Insulin and Fat Storage

Your body has two main fuels: glucose (sugar) or fat. The preferred source of fuel is fat, but under certain circumstances, we can shift the body to using more sugar rather than fat. At times, such as being chased by a rabid dog, this is a good thing. However, it’s not a good thing if sugar remains the main fuel for most of the day. Relying on sugar means you’re not burning fat.

Many people make lifestyle and nutrition choices that have basically locked up their extra stored fat in their fat cells, making it useless for energy. The only way you can lose fat is if you use fat. You’ll be unsuccessful at losing fat if you don’t burn fat, even if you eat fewer calories and burn more through exercise. You can lose weight, but most of the loss will come from lean body mass, or muscle tissue, not fat.

Fat Storage and Insulin

The most significant factor in fat storage is the level of insulin in the blood. Insulin has many effects on the body. With respect to fat storage, insulin increases the storage of fat in fat cells and prevents fat cells from releasing fat for energy. This is such a key point for people to understand that I’ll repeat it: Insulin increases the storage of fat in fat cells and prevents the cells from releasing it for energy.

Eight hormones stimulate fat utilization: epinephrine, norepinephrine, adrenocorticotrophic hormone (ACTH), glucagon, thyroid-stimulating hormone, melanocyte-stimulating hormone, vasopressin and growth hormone.

One hormone prevents fat utilization: insulin.

The pancreas releases insulin when blood sugar levels rise above normal. Optimal fasting blood sugar should be between 70 and 90 mg/dL. Following a meal, blood sugars rise in relation to the amount and type of carbohydrates consumed. Processed carbohydrates are absorbed faster, and tend to cause faster and greater rises in blood sugar. The pancreas releases insulin, which tells the muscle, liver and fat cells to take up the blood sugar (and fat if it’s available) and remove it from the blood. This is a normal process because elevated blood sugar is toxic for the body.

With a moderate amount of carbohydrates consumed each day, the pancreas can gently say to the muscles, liver and fat cells, “Please grab that sugar.” The pancreas is happy because it doesn’t have to work too hard to get its message across. The muscle cells, liver cells and fat cells are happy because they’ve got room to store the moderate amount of sugar. The individual is happy because energy levels throughout the day stay pretty consistent and he or she stays relatively lean.

Over time, when individuals eat excessive amounts of carbohydrates, especially processed carbohydrates, on a daily basis, the muscle and fat stop listening to the pancreas’ release of insulin, which is called insulin resistance. The liver and muscle cells have a limited capacity to store glucose. Once they’re full, they shut the door and it all gets sent to the fat cells.

Since blood sugar levels are not brought down to the level they should be, the pancreas “talks louder.” It releases more insulin than it should have to. It’s like when Mom and Dad need to raise their voices because their child hasn’t done what was asked the first time. With more insulin released, glucose levels can be brought down to a safe level again, at least for a while. Over time, fasting blood sugar levels start to creep up. Fasting blood sugar levels that start trending over 90 mg/dL can be a sign of early insulin resistance. Once they get above 100 mg/dL, most physicians will tell their patients they have insulin resistance.

As the years go by and excessive carbohydrate consumption continues, blood sugar levels get higher and higher. The pancreas has to yell at the fat cells by secreting even higher levels of insulin. Eventually the cells with receptors for insulin stop listening and/or the pancreas stops secreting insulin. Blood sugar levels rise, and when they get above 125 mg/dL, type 2 diabetes is usually diagnosed. Unfortunately, people don’t get enough support during the time they’re heading toward diabetes; it’s only after their blood sugar hits disease-state levels that they get attention, often in the form of drug therapy.

For someone with insulin resistance or diabetes, he or she will have an exaggerated insulin response. Eating a small amount of carbohydrate will cause the pancreas to release a large amount of insulin. Those who are insulin resistant will have elevated insulin levels throughout the day, which means their fat cells won’t be able to release fat for fuel.

Blood sugar problems often show up long before other symptoms, or even weight gain, so it’s wise to regularly check your blood sugar, and even insulin levels with a lab package.

Insulin locks fat in the fat cell. Excessive carbohydrate consumption causes elevated insulin levels. Remember that the next time you start to take a bite of a low-fat bagel.

Less Insulin, More Energy

If carbohydrates raise insulin levels and insulin increases fat storage and decreases fat burning, is a low-carb diet the answer to fat loss?

For many people, simply decreasing their carbohydrate consumption results in a decreased appetite, lowered insulin levels, improved lipid profiles and almost effortless weight loss. Once insulin levels are brought under control, fat cells are allowed to let go of their stored fatty acids. They still need to be burned somewhere, though.

Think of the lazy river at your favorite water park. The water moves freely, but it doesn’t really go anywhere. It just goes in circles. If you were to route the water somewhere else and use it in another pool, the water level in the lazy river would get lower.

If you open up the gates in the fat cells by lowering insulin levels, you now have an almost endless supply of energy available. It still needs to be used, though. Interestingly, many people proclaim how much more energy they have when they commit to a lower-carbohydrate diet. It’s especially common for those who are overweight. It makes a lot of sense, though.

When insulin levels are brought under control, it’s like getting a surprise inheritance of money after living paycheck to paycheck for years. After scraping by and keeping costs controlled from living off a meager salary, imagine how free one would feel being given a small fortune.

In Gary Taubes’ book Good Calories, Bad Calories, he explains that people become sedentary because they are gaining fat, they don’t gain fat because they are sedentary. The opposite way to look at this is once people control their insulin levels, they have the energy to become much more active. They don’t get active and energetic and then lose body fat.

There are less significant factors that affect one’s ability to access fat. That’s why we stress the importance of comprehensive lab testing to ensure one has a healthy, functional metabolism. However, controlling insulin seems to be the most impactful thing one can do to open up the fat gates and give the body access to the fuel stored behind them. Fortunately, you have a significant amount of control over your insulin levels by what you put in your mouth every day. If you base your diet on vegetables and protein. You won’t have to worry about rising insulin levels, and you will be able to burn fat the way your body was designed to.

In case you haven’t realized it already, none of what is mentioned above requires calorie counting; only the wisdom to make the right choices about the foods you eat.

Written By Tom Nikkola - Director of Nutrition & Weight Managemen