For more than 30 years I’ve been a GP, and though I hope I have been a good one, I owe many of my overweight patients an apology.
Until recently, I trotted out the standard weight-loss advice: eat a low-fat diet, pile your plate with starchy carbs and cut back on fat.
You must not, I told them, allow yourself to get hungry — and never, ever go on a rapid weight-loss diet as you’ll simply put the weight back on, and more.
Now, in a new three–part series for Channel 4 that I’m co-presenting with my lovely husband and TV doctor, Michael Mosley, we’re helping people lose weight by doing almost exactly the opposite.
Our group of obese or overweight volunteers all want to shed the pounds put on during lockdown — and in the series we show them trying to do it, by starting on a rapid weight-loss diet for three weeks.
Dr Clare Bailey and her husband Dr Michael Mosley will help people lose weight in their new three–part series for Channel 4
So why my change of heart? It started when Michael discovered eight years ago that he had type 2 diabetes. He wasn’t particularly overweight, but he did have a bit too much fat stored around his middle (visceral fat, the kind that’s linked to diseases including type 2 diabetes).
He managed to lose nearly 10kg (22lb) in eight weeks and get his blood sugar levels back to normal by going on what he called a 5:2 diet, cutting right down on his calories for two days a week and eating normally on the other days. He also stopped snoring the house down, which I was particularly grateful for.
Not surprisingly, I became very interested in diet and the impact of food on our bodies and brains.
Like most GPs, until that point I would give the standard advice and refer patients to a weight-loss programme, if available. When that failed, I would put those with type 2 diabetes on medication, which they rarely came off. In fact, most continued to gain weight, needed more medication, with many ending up injecting insulin.
Then, in 2014, Michael saw Roy Taylor, a professor of medicine and world expert in diabetes from Newcastle University, who explained that by losing all that weight, he’d drained the fat from his liver and pancreas and reversed his diabetes.
Roy’s studies showed that going on an 800-calorie daily diet of meal replacement shakes for eight weeks, before returning to more normal eating, led to weight loss of up to 14kg (30lb) and could get most patients off type 2 diabetes medication.
So I began asking my overweight patients if they would like to try this approach. I lent them copies of my 800-calorie recipe books, based on a low-carb, Mediterranean-style diet (high in protein and fibre, and rich in nutrients).
Most were surprised how easy it was to do and were delighted how quickly they lost weight and saw improvements in their blood sugar levels, blood pressure and cholesterol.
Enthused by this, three years ago I met up with Professor Susan Jebb, a world authority on weight loss from the University of Oxford.
She agreed to run a study to test a low-carb, 800-calorie approach with real food. This meant eggs for breakfast rather than toast or cornflakes, and having a salad with fish or chicken for lunch instead of a sandwich.
This became the Diamond study, a small(ish) study involving 33 overweight or obese patients with type 2 diabetes, with nurses in GP surgeries offering advice and monitoring the participants’ progress.
The couple will help a group of obese or overweight volunteers who want to shed the pounds put on during lockdown. Stock image)
What we showed — the results were recently published in the Journal of Obesity, Diabetes and Metabolism — was that those sticking to a diet of 800 calories a day for two months, followed by a four-week weight-maintenance period, lost almost five times more weight than those following standard advice.
And unlike this group, they also saw improvements in blood sugar levels and blood pressure.
We were thrilled, but despite the low cost of this approach, and the huge potential health benefits, we’ve not yet been able to get funding to do a larger and longer study, which would add to the body of evidence and encourage people to adopt this approach.
That’s why I was keen to be involved in this new series and promote the research.
It really is time to change attitudes to rapid weight-loss diets — not least as losing weight and getting blood sugar levels down will improve immunity and reduce your risk of complications should you be unlucky enough to get Covid-19.
Clearly a rapid weight-loss, low-carb diet will not suit everyone, and those on certain medications and with medical conditions should discuss any diet with their GP first.
But the belief that rapid weight-loss diets don’t work is misplaced. It’s not the only one, and these unhelpful myths mean those who might benefit miss out. So here are my seven top weight-loss myths debunked.
1. RAPID WEIGHT LOSS DOESN’T WORK
There is now good evidence that rapid weight loss, when done properly for a short period of time, followed by a return to healthy eating, can be safe
Although many people are convinced that rapid weight loss diets are dangerous and lead to weight gain, there’s now very good evidence that when they are done properly — for a short period of time, followed by a return to healthy eating — they can be safe and incredibly effective.
For example, in a large controlled trial, run by Professor Taylor and Mike Lean, a professor of human nutrition at Glasgow University, 298 patients were allocated to either an 800-calorie-a-day diet for a couple of months, or to a control group, who received standard NHS care.
Two years later, those who started on 800 calories have maintained an average weight loss of 7.5kg (15lb), nearly four times more than those in the control group. They’re also now on half the medication of the control group. And they are much happier, too.
2. FAST WEIGHT LOSS SLOWS METABOLISM
There is a widespread fear that if you cut calories, you will go into ‘starvation mode’, and your metabolic rate — the rate at which you burn calories at rest — will crash and you won’t lose any weight.
This belief is based on the Minnesota starvation experiment, during World War II, when young slim volunteers were put on a diet consisting mainly of potatoes and turnips for six months. It didn’t end well, with many of the volunteers gorging when allowed to.
More recent studies show that cutting calories does cause your metabolic rate to slow a bit, mainly because you are carrying less weight around, but it isn’t dependent on the rate at which you lose the weight.
One of the best ways to speed up your metabolic rate is to do more exercise, particularly muscle-building exercises such as squats and press-ups (muscles burn calories, even when you’re asleep).
3. YOUR BODY CAN ONLY RUN ON SUGAR
Another common misconception is that we need sweet and starchy foods to provide us with energy. But if you’re overweight, you have a store of energy in the form of fat.
Your body treats fat like money in the bank, set aside for a rainy day. To dig into those fat stores and lose weight, you first need to run down your sugar supplies.
When your body goes from using sugar (which is what carbs are broken down into) to burning fat for fuel, you really start to lose weight. Many people go into fat burning (known as ketosis) within a few days on an 800-calorie diet.
My patients tell me that when they go into ketosis, this suppresses their appetite and makes them feel more energetic.
4. FAT IS BAD FOR YOU
There are plenty of ‘good’ fats such as those found in oily fish, olive oil or nuts, which have been shown to lower your risk of stroke and heart disease
While some fats are definitely bad for you (e.g. those in highly processed junk food) there are also plenty of ‘good’ fats such as those found in oily fish, olive oil or nuts, which have been shown to lower your risk of stroke and heart disease (they’re also broken down slowly, leaving you feeling full for longer).
In our house, we also have full-fat milk and full-fat live yoghurt (the latter adds health-promoting ‘good’ bacteria).
5. EXERCISE IS THE WAY TO LOSE WEIGHT
Exercise is great for cardiovascular health, mood, improving strength and sleep and boosting metabolic rate. But it’s a lousy way to lose weight. You’d need to run 36 miles to burn off a single pound of fat — and two-and-a-half miles for just a small bar of chocolate.
6. SNACKING IS VITAL TO AVOID HUNGER
Some dietitians still tell patients they should never get hungry, because if they do they’ll make bad food choices. That’s why we were told always to eat breakfast, have a snack mid-morning, mid-afternoon and before bed.
Yet when in 2014 researchers from the Clinical and Experimental Medicine Hospital in Prague fed two groups of patients meals with the same number of calories (1,700) but taken as either two or six meals a day, they showed just how bad that advice was.
The two-meals-a-day group lost, on average, 1.4kg (3lb) more than the constant eaters, and 1.5in more from around their waists over six weeks. The six-meals-a-day group also felt hungrier.
7. YOU CAN ONLY LOSE WEIGHT IF YOU HAVE STRONG WILLPOWER
Sometimes you have it, sometimes you don’t. So best to assume it doesn’t exist and plan to make it easier to resist temptation
Willpower is fickle. Sometimes you have it, sometimes you don’t. So best to assume it doesn’t exist and plan to make it easier to resist temptation.
So don’t go shopping when you’re hungry and put any likely temptations out of sight (I have to hide milk chocolate from Michael) — or, even better, don’t have such treats in the house!
Lose A Stone In 21 Days With Michael Mosley will be shown tomorrow on Channel 4 at 9pm.