Summer is here and most of us want to feel more comfortable in our skin. Layers of clothing are coming off and days at the beach are in your future. The key to feeling lean and losing those last pesky 5 pounds is something you’ve probably never even thought about: insulin.
It’s not just something diabetics have to keep tabs on; you should too if you have fitness goals of losing body fat or losing weight.
Insulin affects how our bodies look, especially around the midsection. If you’re trying to lose a couple of pounds or get out of a weight loss rut, getting hold of your insulin levels may just be the ticket.
What is Insulin?
Insulin is a hormone, released by the pancreas, that regulates how you metabolize carbohydrates. It’s also the hormone responsible for storing fat.
After you eat a meal, insulin converts any carbohydrates eaten into glucose (a form of energy for your body). Any energy that isn’t used immediately is stored in the form of glycogen. Glycogen is stored in muscles and your liver until it is needed. Because your body can only store so much glycogen, insulin then begins to store excess energy as fat.
Since insulin is a fat-storing hormone, it inhibits cells from releasing fat to be used as energy. This means insulin must be kept low in order to burn fat. To keep insulin low, it’s important to eat the right foods and make sure your body is able to metabolize carbohydrates efficiently.
How efficiently your body metabolizes carbohydrates is dependent on your insulin sensitivity.
Insulin sensitivity has to do with how well your body responds to insulin. If you’re highly sensitive, then you need less insulin to store carbohydrates. This means you are able to eat carbohydrates without a large increase in insulin. Keeping insulin low allows your body to release fatty acids to be used as energy, which results in burning fat.
If you are insulin resistant (such as type 2 diabetics), then your body requires larger amounts of insulin to store carbs. More insulin is required to break down carbohydrates, which means your insulin levels will go up. When insulin is high, your body won’t release fatty acids and you will no longer be burning fat.
A diet that has a moderate amount of healthy carbohydrates allows your pancreas to slowly release a small amount of insulin throughout the day. This means your body is highly sensitive to insulin, allowing your liver and muscles to use the glucose efficiently and without excess insulin being released. Your pancreas and your body is happy because it doesn’t have to work too hard to metabolize those carbohydrates, and your body receives a steady amount of energy throughout the day.
Unhealthy and processed carbohydrates contain higher amounts of sugars, which raises glucose levels in the blood. With more glucose in your system comes a higher level of insulin. Your body will become insulin resistant and will continue to require even MORE insulin to bring down raising glucose levels. Your liver and muscles will also start to fill with glycogen, and because they can only store so much glycogen, the excess glucose in your system gets stored as fat. Fat burning is brought to a halt, and fat storing has begun. (1)
So if carbs raise insulin levels and insulin increases fat storage and decreases fat burning, wouldn’t a low carb diet be the answer to fat loss?
Here’s the tricky part: carbohydrates are needed for things such as high-intensity workouts and long endurance workouts. So it’s important to consume enough carbohydrates for fuel, but to still keep insulin low enough to burn fat. The best way to do that is to eat “healthy carbs” at the right times to provide plenty of energy. (2)
How the Glycemic Index Affects Insulin Levels
When trying to lose weight, or decrease body fat percentages, it is important to choose carbohydrates that will keep insulin levels low and to maintain a moderate carb intake to keep energy up. Choosing the right carbohydrates depends on the glycemic index of the carbohydrate.
The glycemic index (GI) ranks carbohydrates on a scale from 0-100 based on how they affect blood sugar levels.
- Low Glycemic Foods (“Healthy Carbs”) break down slowly while digesting, allowing a steady stream of glucose to enter the bloodstream, preventing spikes in insulin.
- High Glycemic Foods (“Bad Carbs”) break down quickly and cause glucose levels to raise quickly, requiring insulin levels to rise quickly as well.
Low Glycemic Foods are those that are rated between 0-55. Examples are most vegetables and fruit, whole grains like quinoa or barley, beans, and legumes.
High Glycemic Foods are rated from 55-100 and are mostly processed foods like white bread, corn flakes, crackers and most dessert foods.
As stated before, when insulin is high, fat burning decreases. So, insulin released after eating carbohydrates directly correlates to the GI of the carb and the amount of carbs eaten. The higher the GI of a food, the quicker your blood sugar levels rise and the more insulin is released. So choosing low glycemic foods will keep insulin low, and fat burning high.
Not only will low glycemic foods improve your body’s ability to lose fat, but they’ll also control cravings and provide energy all day.
When you eat a high glycemic food there is a sudden surge of insulin, followed by a sharp dip in insulin. These drastic spikes in insulin levels can trigger feelings of hunger and cravings for more sugary and carb-rich foods. They are also responsible for “sugar crashes”, making you feel tired and fatigued.
Low glycemic foods provide a steady source of energy throughout the day because they metabolize slower. This helps to control your appetite and makes your body perform better throughout the day and in your workouts.
Eating low glycemic foods and controlling your insulin will allow your body to burn fat most efficiently and will ensure weight loss and lower body fat percentages. (3)
Combining Foods to Lower Insulin Levels
The glycemic index doesn’t tell the whole story, though. The GI of a food is only measured when that food is eaten by itself, not when eaten in a meal. So, luckily, there are ways to work around higher glycemic foods.
Eating protein, fat, or other nutrient-rich foods can greatly affect the GI of the carbs in your meal. When you are eating a higher glycemic food, you can combine it with low GI foods to help balance the meal and slow down carbohydrate digestion and absorption.
When carbohydrates are combined with low glycemic foods such as proteins, fats, or fruits and vegetables, the glycemic index of the entire meal will drop as a whole. Combining other foods with carbohydrates will slow the digestion of the carbohydrates, and help keep blood sugar levels stable, controlling the release of insulin. (4)
Fiber also decreases the rate at which carbohydrates are digested. When a carb or meal is high in fiber and includes foods such as fruit, vegetables, and whole grains, the fiber acts as a sort of buffer during glucose absorption and slows the whole process down. Fiber-rich carbohydrates will also help keep you feeling fuller for longer, which prevents cravings and overeating. (5)
How to Control Insulin Levels
A great way to regulate insulin levels would be to try carb cycling, where you manipulate your carb intake to work with your fitness training program so that you will be eating most of your carbs when your body is most sensitive to metabolizing them. Find out more about carb cycling here.
You can also make sure to eat plenty of lower glycemic foods, mostly fruits and vegetables. Luckily, on a Paleo diet plan, many of the carbs you will be eating are already lower on the GI chart. Also, make sure to combine higher GI foods with protein and fiber to control insulin levels even more.
Follow these steps to gain control of your insulin levels and finally surmount that plateau.
(Related: 4 Reasons Why You’re Not Losing Weight)