压力为什么能让你变胖?
每天要面对来自生活、工作的压力对于很多现代人来说已是家常便饭,但随之而来的是由压力引起的健康隐患,包括睡眠不足和心脏疾病等。你知道吗,除此之外,压力还可以使人的体重增加,甚至导致肥胖?
Have you ever had a stressful day? Many people do in the course of their daily lives. And on these high-pressure days, they might find themselves reaching for a sugary snack. Perhaps this is part of their daily routine. Or perhaps on this particular day, their self-control is a bit low and they feel compelled to take a sugar hit.
Stress is natural. That feeling of strain or pressure is a biological response, and under the right circumstances can be a great source of motivation. However, too much stress, especially chronic stress, has been linked to sleep disruption, a higher likelihood of a stroke, heart-attack, ulcer or depression, among other things. But why should stress make a person comfort eat?
Dr Giles Yeo, a member of the BBC's Trust Me, I'm a Doctor team, got together with scientists from Leeds University to conduct an experiment into the effect of stress on blood sugar. Dr Yeo was subjected to a stress test. In the first stage, he was forced to answer mathematical questions rapidly. In the second, he had to immerse his hand in a bath of ice-cold water for a period of time.
Before and after these tests, the Leeds scientists would measure Dr Yeo's blood sugar levels. These are the levels which rise when we eat as our body takes in the energy of the food. In a healthy person, these levels quickly return to normal. However, when Dr Yeo was being deliberately subjected to stress, his blood sugar took six times longer to drop than on a stress-free day.
When we become stressed, our bodies enter 'fight or flight' mode. Because our body believes it's under attack, it releases glucose into the blood to provide energy for muscles. However, if we don't use that energy, our body then releases insulin to make the blood sugar levels drop. This drop causes a hunger response: you want to eat. And what you particularly crave is sugary food, which rapidly replenishes the energy you have lost. If this happens repeatedly, over a long enough period, these high-calorie foods can lead to obesity.
So what can we do to combat the stress? In an article for the BBC, Dr Michael Mosley recommends 'stress-busting' techniques, like exercise, gardening, mindfulness or another activities that you enjoy. But his strongest recommendation is trying to get a good night's sleep. A recent study carried out by researchers at King's College, London found that if you deprived people of sleep, they would consume, on average, an extra 385kcal per day, which is equivalent to the calories in a large muffin. So, try sleeping to decrease stress, and as a result make it easier to keep yourself a little trimmer.