “But now we’re in a situation where two-thirds of the population are already overweight.”
The 'five a day' mantra was first conceived by the UK government in the late 1980s. Photo / 123RF
Eight hours’ sleep
The idea that everyone needs eight hours of sleep per night goes back to Victorian England. At the time of the industrial revolution, a daily regime of eight hours’ labour, eight hours’ recreation and eight hours’ rest was commonly prescribed.
But we now know that the amount of sleep we require is highly individualised, and is dictated by a complex mix of genetics, age, medical conditions and lifestyle. Some people can function perfectly well on less than six hours, while others need more than 10 hours to feel at their best.
According to Russell Foster, professor of circadian neuroscience at the University of Oxford, individual sleep patterns are akin to shoe size. “I think that the myth of the eight hours has actually caused quite a bit of anxiety,” he says. “There’s actually a huge amount of variation.”
Two litres of water a day
Two litres of water per day, or approximately eight glasses, has been standard advice for decades, but our fluid requirements actually vary a lot depending on how much exercise we do, the weather, climate and age.
Depending on circumstances, people may need as many as six litres, if they are working out a lot in hot weather, or as little as one. Various online hydration calculators attempt to give you an idea of what your daily water intake should be, based on a short questionnaire.
According to Dale Schoeller, emeritus professor of nutritional sciences at the University of Wisconsin-Madison, the science has never supported the two-litres-a-day rule as an appropriate guideline. “A lot of your water comes from the food you eat,” he says.
Breakfast is the most important meal of the day
Our modern-day obsession with breakfast goes back to the 1920s, when early marketing campaigns from cereal companies placed a big emphasis on the supposed healthiness of breakfast. As people became more and more preoccupied with the concept of vitamins, savvy cereal brands began touting the nutrient content of their products, while in recent decades claims have even been made that breakfast might help you lose weight.
But whether breakfast is even necessary remains up for scientific debate, while nutrition experts say that its health benefits depend on what you are actually eating. A breakfast consisting of highly processed foods and a large sugar content is likely to do more harm than good.
“The evidence that eating breakfast helps you lose weight largely comes from studies where there’s a suspicion that those people might be eating more healthily in general,” says Kevin Murphy, a professor who researches metabolism and digestion at Imperial College London. “Other studies have suggested that in trials where you are asking people to change whether they eat breakfast or not, in fact breakfast is likely to drive people to eat more calories during the day.”
2000 calories a day
According to the UK’s National Health Service, the recommended daily calorie intake is 2000 calories a day for women and 2500 for men.
But, as with sleep and water intake, our calorie needs depend on many factors, including age, gender, height, weight and physical activity levels. Some people will need to reduce or increase their calorie intake in order to maintain a moderate weight.
Many dietary experts are questioning the relevance of the calorie fixation in our diets because not all calories are created equal.
As Giles Yeo, professor of molecular neuroendocrinology at the University of Cambridge, pointed out in his 2021 book Why Calories Don’t Count, the body absorbs the calories present in various foods very differently.
“Calories don’t take into account the energy it takes our cells to metabolise food in order to use it,” he says. “A calorie of protein makes you feel fuller than a calorie of fat, because protein is more complex to metabolise. You could be aiming to eat 2000 calories a day, but how much energy your body actually absorbs will depend on whether you’re eating sugar, celery, or steak.”
