Embarking on regimes which make you feel like a failure is just discouraging but a good basic rule is that what’s good for the heart is generally good for the brain. That means eating oodles of vegetables and fruit, plenty of fibre and avoiding processed foods as much as possible. It also means trying to eat in moderation and burn more calories than we consume.
The problem is that these messages aren’t landing. The Lancet Commission forecasts that increasing mid-life rates of obesity will lead to a 19 per cent increase in dementia in China and a 9 per cent increase in the US by 2030.29 That is tragic.
We Are Our Own Worst Enemies
Professor Andrea Maier, geriatrician at the University of Melbourne, Australia, has put it wonderfully bluntly: ‘We are very lazy, we are a very lazy species and we just have to overcome that.’ She states there are three main reasons why two people can look very different from each other at the age of 50. These are: first, their levels of physical activity; second, whether they smoke; and third, their diet.
Smoking rates are falling, of course. But even as we are vanquishing smoking, obesity is rising to take its place.
My mother could have drawn the chart below. A chain smoker from the age of 14, she took up cigarettes as an act of rebellion at her American convent school. She didn’t give up until she was 70, when her arteries got so clogged that she had a mini stroke. It was a dreadful struggle for her to give up cigarettes, even with the help of nicotine patches. She immediately began gorging on chocolate, put on two stone and lost the perfect figure of which she’d been so proud. She became diabetic and later developed vascular dementia. I couldn’t help thinking, after her final, fatal heart attack, that she might have been happier staying on the fags. She existed almost entirely on ready meals after she left my father – she said she never wanted to cook for anyone again. And she never took any exercise: for most of her generation it was simply not on their horizon.
To start with, my mother didn’t really notice what was happening. As it becomes normal to be fat, people who see others the same size as them may not even notice. The psychological tendency to ‘anchor’ to those around us is very strong: in one study of 3,000 parents, a third did not even recognise that their own children were obese or overweight.30
A vociferous lobby insists that obesity is genetic, but my mother came from a line of beanpoles. Look at any map showing the spread of the disease. It’s simply not possible that an epidemic like this could be genetic, eating its way through every US state, English counties and regions of Mexico. Genes do ‘load the gun’, making some people struggle harder to resist food and to manage their weight. But it is environment – diet and sedentary lifestyles – which ‘pulls the trigger’.
One in four adults in the UK, and four in ten in the US, are now clinically obese. Britons have the highest average body mass index in Western Europe.31 That’s because we are eating more calories than we burn. The average American’s total calorie intake grew from 2,109 calories in 1970 to 2,568 calories in 201032 – the equivalent of eating an extra steak sandwich every day. Few people are exercising enough to compensate, especially as they drive more.
Some experts now think diet is actually less important than car ownership. In 1949, 34 per cent of miles in the UK travelled using a mechanical mode were made by bicycle; today, only 1–2 per cent are.33 There is a stunning correlation between driving more miles and getting fatter – with a six-year time lag.34
Obesity Is Making People Old Before Their Time
Extreme obesity can knock eight years off your life, according to one Canadian study. But even being overweight has a clear impact on how we age. One study found that obese people had substantially less white matter in their brains than leaner people. While our brains naturally shrink with age, the brains of the obese people were found to have a comparable white matter volume to a lean person 10 years their senior.35 The impact on cognitive function is not known, but it’s unlikely to be good.
Obesity is the main cause of type 2 diabetes, which is most prevalent in older people. The number of Brits with type 2 diabetes has doubled in 20 years36 and it now accounts for almost 9 per cent of the annual NHS budget. A third of Americans over 65 now have type 2 diabetes.37 The consequences can be really nasty: blurred vision, sores which won’t heal, even toe, foot and leg amputations.
Type 2 diabetes develops when our bodies consume so many carbohydrates that the pancreas ceases to release the right amounts of the hormone insulin into the blood, to regulate the glucose that gives us energy. Our systems are overwhelmed and they fail.
People who head into their sixties obese are storing up real trouble in Extra Time. Doctors are wary of interfering, because they feel that what we eat is a ‘lifestyle choice’. Personally, I’m not so sure how much of a choice it is. Public health agencies have spent decades exhorting people to lose weight with almost no effect. I have become convinced that one reason we find it so hard to lose weight is that junk food – especially sugar – is addictive.
The Story of the Sugar Tax
When I served on the board of the Care Quality Commission, the national regulator for hospitals, the scourge of obesity was everywhere. Hospitals were having to reinforce beds for super-sized patients. Doctors were refusing knee replacements to people who were so overweight they feared the replacements would buckle under the strain. Some of those people became less active because their joints hurt and so gained even more weight. It was a terrible vicious cycle.
Around the same time I watched a talk by the American paediatric endocrinologist Professor Robert Lustig.38 He argues that sugar is the main cause of obesity, because sugar is as addictive as nicotine and switches on the same hormonal pathways which reward behaviour. Low blood sugar affects mood, concentration and the ability to inhibit impulse. Eating or drinking something sugary reverses the effect, but if the pattern is repeated for long enough, it results in insulin resistance, type 2 diabetes, heart disease and obesity. Professor Lustig believes that it is not possible for most people to quit through willpower because that has been eroded by the cycle of craving.
My mother’s switch from nicotine to sugar made Lustig’s narrative especially compelling for me: she simply replaced one addiction with another. And it chimed with my own experience. Battling exhaustion after my third child, and sitting opposite a fellow columnist who practically mainlined Coca-Cola, I fell into the habit of needing a Coke and chocolate bar before every deadline. Since I was filing copy almost every day, as a Times leader writer, my consumption of sugar was considerable. And pretty soon the chocolate bar was no longer a single small, elegant Green & Black’s, but a string of Yorkie bars.
This kind of ‘mindless eating’ has been brought to life, hilariously and poignantly, in experiments by Brian Wansink of Cornell University. In one, he gave stale popcorn to two groups of cinemagoers.39 One group got big buckets, the other got giant buckets so large that researchers assumed no one would finish them. When the movie ended, the people with giant buckets had scoured them clean – they’d consumed 50 per cent more popcorn than the others. When told this, most were astonished.
For decades, we were warned off saturated fat. A profitable industry grew up selling ‘low-fat’ processed foods. But these are a con. To make them tasty, manufacturers stuff them with carbohydrates and sugar. These create spikes in blood-sugar levels, which lead to cravings when blood sugar falls, along with the brain’s chemical messenger, dopamine. Dopamine gives pleasure, but also regulates our self-control. So Big Food offering low-fat cakes is the equivalent of Big Tobacco offering low-tar cigarettes: they make us feel better about ourselves, while keeping us hooked.
I hope that doesn’t sound hysterical. In 2015, there was a mortifying moment when I was called a ‘health fascist’ by one of the prime minister’s other advisers. We had