Zoe Harcombe spent a decade piecing together the answer to the question “Why do we overeat when all we want is to be slim?”.
Through experience and research she discovered three very common conditions that cause insatiable food cravings.
You may have heard of them, you may know that you have one or more of them, but you are unlikely to know how they have turned you into a food addict:
Candida: is a yeast that lives in all of us, but it can easily multiply out of control, creating many nasty symptoms – from bloating and fatigue to irritable bowel syndrome and mood swings.
Foods that encourage Candida growth are the ones you crave – bread, fruit, pickled foods, cereal: basically any processed carbohydrates.
The more you give in to the cravings, the more you feed this condition – and the more of a food addict you become.
Food Intolerance: occurs when you have the same foods every day and you literally become intolerant to them, but you crave them to avoid the withdrawal symptoms that occur when you don’t consume them.
The most common intolerances are to wheat and dairy foods – in that order.
We have cereal (wheat) and milk (dairy) for breakfast, sandwiches (wheat) and lattés (dairy) for lunch, pasta for dinner with maybe yogurt for dessert. No wonder wheat and dairy are our biggest problems.
Hypoglycaemia: is suffered by most people, most days at around 11 a.m. and 4 p.m. It’s that “can’t concentrate/must have some food” kind of feeling and it causes intense cravings for carbs – especially sweets and chocolate etc.
When blood glucose levels dip below normal, your body will do whatever it can to get you to eat something – to get the level back up.
When you get that 11 a.m./4 p.m. feeling – you reach for a muffin, or a bar of chocolate. Yet this gives you way more sugar than you need, so you may release too much insulin coping with this unrecognized modern “food” and then your blood sugar level dips again.
This is why many people find that they can’t stop eating once they start – you never manage to get stable blood sugar levels throughout the day.
Two books were to provide the key remaining bits of the puzzle: New Low Blood Sugar And You by Carlton Fredericks and Candida Albicans: Could yeast be your problem? by Leon Chaitow.
The final piece in the jigsaw was a show-stopper. There are many and varied causes of these three conditions, but they all have one cause in common – calorie counting.
Trying to eat less drives people down the route of eating more of the foods that make these problems worse.
Fruit, muesli bars, cereal, low-fat/low-calorie products – things that you think are healthy – are feeding these conditions beautifully. So, start a diet and you will end up a food addict – the pathway is as clear as that.
Zoë Harcombe, author of new book claiming to end food addiction, reveals how she finally won the battle of the bulge
And so Phase One of The Harcombe Diet was born. It only needed to be five days long – driven by food intolerance – as any food to which you are intolerant has passed through you in this time.
The core foods of meat, fish, eggs, vegetables, salads, brown rice and Natural Live Yoghurt (the latter helps to fight candida) emerged as the “super foods” that would fight these nasty ailments.
Candida and food intolerance both cause serious water retention, and pounds can be dropped in the first few days – shrinking you by one dress size in the process.
More typically, people lose 7 lb in five days – but without going hungry or counting a single calorie. In fact, it is vital that you eat plenty – trying to eat less will make you overeat faster than you can say “I’m starving!”.
Zoe Harcombe said: “Within days, not even weeks, of working out Phase One, I had reached my natural weight of eight stone and I have been there ever since. I could never have imagined that I could eat as much as I do and stay at my perfect weight so easily – not least while eating a 100g bar of 85 per cent dark chocolate every day!
“To say this has changed my life is an understatement. I wasted a decade of my life obsessed with food but terrified of it at the same time. I would turn down social invitations because I felt fat and then sit at home and stuff my face instead.
“I started every day thinking <<today will be different>>, but it never was because I simply did not know why I could not resist the urge to eat – not everything, but quite particular things: biscuits, chocolate, cakes, crisps…you know the foods I mean!
“I hated myself and beat myself up for my assumed lack of willpower, but it wasn’t my fault. I was an addict, and only when I understood the cause of the addiction could I overcome the causal conditions and get back in control of food.”
Freedom from any addiction is wonderful. Freedom from food addiction is the best thing of all, as we have to eat – we just need to be able to control what we eat and not have what we eat control us.
And so Zoe Harcombe wrote Why Do You Overeat? When All You Want Is To Be Slim.
She said: “I put my email address in the first edition of the first book – thinking that about 20 people would read it.
“Hundreds of emails later I realized that people were losing several pounds in Phase One, then going on to lose several more in Phase Two – and still keeping this weight off.” Some meal ideas on the Harcombe diet:
In a fascinating new book, Robert Lustig, a professor of clinical pediatrics at the University of California, expounds a whole new scientific theory about eating too much.
Robert Lustig argues that the urge to overeat and lounge around doing nothing is not a sign of weakness.
It is, he says, a hormonal issue, triggered by eating too much sugar.
He points the finger of blame at the hormone leptin, which acts like an appetite thermostat.
As one of two “hunger hormones” in the body, leptin works to decrease the appetite (its partner, ghrelin, increases appetite).
When you have had enough to eat, your fat cells release leptin, which effectively dulls the appetite by instructing the brain that it’s time to stop eating.
Professor Robert Lustig warns that our sweet tooth is sending this process haywire.
SUGAR TRICKS YOUR BRAIN
For many years scientists thought obesity could be caused by a shortage of leptin – thinking that without adequate levels, overweight people simply never received the message that they were full.
But more recent studies have shown that obese people have plenty of leptin (in fact, the fatter you are, the more of it you appear to have), but are more likely to be “leptin-resistant”.
This means the cells in the brain that should register leptin no longer “read” the signals saying the body is full, but instead assume it is starving – no matter how much food you continue to eat.
In panic, the brain pumps out instructions to increase energy storage – instigating powerful cravings for high-fat, high-sugar foods because these are the easiest and most immediate forms of energy – and conserve energy usage, by dampening any urge to get up off the sofa and go for a run.
The food cravings are made even more intense – and impossible to resist – because leptin is supposed to dampen the feeling of pleasure and enjoyment you get from food by suppressing the release of the brain chemical dopamine, helping to decrease appetite.
But if you are leptin-resistant, food never stops tasting delicious, no matter how much of it you eat.
This, says Prof. Robert Lustig, is why many overweight people find it so hard to stop eating, and why diets so often fail.
THE HUNGER HORMONE
Scientists have been struggling to work out what causes leptin resistance.
But now Prof. Robert Lustig and his team have been able to show – in repeated studies on humans – that too much sugar in the diet is to blame.
High sugar diets lead to spikes in the hormone.
This is needed to clear sugar out of the blood and into storage as fat.
But repeated insulin spikes, due to a high sugar diet, can lead to a condition called “insulin resistance” (when the cells have been so bombarded by insulin they no longer respond to it).
Prof. Robert Lustig believes insulin resistance triggers leptin resistance, and, crucially, he has discovered that by reducing insulin levels it is possible to improve “leptin signalling” (the brain’s ability to read leptin), stop cravings, put the brakes on food consumption – and trigger weight loss.
In his new book Fat Chance, Professor Lustig explains that leptin resistance – and sugar – is at the root of the obesity epidemic.
He believes 1.5 billion overweight or obese people in the world suffer from this condition – and is convinced that the problem can be tackled by targeting insulin.
In his studies, many participants took insulin-lowering drugs, but the professor says similar results can be achieved by a few small lifestyle changes – notably reducing sugar in your diet.
The professor has a heavyweight background in endocrinology (the study of hormones), as both a medical doctor and academic.
He used organized trials to study the role the brain plays in governing appetite and activity levels and found that patients who had damage to the hypothalamus (the area of the brain that controls energy levels) could not lose weight, but somehow gained weight even when restricted to a near-starving 500 calories a day.
Robert Lustig realized that a similar process could be happening with obese adults and set out to investigate a potential solution.
His studies revealed that the roles of leptin and insulin are intertwined, and bind to cells in the same area of the brain – the hypothalamus.
The real reason you eat too much
SWEET FOOD LEAVES YOU WANTING MORE
A high sugar diet can trigger leptin resistance even if you are just slightly overweight. This is because sugar triggers a spike in insulin.
While leptin activates biochemical reactions that send “satiety signals” to the brain, insulin can very effectively block these signals, resulting in no satiety, no sense of fullness, and uncontrolled eating of high fat, high sugar foods.
This is leptin resistance, and leaves the brain “blind” to leptin signals, so it still thinks we’re hungry.
Even worse, in healthy people, one of the things leptin should do is to tell the brain to reduce insulin production. It does this by dulling appetite and thus reducing food intake (so cutting the body’s need to produce yet more insulin to deal with the food).
But if you have too much insulin and you are leptin-resistant this doesn’t happen, and insulin levels rise ever higher, creating a vicious cycle.
Robert Lustig believes that our high sugar diets cause continually stimulated insulin production.
He says the insidious creep of insulin resistance means that our bodies now produce double the insulin for every teaspoon of sugar consumed compared to 30 years ago.
He says insulin resistance is now so widespread, it affects the majority of overweight people and even as many as 40% of those who are normal weight (if they eat too much sugar and refined carbohydrates like white flour, bread, pasta and rice).
And leptin resistance becomes more of a problem with increasing body size. “Plump people might have a little leptin resistance, but the morbidly obese will have a lot,” he says.
WHY ONE CHOCOLATE IS NEVER ENOUGH
The sweet, processed food that makes up so much of the modern diet (much of it disguised as ‘low fat’ and therefore healthy) has addictive qualities – particularly for those caught up with leptin resistance.
When we eat food, the brain chemical dopamine is released, creating a feeling of pleasure and reward, explains Prof. Robert Lustig.
Then leptin kicks in to suppress the release of dopamine, so that we get less reward, and therefore we stop eating.
But, he adds, if you’re leptin-resistant, the dopamine won’t be suppressed properly, and it remains at high levels in the brain, and “floods” the brain cells.
After many meals (over a period of about three weeks) brain cells may start to become “tolerant” to these persistently high levels of dopamine.
They build up resistance, meaning that higher and higher amounts of dopamine are needed to trigger a reward signal.
As a result, you may feel compelled to eat greater quantities to achieve the same sense of satisfaction. This can swiftly turn into sugar addiction.
Insulin also works to clear dopamine from the brain, gradually blunting the reward felt for further food.
But if you’re insulin-resistant too, the brakes won’t work, and the reward impetus continues unabated.
This, Prof. Robert Lustig believes, explains why many people can want, and apparently enjoy, never-ending quantities of food even when energy stores were long ago full – for example over the Christmas period.
He fears insulin resistance (and therefore leptin resistance) may also start in the womb, and that exposure to high sugar diets – via the mother – may trigger genetic changes that increase a baby’s risk of insulin and leptin resistance in later life.
But he adds: “At the end of the day, it is what you eat (and of course, how much of it) that puts the final nail in the coffin.”
A BIG FAT LIE
Conventional wisdom and government policy still blame dietary fat for our ever-rising obesity levels (and horrific heart disease statistics).
However, Prof. Robert Lustig is part of the band of obesity specialists who question the validity of the hugely influential research conducted in the Fifties, which identified dietary fat as the trigger for weight gain and heart disease.
The seminal Seven Countries study by U.S. epidemiologist Ancel Keys in the Eighties demonized fat, triggering a massive change in food manufacture.
In an effort to make low fat food more palatable, many manufacturers raised the carbohydrate level, adding quantities of sugar to almost everything (both sweet and savoury).
For instance, a small pot of low fat yoghurt can contain as much as four teaspoons of sugar, and even wholemeal bread hides two teaspoons per loaf.
Gradually tastes and eating habits have changed, Robert Lustig says, resulting in growing populations worldwide inadvertently hooked on easy-to-eat high sugar foods.
As he puts it: “The obesity epidemic was born in the aftermath of this seemingly logical and well-meaning, yet tragically flawed understanding of our biochemistry.”
Mercifully, it is not all doom and gloom.
“Obesity is a hormonal problem and hormones are alterable,” says Prof. Robert Lustig.
He recommends simple steps that can lower your leptin levels.
These include reducing sugar in every recipe by a third, increasing your fibre intake, and taking just 15 minutes of activity every day.
Scientific evidence increasingly points to a far deeper problem that confronts dieters: cutting out calories changes your metabolism and brain, so your body hoards fat and your mind magnifies food cravings into an obsession.
Slimmers have often feared this was somehow true, but now science confirms this cruel fact of nature. New research shows dieting raises levels of hormones that stimulate appetite – and lowers levels of hormones that suppress it.
Meanwhile, brain scans reveal that weight loss makes it harder for us to exercise self-control and resist tempting food. Worse still, the more people diet, the stronger these effects can become, leaving some almost doomed to being overweight as a result of their attempts to become slim.
And as research lays bare the dangers of yo-yoing weight, some experts argue it would be better not to diet at all.
Researchers, including Joseph Proietto, a professor of medicine at the University of Melbourne, have uncovered one of the main possible reasons. Two years ago, his team recruited 50 obese men and women, and coached them through eight weeks of an extreme 500-to-550-calories-a-day diet (a quarter of the normal intake for women).
At the end, the dieters lost an average of 30 lb. Joseph Proietto’s team then spent a year giving them counseling support to stick to healthy eating habits. But during this time, the dieters regained an average of 11 lb. They also reported feeling far hungrier and more preoccupied with food than before losing weight.
As the researchers reported in The New England Journal of Medicine, the volunteers’ hormones were working overtime, making them react as though they were starving and in need of weight-gain. Their levels of an appetite-stimulating hormone, ghrelin, were about 20% higher than at the start of the study. Meanwhile their levels of an appetite suppressing hormone, peptide YY, were unusually low.
Furthermore, levels of leptin, a hormone that suppresses hunger and raises the metabolic rate, also remained lower than expected.
Joseph Proietto describes this effect as “a co-ordinated defense mechanism with multiple components all directed toward making us put on weight”. In other words, the body had launched a backlash against dieting.
The team’s landmark study reinforces a belief among biologists that the human body has been shaped by millennia of evolution to survive long periods of starvation.
Cutting out calories changes your metabolism and brain, so your body hoards fat and your mind magnifies food cravings into an obsession
The human frame contains around ten times more fat-storing cells in relation to its body weight than most animals (polar bears, which have to endure long stretches when prey is unavailable, are similarly fat-rich).
Our calorie-hoarding frames have strong mechanisms to stop weight loss, but weak systems for preventing weight gain. If you manage to lose 10% of your weight, your body thinks there’s an emergency. So it burns less fuel by slowing your metabolism.
The body learns to function on fewer calories, resetting your metabolism. The problem is if you then stop dieting and start eating more again, those extra calories are stored as fat.
This effect kicks in after around eight weeks of dieting – and can last for years. Studies by Columbia University show this metabolic slowdown can mean that just to maintain a stable weight, people must eat around 400 fewer calories a day post-diet than before dieting.
Why would this be so? Muscle samples taken before and after weight loss show that once a person drops weight, the fibres may change to become more fuel-efficient – burning up to a quarter fewer calories during exercise than those of a person at the same weight naturally.
How long this state lasts isn’t known, though some research suggests it might be up to six years.
It’s also thought the brain changes in the way it reacts to food. This wilts our willpower, according to Michael Rosenbaum, a researcher at Columbia University Medical Centre who studies the body’s response to weight loss.
“After you’ve lost weight, there’s an increase in the emotional response to food,” he says, adding that there is also “a decrease in the activity of brain systems that might be more involved in restraint”.
In 2010, Michael Rosenbaum and his colleague, Joy Hirsch, a neuroscientist at Columbia University Medical Centre, scanned the brains of people before and after weight loss while they looked at objects such as grapes, chocolate, broccoli and mobile phones.
After losing weight, the scans showed a greater response in the areas associated with reward and a lower response in those associated with self-control.
And last year, scientists at the Albert Einstein College of Medicine in New York discovered that when starved of food, brain cells actually consume each other. This causes the release of fats, which in turn results in higher levels of a powerful brain chemical that stimulates appetite, the journal Cell Metabolism reports. All bad news for dieters, as going without food could make them even hungrier.
All of this helps to explain why an analysis of 31 long-term clinical studies found that diets don’t work in the long run. Within five years about two-thirds of dieters put back the weight – and more. The researchers from the University of California found that dieting works in the short term, with slimmers losing up to 10% of their weight on any number of diets in the first six months of any regimen. But after this, the weight returns, and often more is added, says their report in the journal American Psychologist.
The analysis concluded that most volunteers would have been better off not dieting. Their weight would be pretty much the same and their bodies would not have wear and tear from yo-yoing.
This backfire effect is worst among teenagers: people who start habitually dieting young tend to be significantly heavier after five years than teens who never dieted. This mix of biology and psychology translates into a sobering reality: once we become overweight, most of us will probably remain that way.
Certainly, we should all be worried about what dieting does to our health. Restricting calories may increase the risk of heart disease, diabetes and cancer, according to a study from 2010 in the journal Psychosomatic Medicine.
Ultimately, of course, we should be more wary of piling on the pounds, than relying on diets to reverse the damage.