Anti-salt lobby groups, diet professionals and governments want us to believe that any health improvements are the result of their public health interventions rather than drugs. For most healthy people, the reduction in blood pressure as a result of salt reduction is surprisingly small and clinically trivial
Eat less fat. Eat less sugar. Eat your five-a-day. Eat more starchy vegetables. Never skip meals. Eat little and often.
Drink at least eight glasses of water a day. Don’t skip breakfast. Drink less caffeine. Drink less alcohol. Eat less meat and dairy. Eat more fish. Do more exercise.
We have become used to being told how, when and what we should be eating. These messages come from many different sources: national guidelines, the media, advertising and even food labels and cereal packets, as well as posters and leaflets in hospitals and GP surgeries.
I am a scientist and a medical doctor. Yet, over the past eight years, I have been shocked by what I have discovered and am still uncovering. So much of what we swallow when it comes to advice about food is not backed up by science, while some of it can be categorically wrong.
But these myths are repeated so often that they can be hard to unlearn. They could also be the reason why many of us struggle to lose weight and keep it off.
In my research for this book, I set out to analyse everything we know – or think we know – about food and dieting. What I discovered not only shocked me but forced me to revise my opinions on most aspects of food and health.
Much of what we treat as gospel is based on bad science, misinterpreted studies and questionable behaviour by the food industry. Don’t believe me? Read on to discover why it doesn’t matter if you skip breakfast, why exercise won’t do much to help you lose weight, and how all diet myths should be approached, quite literally, with a pinch of salt…
Myth: if you skip breakfast you will put on weight
‘Go to work on an egg!’, ‘Breakfast like a king!’ The idea that eating breakfast in the morning is the key to improving energy, concentration and mood throughout the day is a mantra ingrained in most of us from an early age.
But there is no idea given of what breakfast should entail, or when it should be eaten. However, there remains a belief that breakfast somehow ‘kickstarts’ the metabolism, or that skipping it means you’re hungrier later in the day and so overeat.
Despite a lack of evidence for these claims, they are presented as scientifically supported facts and clearly laid out in NHS guidelines prepared by government employees from Public Health England with input from the food industry.
A systematic review and analysis of breakfast-skipping studies was finally published in the British Medical Journal in 2019. It concluded that there was no evidence to support the claim that skipping meals makes you put on weight or adversely reduces your resting metabolic rate.
The data showed quite the opposite. There is evidence that fasting for longer than 12 hours can reduce insulin levels and help some people lose weight. So why have scientists got it so wrong in the past?
The worry that skipping breakfast could lead to overeating later in the day is theoretically justified: people who miss breakfast do both usually eat more lunch and slightly reduce their physical activity.
The body’s metabolism is also initiated by a process known as diet-induced thermogenesis, whereby the food itself generates some heat in the body and so, because of this, breakfast is often said to kickstart the metabolism.
There is evidence that fasting for longer than 12 hours can reduce insulin levels and help some people lose weight. So why have scientists got it so wrong in the past?
But these clever compensatory mechanisms, even when put together, are not nearly enough to make up for the weight-loss benefits entailed by the uneaten calories of a missed breakfast.
And let’s not forget that successful food industry conglomerates have a massive marketing budget and carry enormous clout with government officials, allowing them to influence public policy to the extent that verifiably false claims become sanctioned health advice.
By examining what multi-billion-dollar industries such as cereal manufacturing may stand to lose if more people begin skipping breakfast, it’s easy to see why breakfast myths are so widespread and persistent.
Myth: Fish is always a healthy option
We’re constantly inundated with messages telling us that fish is one of the healthiest foods. A low-calorie and high-protein food, with oily types rich in omega-3 fatty acids, which is supposedly good for the heart and brain. But our obsession with fish has been manipulated by the food and supplement companies, and the fish oil supplement industry is worth £23 billion.
Almost 20 per cent of Britons and ten per cent of Americans take a daily fish oil supplement, and the UK spends £2.8 billion a year on fish. But there’s bad news for fish fans: it isn’t as good as we’ve been led to believe.
A recent clinical trial of 259 pregnant women, followed up until their children were seven years old, found that fish oil supplementation during pregnancy did not lead to brighter children.
In fact, the evidence for omega-3 supplements being beneficial is non-existent.
Governments drum into us that we must cut down on our meat intake and instead eat two to three portions of fish a week if we wish to reduce the risk of disease. This is despite a complete lack of evidence.
While there’s nothing so far to show that fish does our health any harm, there is a clear downside to eating more of it. The oceans are struggling to meet the demand, not helped by increasing trends for cheaper farmed seafood, which is not only bad news for the environment but could be bad news for our health.
First, there is the routine use of high levels of antibiotics to help farmed fish grow and avoid infections caused by being kept close together.
There’s also an unlikely little critter that loves closely packed fish: the sea louse. These flesh-eating sea lice attach themselves to salmon and kill one in five of them, which costs the industry over £1 billion a year.
Alongside antibiotics, companies use hydrogen peroxide chemicals to control them but too much can harm the fish and will, eventually, cease to be effective.
Then there are the dangers that you’re consuming heavy metals such as lead and mercury that have accumulated in fish, or the possibility your seafood could be contaminated with microplastics.
By all means continue to enjoy fish, but pay more for better-quality, sustainable varieties – and don’t expect it to save your life.
Myth: We all need to reduce our salt intake
We’ve been warned about the dangers of salt for some time. For the past 20 years, governments have been encouraging us to reduce our intake and we are told that reducing it to below 6 grams (one and a quarter teaspoons) a day is the key to reducing blood pressure, strokes and heart disease.
But any health benefits from reducing salt intake pale into insignificance next to the proven benefits of blood-pressure medications.
Anti-salt lobby groups, diet professionals and governments want us to believe that any health improvements are the result of their public health interventions rather than drugs.
For most healthy people, the reduction in blood pressure as a result of salt reduction is surprisingly small and clinically trivial.
But even if there was compelling evidence that low salt intakes led to long-term reductions in blood pressure, this would be significant only if this reduced risks of cardiovascular disease and death.
In fact, studies of salt reduction have not found any reduced risk of heart attacks, strokes and death.
But it doesn’t end there. Another shock came recently when randomised clinical trials of patients with diabetes on low-salt diets reported that, rather than getting better, patients were consistently dying earlier.
There’s no doubt that very high salt intakes are linked to higher rates of hypertension and heart disease, but much of this can be explained by people eating too much salty ultra-processed food, which are also laced with an array of other chemicals that can affect our long-term health. If you avoid ultra-processed burgers, burritos, pizzas and crisps, you can still enjoy food without guilt, and we should take current guidelines with a large, and surprisingly healthy, pinch of salt.
Take the fat burn cracker test
Counting calories is not always useful because our bodies use them differently.
There is a simple experiment to determine how well-adapted your digestive system is to processing starch and therefore how well your body burns fat.
Eat a basic wheat cracker and time how long it takes for you to taste sweetness. When we tested twins, we asked them to do it three times and take the average as it is not always clear-cut.
We found that around a quarter of participants could detect the change to sugar within 30 seconds, suggesting that they are better adapted than most of us to burning starch – rather than storing it as fat – but we still don’t know how this affects us individually.
There is a simple experiment to determine how well-adapted your digestive system is to processing starch and therefore how well your body burns fat
Myth: Lots of Exercise will make you thin
‘Keep going!’ ‘Cycle harder!’ ‘The more calories you burn while in the orange heart-rate zone, the more fat you will burn and the more you can drink later.’
This was the mantra of the exercise class I attended in a gym a few years ago. We are all told that one of the main reasons we’ve all got fatter in the past 30 years is that we have become lazy and don’t exercise enough.
The exercise message is aimed at people of all ages, from children to pensioners – go to the gym, walk more, play sport, expend calories and the weight will melt away.
To help encourage us, wearable devices tell us when we have reached the magic 10,000 steps. Yet the 10,000-step goal – conveniently, a nice round number – was devised by a Japanese pedometer company before the 1964 Tokyo Olympics and has no scientific basis.
Activities such as weight-lifting, cycling or even just brisk walking are more likely to improve your health than just counting the number of steps you take. If your goal is to lose weight, exercise is not a magic formula and works only if you eat less in parallel.
Studying British twins, we found only a 2.2lb to 4.4lb lower weight in the twin who exercised regularly. This underscores the fact that most of our energy expenditure is determined by our genes. Like many diet myths, however, this is ingrained in the public consciousness.
We have always assumed that our ancestors spent their days running around hunting and that this kept them lean.
When I spent a week with the Hadza tribe in Tanzania, the last hunter-gatherers of East Africa, I was surprised. They seemed to be as lazy as us Westerners. They usually have a lie-in and go only as far as they need to get food, which, as most of the year it is plentiful, is not very far.
A team of researchers put activity trackers on the Hadza for 11 days. It was confirmed that they are sedentary for most of the time and on average don’t expend more calories on physical activity than Westerners.
The reason they are lean is due to their diverse high-fibre, berry and meat diet, not eating much, and avoiding snacks, rather than doing 10,000 steps per day.
The 12 simple rules you should follow
1. Eat diverse foods, mainly plants, without added chemicals
2. Question the science and don’t believe quick-fix single solutions
3. Don’t be fooled by labels or marketing
4. Understand your own body and realise that there is no such thing as average
5. Diversify! Don’t get stuck in a food rut
6. Experiment with meal timings and skipping meals
7. Use real food, not supplements
8. Avoid ultra-processed foods containing more than ten ingredients
9. Eat foods to improve gut microbe diversity such as full-fat natural yogurt, kefir, kimchi, sauerkraut and good quality cheese
10. Reduce regular blood sugar spikes by avoiding sugary drinks and snacks and refined carbohydrates such as white bread
11. Reduce meat and fish consumption and check its sustainability
12. Educate yourself and the next generation in the importance of real food
Myth: Adopt a vegan diet to stay healthy
The number of vegans in the UK almost quadrupled between 2014 and 2019, with one in eight Britons describing themselves as vegan or vegetarian. Meanwhile, a third of British consumers now have meat-free days and regularly buy plant-based milk alternatives. But is a vegan diet really as healthy as we are led to believe?
Many people claim they feel better and have more energy on a plant-based diet. Some will benefit because they begin to think more carefully about what they are eating, choose healthier foods and avoid random snacking.
However, veganism doesn’t mean eating limp lettuce leaves, tasteless tofu and a few bland beans. Nowadays there’s vegan mac ‘n’ cheese, ‘bleeding’ beetroot burgers and vegan fried chicken. There are also plant-based versions of favourite meats, cheeses, desserts and ice creams, pumped full of chemicals, sugar and saturated fats.
Whether your sausage roll is made from a pig or Quorn, or your burger from beef or soy, they’re all highly processed and high in calories, saturated fat and salt.
What’s more, vegan and vegetarian foods are marketed as healthier than they in fact are, and some, such as vegan fish fingers, contain up to 40 artificial ingredients.
While the craze for plant-based milks has taken off, there’s no evidence they’re any healthier than cow’s milk. Many are devoid of key nutrients such as calcium, iron and B12 found in dairy, and can contain excessive levels of chemicals and additives.
A bigger concern is the rise in veganism among children. Studies have shown that vegan children are often smaller and have low levels of nutrients such as riboflavin and B12. In extreme cases these deficiencies have led to high-profile deaths.
So, veganism per se is not necessarily healthy. Most of the benefit is probably just through eating a greater variety of plants and fibre, which can be achieved by people consuming small amounts of meat and dairy. Don’t feel pressured into buying these plant-based alternatives, which are often full of additives, sugar and fat.
© Tim Spector, 2020
Spoon-Fed: Why Almost Everything We’ve Been Told About Food Is Wrong, by Tim Spector, is published by Jonathan Cape on August 27, priced £12.99