How sleep loss leads to weight gain
Poor and insufficient sleep can cause people to gain weight – that’s been well-established by research. But now scientists from the University of California, Berkeley have taken the analysis a step further, conducting a study of the neuroscience behind the sleep-weight connection. And they’ve found that a sleepy brain responds more strongly to junk food and has less ability to rein in the impulse to avoid it.
This study recruited 23 healthy men and women and assigned them two different sleep cycles, with each experience separated by a week. The first group came to the lab and got a normal eight-hour night of sleep before waking up to a normal breakfast of toast and strawberry jam. They were then shown 80 pictures of a variety of foods and rated how strongly they wanted each, while their brain activity was measured.
For the second sleep experiment, the participants stayed awake throughout the night and were given snacks to offset calories they burned while not sleeping. When they were shown the same images, they strongly preferred high calorie foods, such as desserts, chocolate and potato chips. The sleepier they were, the more they wanted to eat junk food.
The brain scans observed that the sleepy subjects had intense activity in the amygdale, which regulates basic emotions and the desire for food and experiences, and reduced responses in the cortical areas of the frontal lobe, which affects decision-making.