I feel if you are over-fat then you almost certainly have a problem with how Insulin Sensitive you are. Insulin as you probably know is a hormone secreted by the Pancreas, you can get an insulin response to almost anything you eat, including proteins! This always comes as a shock to the paleo tribe but this is made very clear in the the insulin index, which first made its appearance in a 1997 American Journal of Clinical Nutrition which was primarily the creation of Susanne Holt, a graduate student at the time and now a doctor. Interestingly, Holt, her supervisory co-authors, or other researchers haven’t chosen to conduct further research to update the “preliminary” results of their insulin index study since its creation eleven years ago now.
While Holt and her co-authors found a high correlation between glycemic index and insulin index measurements, they stumbled upon an intriguing exception. High protein, virtually no-carb foods like meat and eggs, while low on the glycemic index, measured high quite on the insulin index. In other words, while the meat and eggs didn’t cause a spike in blood sugar the way most carbohydrates do, they did result in an unexpectedly significant rise in insulin.
Insulin is an essential hormone, without being able to produce it, we would be a Type 1 Dietbetic and need insulin to prevent us going into Ketoacidosis, a dangerous and potentially fatal state for the body. It promotes the storage of nutrients which in our natural, primal state, this was an essential process. Even in our modern lives, this storage process is still vital. (We just have a nasty habit of flooding the system these days.) In the case of high protein foods, it makes perfect sense that the body recognizes the need to store amino acids. Now bearing in mind the fact that Proteins will secrete insulin, but carbohydrates do so even more, we tend to have a serious insulin management issue going on.
In an insulin sensitive body, the insulin will bind with Insulin receptors on your bodies cells. When a cell has insulin attached the cell will activate other messengers (helpers if you like) which allow glucose from the blood stream to enter into the cell and be used for energy. Sounds good eh?
Well yes, this is very useful unless you have Insulin resistance. This occurs when the cells are less affected by insulin and the cells receptors don’t bind as well to the insulin. This leads to a bit of a vicious circle. The cells are now less capable of binding onto Insulin and thus open the door for glucose to come into the cell to be used for energy, thus their is more glucose floating around in the blood stream and this can become toxic to the body. The body responds by releasing more and more insulin to deal with this increase of glucose in the blood basically thinking more “keys” are needed to open the “locks” to the cells to allow the glucose in, sadly though many of the locks are simply worn out and broken. This leads to high levels of both glucose and insulin circulating in the body and now the insulin triggers the release of Cortisol (your stress hormone, much more on this later) and your high blood glucose will get stored as fat, energy levels will also be low as the cells are not getting in the energy they need.
I believe insulin sensitivity is a big problem in modern life and I also believe it can be improved upon quickly. This piece of research in 2011 via the journal Obesity (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3139783/)
Compared groups eating a high protein/low carb diet and were instructed to eat until full Vs a Low fat calorie restricted diet. The high protein (eat until satisified) group had better weight management, better insulin health and fewer cravings for sugary and high carbohydrate based foods.