Change WHEN you eat, not WHAT you eat

Change your mealtimes

Would you be prepared to bring your evening meal earlier, have a later breakfast, and skip late night snacking? It might be harder than you think – but the benefits are worth it!

In the latest episode of Just One Thing, Dr Michael Mosley finds out that simply adjusting when you eat can help you lose weight and improve your metabolism. Studies are showing it has the potential to lower your blood pressure, improve your sleep, help with weight loss, and even cut your risk of developing type 2 diabetes.

The fasting window

It’s often called time-restricted eating and it’s a new and promising area of research. The key is to have dinner earlier and breakfast later, thereby giving your body a short overnight fast. Encouraging results have been found for overnight fasts between 12 to 14 hours long, but experts suggest that even just simply pushing back breakfast and bringing forward dinner by an hour each way, your body is likely going to feel the benefits.

The research

The idea that just changing when – and not what you eat – first began with experiments on mice and it’s only in the last couple of years that there have been a growing number of human clinical trials. So far, the results have been astonishing. Dr Emily Manoogian who heads the clinical trials at the Salk Institute in California says they have observed weight loss across the board. One study found an average weight loss of 3.3kg over 3 months, alongside significant improvements in markers of cardiovascular disease and diabetes.

Another study, this time from the University of Surrey, found positive improvements in the participants’ blood sugar and cholesterol levels after just 10 weeks of time-restricted eating.

Get your rhythm right

Light, as we know, has a huge impact on our body clocks. Food is another cue that can inform our internal circadian rhythms. And eating late at night or early in the morning can really throw our sleep-cycle out of sync. If you’re still digesting food late at night while your body is trying to rest, that can cause real trouble, as your body and mind can’t rest as well.

As Dr Manoogian explains, “Food is a stimulatory cue to your brain to tell it it's time to be awake.” Making sure that you stop eating three or four hours before you go to sleep could also greatly improve the quality of sleep you get. It’s not just about avoiding food late at night, it’s about keeping your body working to the same rhythm and timings every day.

How does it work?

“Physiologically, even mentally, we are a different person at different times of day,”says Dr Manoogian, and the effects are more drastic than you might think. At night and when it’s dark outside, your body starts making the sleep hormone melatonin. This prevents your body from releasing insulin which, if you’re eating late at night, isn’t a good thing. Without it, fat and sugar will hang around in your bloodstream for far longer, and increase your risk of diabetes and cardiovascular disease.

The most important thing is to choose an eating window you can stick to, so you can help keep your circadian rhythms in regular order.

Messing with your body clocks can also lead to other problems like chronic inflammation, which can cause problems in and of itself. “Your body’s circadian system is there to make sure everything's happening in the right place at the right time. And time-restricted eating is really there to help support that,” says Dr. Manoogian.

Giving your body a rest at night is also very important for its repair systems to kick in. “Sleep is a time for your body to rest and repair,” says Dr. Manoogian. “If you're going to repair a road, you need the cars to stop driving on it!”

The key is to work with, not against, your body. You can reduce the harmful effects of a sweet treat just by picking when to eat it.

How can I try it?

It’s undoubtedly one of our trickier tasks, but, if you’re up for the challenge, Dr Manoogian has given her top tips to make it work for you. The most important thing is to choose an eating window you can stick to, so you can help keep your circadian rhythms in regular order. When you wake up, wait for at least one to two hours before eating breakfast, and if you can, try to eat more of your calories in the first part of the day. Ensuring you get a solid eight hours of sleep will also help bolster the positive effects – and the good news is that simply cutting out the late night snacks can go a long way.

Time-restricted eating might work wonders for some, but it won’t be suitable for everyone. Check with your GP if you’re on medication, or have any concerns, before trying it out for the first time.

To learn more, listen to Just One Thing - with Michael Mosley: Change Your Mealtimes