Leptin is a protein hormone that acts to regulate appetite, metabolism and energy levels. If leptin is doing its job properly, it signals the brain how much energy your body has and how much is required - in other words, whether you need to eat because you are low on energy or whether you have enough energy and do not need to eat any more. In the latter case, it should signal satiety. Because it is manufactured primarily in the fat cells, the amount of leptin in your body is directly related to the amount of body fat you have.
You would think that would mean that the appetite would decrease, but that is not the case. Unfortunately, for some of us, our bodies have become deaf to the leptin's message that we are full and should stop eating - our cells are unable to accept leptin's satiety messages and we keep eating. In fact, most obese people have high levels of leptin and have become leptin resistant, in a similar way that some diabetics have become resistant to insulin.
A WebMD article on appetite hormones levels quotes Louis Aronne, directory of the Comprehensive Weight Control Program at New York-Presbyterian Hospital: "With leptin resistance, you don't feel full and the more you eat, the hungrier you may get." Further, the article quotes Scott Kahan, co-director of the George Washington University Weight Management Program: "The general public tends to think of 'fat' people as lazy and as having no willpower [but] it couldn't be further from the truth...There is no question that certain people are preconditioned to gain weight more easily and more quickly regain weight after dieting."
So, what to do? It will come as absolutely no surprise that a proper diet and exercise were mentioned again and again as the key. Almost all of the articles I read also recommended that snacking be limited and that one should eat three well-balanced and nutritiously healthy meals, making sure to get plenty of protein. I don't know about this part of the recommendation - it is certainly not what I do, even though I am pretty sure that if I am not now still leptin resistant then I certainly was in the past. I actually eat 6 - 7 times a day consisting of three medium-sized meals and three or four small snacks. I'm not sure what the rationale is behind the three meals only recommendation, just passing on what I found in my reading.
Some Links:
Alternative Health for Today: Insulin and Leptin Resistance - Information Worth Knowing
Sharecare: What is Leptin Resistance
Suite101: Overcome Leptin Resistance with Exercise
WebMD: Some Dieters Are Set Up to Regain Weight
Harvard Gazette: Shining Light on Leptin's Role in the Brain
eHow: How to Check Leptin Levels
