Why you need to sleep more to eat less: Are you reaching for the biscuits every afternoon? Do you think you may be hooked on chocolate? You’re probably not getting enough kip …

Anyone whose sleep has been affected by the recent lockdowns will be well aware of the impact that poor sleep has on memory, mood and concentration.

But you may not realise that insufficient or poor-quality sleep is also very bad news for your waistline, your blood sugar levels and your sex drive.

Stress and tiredness trigger fierce cravings for fatty, sugary high-calorie foods, such as chocolate and biscuits. 

Stress and lack of sleep also change the balance of hormones in your body, making it much more likely that your blood sugar levels stay high and that excess fat will be laid down around your abdomen.

All this week I have been highlighting new studies which point to the dangers faced by millions of people in the UK who have found themselves gaining weight during lockdown.

Recent shocking figures from Diabetes UK revealed that the number of people with diabetes has doubled in the past 15 years.

Anyone whose sleep has been affected by the recent lockdowns will be well aware of the impact that poor sleep has on memory, mood and concentration. But you may not realise that insufficient or poor-quality sleep is also very bad news for your waistline. Pictured: Dr Michael Mosley and his wife Dr Clare Bailey

The number with prediabetes, where your blood sugars are raised but not yet in the diabetic range, have also soared, to nearly 14 million. And according to the NHS, one in three of us, unknowingly, has early signs of fatty liver disease, caused by excess weight. These are warning signs that we should all heed.

If you’ve got type 2 diabetes, pre-diabetes or just high blood sugar, the message is clear: do something about it. If you’ve been wondering whether you might have blood sugar problems, I recommend you ask your GP if you need to be tested. You can also buy a blood sugar monitor from a chemist, or online.

People who have a family history of diabetes or hypertension are most at risk, but if your waistline has been steadily expanding and you are considerably heavier than you were in your 20s, that is another clear sign your blood sugars could be raised.

Things are likely to get worse unless you act. Now.

QUALITY SLEEP AND LOW STRESS ARE KEY

There are lots of studies which show that poor-quality sleep is really bad for our health. It leads directly to weight gain and increases your risk of type 2 diabetes.

I’ve worked hard to try to improve my sleep quality since insomnia crept up on me in my 40s, after a decade of juggling a demanding career with the inevitably broken nights of bringing up four young children.

It contributed to the steady weight gain which resulted in me being diagnosed with type 2 diabetes at 55. At that time, in 2012, I weighed 14 st and had a 36 in waist (or, to be honest, more like 37 in).

I put myself on the 5:2 diet, lost 19lb and reversed my diabetes diagnosis, but I am constantly watchful in case my weight starts to creep up again, and that means taking steps to ensure I manage my stress levels and get as much good quality sleep as I can.

In the name of science, I’ve spent many nights in sleep labs with electrodes attached to my head and body. For one of my TV shows I took part in a sleep deprivation experiment with a group of volunteers. It wasn’t that bad, we simply went to bed three hours later than normal for two nights. Nonetheless, we all noticed a dramatic increase in our hunger.

IS POOR SLEEP MAKING YOU FAT? 

If you answer ‘yes’ to three or more of the following questions, it is likely you have a sleep problem and it could be affecting your health.

1. When your head hits the pillow, do you find it hard to fall asleep?

2. Do you wake up during the night and then find it hard to get back to sleep?

3. Do you wake up earlier than you want to and find it hard to get back to sleep?

4. When you wake up, do you feel exhausted?

5. Do you feel tired and irritable during the day?

6. Do you find it difficult to concentrate during the day because you’re feeling tired?

7. Do you get mad cravings for carbs (biscuits, cakes or something sweet) during the day?

8. Do you nod off while watching TV, while in the cinema or in a public place?

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One of the other volunteers developed a desperate craving for custard cream biscuits and ate a packet before breakfast — something he’d never done before. Tests showed a big rise in the stress hormone cortisol, and several of us saw our blood sugar levels soar into the diabetic range.

Things returned to normal after a good night’s sleep, but it was shocking to see the impact of just a few bad nights on our bodies.

Dr Eleanor Scott, who is Professor of Medicine at the University of Leeds and who helped run our experiment, told me that people who sleep less than seven hours a night are more likely to become overweight or obese and develop type 2 diabetes than those who get seven to eight hours.

She explained that sleep deprivation alters your appetite hormones, making you more likely to feel hungry and less likely to feel full. It can also make you crave sweet foods — hence the urge for custard creams.

In fact, just being awake when you’re not meant to be makes the body produce more cortisol, and that can influence your blood sugar levels the next day.

A big study by researchers at King’s College London found that sleep-deprived people consume, on average, an extra 385 calories per day, which is equivalent to a large slice of cake.

It’s not just that your blood-sugar levels soar and your hunger hormones go into overdrive when you’re tired; the areas of your brain associated with reward also become more active.

In other words, you become much more motivated to seek out unhealthy foods such as crisps and chocolate. The net result is you are more likely to eat unhealthy foods, and this excess is more likely to be stored as the fat in and around your abdomen (visceral fat) which is known to play a part in raising blood pressure and cholesterol, which in turn leads to a greater risk of developing type 2 diabetes, stroke and heart disease.

An important Swedish study of middle-aged women found the differences in sleep quality and quantity among the overweight was striking.

Women in the normal weight range slept 25 minutes more per night, got 20 per cent more brain-restoring deep sleep and 22 per cent more emotionally calming REM sleep than women who had a waist larger than 33 in.

SNORING MAKES THINGS WORSE 

Lack of sleep will make you fatter, but piling on extra fat (particularly around the gut and neck) also means you sleep worse. It is a vicious circle.

Being overweight also greatly increases your risk of developing sleep apnoea, a disorder that causes you to stop breathing for short periods in the night. This will make you really tired and hungry, and it is terrible for the brain.

I come from a long line of snorers. My father used to snore really, really loudly — it sounded like someone sawing logs and was loud enough to be heard on the other side of the house.

Lack of sleep will make you fatter, but piling on extra fat (particularly around the gut and neck) also means you sleep worse. It is a vicious circle [Stock image]

I also used to snore at an incredible volume; in fact, my wife said that when we lived in London, I snored so loudly I drowned out the sound of the metal beer barrels being delivered to the pub opposite our house first thing in the morning.

If you are a woman with a neck size over 16 in, or a man with a neck size over 17 in, you are likely to be a snorer.

The sad truth is, as we get older and fatter, we snore more. That’s because our throat gets narrower, our throat muscles get weaker and our uvula — that finger-like bit of tissue at the back of the throat — gets floppier.

All these changes mean that when we breathe in, the air can’t move freely through our nose and into our lungs. Instead, the incoming air makes the surrounding tissues vibrate, which produces that horrendous snoring noise.

This will disrupt your sleep and your partner’s sleep as well.

But this can change. When I lost my excess weight, I also lost an inch of fat around my neck, and the snoring stopped. Completely.

TIREDNESS AND SUGAR ADDICTION 

By living a life that is full of stress, you may find it extra difficult to control your weight and waistline.

That’s not just because of psychological pressures but also because cortisol, the stress hormone, itself can lead to raised blood sugars.

Persistently high levels of cortisol make your muscles and tissues more insulin-resistant (so they are less likely to respond to the hormone insulin which would lower blood sugar levels), and cortisol also stimulates your liver to release more sugar into your blood

This is all well and good if you’re being chased by a tiger and need some extra energy to run safely away.

But if you’re lying in bed stressing about the fact that your partner is snoring, or you just can’t sleep, the net result is raised blood sugar levels that put you at risk of developing type 2 diabetes.

This whole scenario feeds frustration, sadness and anger. To cheer yourself up — you eat more, and studies show that when you feel stressed you are far more likely to give into carb cravings and comfort eating.

Emotions such as stress, anger, fear and anxiety make us reach for the biscuit tin, which in turn will make our blood sugar go haywire.

I’ve investigated different ways to reduce stress and build up resilience. I find doing brisk walks — preferably with my wife and our dog — really helps, as does gardening.

I also do a breathing exercise, called 4-2-4, particularly when I am struggling to sleep.

All you have to do is breathe in through your nose to a count of four, hold your breath for a count of two, then breathe out through your mouth to a count of two.

Doing this for a couple of minutes will slow your heart rate and calm you down.

On top of that, I practise mindfulness. In recent years mindfulness, a form of meditation, has become incredibly fashionable among celebrities, business leaders and athletes. The reason is that it works.

By living a life that is full of stress, you may find it extra difficult to control your weight and waistline. That’s not just because of psychological pressures but also because cortisol, the stress hormone, itself can lead to raised blood sugars [Stock image]

For a 2018 study, researchers divided volunteers into two groups — one meditated daily and the other did not — and followed them for six months. Those who meditated saw significant improvements in their stress levels, their blood sugar levels and their insulin sensitivity also improved.

It is not for everyone, but with so much positive research, it is unsurprising that diabetes organisations across the globe encourage the practice of mindfulness.

I was sceptical before I began doing it, but I have now made it part of my life. You can join an online course or try downloading a free app such as Headspace or Calm, which will guide you through the process.

The sessions are short — at first it’s just ten minutes, then 15 minutes, and finally 20 minutes. You may be cynical, but it is worth trying. I find it reduces cravings and helps me to sleep better.

When I’m doing a mindfulness session, I sit in a comfortable chair, turn on my app, rest my hands on my thighs and close my eyes. Then, guided by the app, I spend the next few minutes trying to focus on my breathing.

I pay attention to the sensation of the breath going through my nostrils, filling my chest, expanding and contracting my diaphragm.

I try to stay focused on this task, and when I notice that my thoughts have drifted — which they do — I bring them back to my breath.

I try to treat thoughts like balloons that drift into my consciousness; once I have noticed they are there, I simply allow them to drift way.

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