You would think that staying awake longer would cause you to lose weight – and it may if the reason you are awake is stress that has excess adrenaline and cortisol coursing through your veins – but research has found the opposite to be true. People who sleep less than 6 hours a night are more likely to gain weight than those who get 7 or 8 hours. Why is this? And no, it's not the extra hour or two of snacking! One explanation involves the hormone leptin.
Researchers found that sleep reduces ghrelin (a hormone that increases appetite) and increases leptin (the hormone that suppresses appetite and increases burning rather than storing of fat). The short sleepers were hungrier and snacked more, and preferred high-carb snacks. Lack of sleep also increases the risk of insulin resistance (which I have written about in several previous columns), Type II Diabetes, and high blood pressure.
Leptin is released from fat cells when fat is stored in them. A diet high in sugars and other simple carbohydrates results in a large amount of leptin being released, in an attempt to curb your appetite. At some point your body becomes resistant to leptin (similar to insulin resistance) and the leptin signals telling you to stop eating are ignored (like a stuck thermostat). You stay hungry and keep piling on the fat. When tested, almost all overweight people had ample leptin levels, but it wasn’t doing its job because of leptin resistance. Leptin resistance is now known to be a factor in many health problems besides obesity: heart disease, blood pressure, diabetes, osteoporosis, inflammation and aging. And leptin is the most likely suspect for regaining fat after losing weight on a conventional diet (the yo-yo effect).
The role of leptin in weight management, and how to control it with diet, is explained in detail in Dr. Ron Rosedale and Carol Colman’s 2004 book “The Rosedale Diet”. The key is a diet high in good fats with the right amount of high quality protein and healthy carbohydrates. And don’t forget your 8 hours of sleep!
This article is intended for educational purposes only; for medical advice consult your licensed health practitioner.