Before we get ahead of ourselves, I need you to do me a favor- point your google at “hyperinsulinemia, disease” and I’ll be right here. It’s ok, I’m patient.
Pretty scary, huh?
Diabetes. Cardiovascular disease. Alzheimer’s. The dread Syndrome X… and that was just the first page of results!
That’s where this story ends but I want to tell you where it begins and how it happens.
Simply put, insulin is a hormone that helps keep blood sugar in check. Insulin tells your muscles, liver, and fat cells to gobble up the glucose (from carbohydrates and other sugars) in the blood stream and store it as fat by decreasing the ability of the pancreas to release another hormone, glucagon, which tries to lower blood sugar levels. It is kind of a teeter-totter relationship
Insulin also works to direct the use of fat and protein in the body. Insulin makes sure your muscles get the protein they need to maintain minimal homeostasis and that you store enough energy to get you to your next meal. It does this in part by utilizing two different enzymes lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL). LPL spends its day hanging out on the membranes of different cells and grabs fat from the blood stream and then puts into whatever cell it is attached to. If it is on a muscle cell, the fat goes into the muscle, if it is on a fat cell- the fat cell gets fatter. HSL can be thought of as the antithesis of LPL; Where LPL looks to stockpile fat HSL tries to slim us down. I bet you can guess the impact insulin has on HSL, so you won’t be surprised to learn that is only takes a small amount of insulin to completely derail the work of the lowly HSL enzyme.
Interestingly, sex hormones play a large part in where LPL collects in men and women. Testosterone suppresses LPL activity and LPL tends to accumulate above the waist. As a man gets older and produces less testosterone, the LPL is better able to snatch up the passing fat which then accumulates in that glorious belly so many men lug around. In women, LPL accumulates mostly in the tissues below the waist, especially so during pregnancy.
LPL also helps us understand why exercise alone won’t make us leaner. When exercising, LPL in muscle tissue takes center stage, allowing for the release of fat from adipose tissue which then provides the necessary fuel for the muscle. After working out, the LPL activity in fat cells increases in tandem with the protein demand from freshly worked muscle and our appetite gets a boost. Insulin suppresses LPL activity on muscle tissue and not surprisingly, the more insulin we secrete the more it inspires the LPL on adipose tissue to store fat.
The more insulin we secrete the better able our adipose tissue gets at storing fat and just so we don’t run out of space to warehouse it all, insulin also helps create new fat cells.
In so many words, insulin makes us fat.
The Bitter Cycle
1) You think about eating a meal containing carbohydrates
2) You begin secreting insulin
3) Insulin signals the fat cells to shut down the release of fatty acids (inhibiting HSL) and take up more fatty acids (LPL) from the circulation
4) You start to get hungry, or hungrier
5) You begin eating
6) You secrete more insulin
7) The carbohydrates are digested and enter the circulation as glucose, causing blood sugar to rise
8) You secret even more insulin
9) Fat from the diet is stored as triglycerides in the fat cells, as are some of the carbohydrates that are converted into fat in the liver
10) The fat cells get fatter, and so do you
11) The fat stays in the fat cell until the insulin level drops (Taubes, p.122-123)
Adiposity from a different perspective
Too often, we look at weight retention in almost moralistic terms- A person is fat because they are slothful and gluttonous. How else can it be? After our discussion concerning the insulin response in the body it becomes much less clear cut.
We aren’t fat because we are lazy and eat too much; we eat too much and are lazy BECAUSE we are fat.
Insulin tells our body to store store store. If insulin levels always remain elevated we are never really able to utilize fat or protein for fuel because they are trapped in the adipose tissue and muscle cells. We can’t even use any stored carbohydrates because insulin keeps them under lock down as well and the net result is HUNGER.
So we eat (but we never really get the nutrients that our body needs) and we eat some more. It is like trying to cobble together 100% of our nutrients from 100 different meals 1% at a time. This is often seen as gluttony but to be more precise, it is simply a response to elevated insulin levels.
If we aren’t getting enough energy from our diet the body really only has one choice- decrease activity level. This is often seen as sloth but to be more precise, it is also a response to elevated insulin levels.
With elevated insulin levels the only nutrients our cells can actively use are new carbohydrates coming in, and the cycle continues on.
Thus, we get fatter and fatter, our energy level plummets, and it is all because our body is doing exactly what it is being told to do by the insulin response.
Works Consulted: “Why We Get Fat” by Gary Taubes
READ THIS BOOK!!!
written by T