It’s a familiar festive scene… It’s early evening on December 25, time to rally the troops for a round of charades. Only, everybody’s groaning and loosening their waistbands, bloated, rosy-cheeked and half asleep in their seats.

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The whole family’s in a food coma. Those second helpings of roasties and pigs-in-blankets, devoured after a day grazing on Fererro Rocher and selection boxes (oh come on, it’s only once a year!) have left everyone zonked.

“We’ve all done it; a typical Christmas day scenario, we’ve eaten a delicious meal only to nod off in front of the TV,” says Silentnight’s sleep expert, Dr Nerina Ramlakhan. “While this might sound cosy, the reality is many people end up feeling uncomfortable, bloated, ill and even spaced. So many people say they ended up missing out on some of Christmas day as a result of falling into this ‘food coma’.”

So what exactly is happening during a food coma, or ‘postprandial somnolence’, as it’s properly known?

Food coma explained

Dr Nerina explains, when we eat, the stomach produces a hormone called gastrin that promotes the release of digestive juices. Then, as food enters the small intestine, gut cells secrete more hormones – enterogastrone - that signal other bodily functions, including blood flow regulation. This process makes us feel sleepy, because as food’s digested, blood’s diverted away from the brain and other organs to the stomach and gut to help transport the absorbed newly digested metabolites away.

So the more you eat, the more blood’s diverted (meaning more sleep-headedness!). But it’s not just the amount of food we eat, but the type of food consumed in one sitting, Dr Nerina notes, as different types of foods affect our hormones – which can impact energy levels and mood.

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From belly to brain

For example, meals high in carbohydrates that also have a high glycaemic index (meaning they release sugar into the bloodstream quickly) cause an increase in insulin, which promotes the absorption and use of glucose from the bloodstream after a meal, Dr Nerina explains. But it also allows entry of the amino acid tryptophan (produced from the digestion of proteins) into the brain. This is converted into serotonin, which can lead to sleepiness.

Dr Nerina Ramlakhan’s 5 top tips for avoiding a Christmas Day food coma:

1. “Don’t overeat: I know it’s Christmas but watch your portion size. Allow time during your meal for the level of your body’s natural hormones leptin (which reduces hunger) to rise, and ghrelin (normally only released when we initiate eating) to fall, thereby lowering your appetite and inducing a feeling of satiety.”

2. “Slow down your rate of eating – put your knife and fork down between each mouthful. Drink a glass of water before you start eating – this’ll pre-stretch your stomach, fooling your brain into thinking you’re more full than you actually are.”

3. “Don’t skip breakfast in the hope you’ll be saving on the calories. Eating a big meal when you’re in starvation mode actually makes you more sleepy and tends to promote overeating and more fat storage.”

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4. “Balance your meal; have protein and carbohydrate in roughly a one-to- two proportion. Load up on the veggies and have less of the high-fat sauces and gravy.”

5. “Avoid vegging out after the main meal. Once the meal’s settled, be moderately active. This will help promote better blood sugar control. Go for a walk or have a bop to some lively Christmas tunes.”

“And if all else fails, accept that it’s Christmas Day, be kind to your ‘food baby’ and start the next day with good intentions!”