Sleep each night Insufficient number And how do most people love to read: initial study found that people who average less than seven hours of sleep a night. Or more than nine hours Have more health problems However, excessive sleep is the cause of poor health caused health problems have higher rates of obesity, heart disease and depression. But the main problem is that their depression, insomnia, people with depression often take sleep more. And they tend to overeat. And too little exercise And thus become obese obesity.