You would think that the more time you spend in bed, the fewer calories you will burn and the more you’ll gain. However, the opposite is true. In fact, one of the best diets today, is sleep. Get proper amounts of sleep, and you’ll see the pounds disappear.
Sleep is one of the two primary sources of energy that our body needs to get through the day [the other being food]. Boosting our energy with sleep makes it easier for us to make healthy decisions throughout the day.
Rest and not just activity is a part of a healthy lifestyle. Francesco P Cappuccio and his colleagues at the University of Warwick Medical School found a correlation between short sleep and a higher body mass index [BMI]. This means that people who slept the least had the highest weight relative to their size and age. In 2005, collaborators including Dr Gangswisch at the Columbia University found that those who reported getting less than seven hours of sleep per night had a higher risk for obesity than their counterparts who caught sufficient ZZZs.
Sleep affects metabolism
Research has found that sleep deprivation has dire effects on our metabolism. Two hormones—leptin and ghrelin—help control how much we eat and influence the hunger we feel. Ghrelin works to modulate how temporarily hungry or satiated we are, while leptin helps with weight loss in the long term. Ghrelin accelerates hunger while leptin inhibits it. Both these hormones are connected to sleep. At the Stanford University, Dr Taheri and his colleagues found that those who slept less than eight hours at night had elevated ghrelin, lower leptin, and significantly higher body fat compared to well-rested participants.
Insulin is another hormone that connects sleep to weight maintenance. Insulin works to keep our blood sugar at normal levels. Van Cauter and colleagues Karine Spiegel and Rachel Leproult at the University of Chicago Medical Center found that healthy individuals who slept less than six hours per night experienced tremendous hormonal changes: their insulin production increased by 30 per cent to maintain blood sugar. Such lack of sleep predisposes people to weight gain, type-2 diabetes and other health issues.
The sleep and eating connection
Imagine it’s close to bedtime. Ask yourself: are you craving something to eat? Most likely it’s something sweet. Dr Eve van Cauter at the University of Chicago subjected healthy male participants to sleep deprivation and found a 24 per cent increase in their appetites. Moreover, the subjects craved sweet, salty and starchy foods like cookies, chips, and pasta the most. When sleep deprived, we crave foods high in fat and sugar. Plus, the longer we sleep, the lesser time we get to eat.
“Stress eating” is not just an excuse we use to eat how we like. This type of eating is an effect of stress on our biology and eating behaviour. When we don’t get enough sleep, our levels of the stress hormone cortisol are higher. And high cortisol levels trigger hunger.
Consumption of “comfort food” is another eating behaviour linked to sleep. When we don’t get enough sleep, the part of our brain that governs emotions like anger is more active. We have less control over our emotions and might find ourselves turning to food for comfort. This proves to be dangerous to our diets and health. Dr Brian Wansink at the Cornell University found that of the respondents he surveyed, only 40 per cent’s favourite comfort foods were ‘somewhat’ healthy.
Nutrition and sleep are not only connected by physiology, but also by psychology. Eating is a behaviour; one that nutritionists and psychologists alike have argued is heavily influenced by the food environment we are in. Our eating behaviour is often dependent upon external cues, sometimes regardless of how hungry we are. For example, researchers Van Ittersum K and Wansink B found that the size of our plate unconsciously determines how much food we put on our plate and therefore how much we consume. These environmental influences are problematic to our health and nutrition because we live in an obesigenic environment.
We are constantly surrounded with cheap, convenient, and high-calorie foods begging us to taste them. But if we want to lead a healthy lifestyle, we often have to ignore these cues. When we are exhausted from inadequate sleep, we may be even more susceptible. Mark Blagrove at the University of Wales found that subjects who had been awake for 21 hours were significantly more suggestible than their well-rested counterparts. So when we are passing advertisements for poor food choices, being well-rested may help us not only physiologically to make better food choices [by reducing our craving], but mentally as well.
A major factor that influences the daily decisions we make about food, is convenience. After a long, tiring day, it is appealing to eat something quick rather than take the effort to cook. Those who change their sleep habits, however, find it easier to manage time effectively—giving them more energy to spend on things that often fall by the wayside, such as a wholesome meal. By boosting energy with added sleep, we can be less reliant on convenience and make healthier decisions.
Health and nutrition are, of course, controlled by many different factors, some of which are out of our control. This includes our genetics, environment, culture, stress and costs. The ties between sleep and healthier eating habits show that part of the solution to weight issues may be in harnessing the power of sleep, and not in avoiding it.
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