Updated: Jun 14, 2021
3. Lack of Exercise:
It may be counter-intuitive that the lack of exercise makes you hungry so let me explain.......
Our bodies have 3 ways, primarily, to store energy:
1. Food "prepared and ready to eat." This is your blood glucose. Did you know that you have very little glucose circulating in your blood. The body's blood sugar range is carefully controlled in a healthy individual, which will usually measure 80 mg/dl in the blood. So, how much actual sugar (or glucose) is in the body?
The human body contains approximately 5 liters of blood. This amounts to 4 grams of sugar in the blood, which is less than a teaspoon of sugar! This isn't enough "fuel" to keep you running very long. Therefore you either have to keep eating to replenish your blood sugar or your body will find fuel elsewhere in your body. It's there. Keep reading to find out where: https://tinyurl.com/yxzbmcpy
2. Food "in your internal refrigerator." We store fuel in our liver and muscles so we continue to have energy as we deplete the "food prepared and ready to eat," that is, our blood sugar. This food in our refrigerator is called glycogen. One glycogen molecule can consist of long chains of 1,700 to 600,000 glucose units. About 0.5 percent of the weight of your muscles and 5 percent of the weight of your liver are made up of glycogen. That's it! You have fuel reserves by way of glycogen. https://tinyurl.com/yxtrwr5y
3. Food "in your freezer." We convert excess sugars to fat in our liver, after we stock up with food reserves as glycogen. Again, our body knows that having too much circulating glucose in our blood vessels is harmful. This is similar to the oxygen we breathe. If you are at sea level, you are breathing air that is approximately 21% oxygen by composition. If you are on top of Pikes Peak, you may be "struggling" for air. Here the oxygen level is much lower than 21%. Also, it's not healthy to take in 100% oxygen or even oxygen levels above 21% - it's "oxidizing." Dr. Hyman (MD) says it causes "rust." So both glucose and oxygen, two of the most common substance our bodies needs - have optimal ranges.
When glucose intake exceeds your body's energy needs - for example, you eat pancakes with high fructose containing syrup, and then go relax on the sofa for five hours - your body has little need to create more energy molecules. Therefore, your body begins the process of converting these "sugars" (glucose) to triglycerides that are eventually stored in the fat tissues of your body. These triglycerides are stored energy molecules which can be broken down later to give you the energy you need. https://tinyurl.com/y3nb6stl
OK, so how does all this make and keep you hungry?
Even if you are sedentary, your cells are working constantly - burning calories. You aren't eating constantly though and you don't have a lot of sugar in your blood - we established that (see 1. above). Therefore, to keep you going, your body pulls from glycogen reserves first.
When you exercise or are active, your muscles "stock up" on glycogen for the next physical activity. A muscle, if you use it, it will respond by getting stronger and bigger. The same is true of your glycogen reserves. Athletes may have more than four times the amount of glycogen in their muscles and liver compared to sedentary people, which gives them more endurance when they are exercising. But, these glycogen stores keep the active person from getting hungry between meals. A highly trained athlete may have 3+ hours of glycogen in reserve whereas the sedentary person only has a 30-minute reserve.
You have very little sugar (glucose) circulating in your blood ("food on the table")
Short term sugar storage is called glycogen ("food in the refrigerator")
When you exercise you increase your body's ability to store sugar, as glycogen, for quick use and energy between meals.
If you don't exercise you run out of sugar (including glycogen), feel tired, hungry, and reach for more food.
Simple Solution: Move daily.
I recommend high intensity and weight-bearing exercise to maximize glycogen storage. Check with your healthcare professional to determine what level of intensity is right for you. They often don't know how to advise you and will suggest that "less is better" to be safe - but will encourage movement. A strategy, that meets most healthcare professional's advice, for those of you who are sedentary, is to slowly increase the amount and intensity of your exercise and your body will adapt properly to the change.
Move to get or stay well - it's worth it!