Trouble sleeping? Check your diet: How nutrition affects falling asleep

Many people don't think about the fact that what we eat during the day directly affects the length and depth of our sleep.

The relationship between sleep and nutrition

"It's a vicious circle," explains Dr Marie-Pierre St-Onge, associate professor of dietetics at Columbia University (New York). - If you don't sleep well, you're likely to reach for foods high in calories, fat or sugar during the day. And consuming such foods, in turn, impairs the quality of your sleep the next night."

The glycemic index: the key to understanding it

The focus is on carbohydrates and their glycaemic index (GI), which reflects how quickly a food raises blood sugar levels. Foods with a high GI (white bread, potatoes, many processed breakfast foods) cause spikes in glucose and insulin, while whole grains, legumes, high-fibre fruits and vegetables tend to have a low GI and have a milder effect on sugar levels.

A study in the American Journal of Clinical Nutrition (2020) found that in postmenopausal women, a high-glycemic diet may increase the risk of insomnia. Another review found: if a person sleeps less than 5.5 hours per night, their total calorie intake increases, as well as their fat, protein, and carbohydrate intake.

Why does lack of sleep encourage unhealthy snacking?

Scientists explain that lack of sleep and fatigue can "interfere" with the hormones that regulate hunger and satiety. An earlier study by St Onge found that in men, short sleep increases levels of ghrelin (the hunger hormone), while in women the concentration of GLP-1, responsible for feelings of satiety, decreases.

What's healthier to eat to sleep better?

• Whole-grain foods and legumes: they help maintain normal blood sugar and create a long-lasting feeling of satiety.
• Mediterranean diet: focus on fruits and vegetables, low-fat dairy products, fish and olive oil. Studies confirm that this diet often correlates with better quality sleep.

But nutrition is not the only factor

In addition to diet, sleep is affected by a number of things: stress, lack of exercise, noise, smartphone screen brightness before bed, and more. If food has become a suspected factor, doctors advise keeping a "sleep and mood diary," noting what was eaten and drunk during the day, as well as indicating how you feel and the quality of your sleep.

The general rule of thumb isto eat fewer "fast" carbohydrates, more whole grains and legumes, and a minimum of late and heavy dinners. This can be one of the easiest steps towards a restful night's rest and a more awake morning.