Blood sugar levels vary during the day, they are the lowest in the morning and before meals, and they rise after meals. Blood sugar, i.e. glucose, is stored in kidneys, muscles, and fatty tissues with the help of insulin which acts as a key that opens the doors to our cells so that glucose can become a source of energy. When we eat food that is rich in carbohydrates and sugars, this is to say a lot of glucose, blood sugar rises, and a large amount of insulin starts to produce. If we do not use this sugar, it stores in the fatty tissue. At the same time, as our blood sugar level increases excessively, it will also decrease in a few hours and we will have a desire to consume even more sugars.
Storing of fatty tissue may also trigger insulin resistance as fatty cells release inflammatory molecules which reduce cell's response to insulin. As a result, the blood sugar in the circulation increases, and the pancreas produces even more insulin, leading to a vicious cycle of increased blood sugar, a reduced response to insulin, and storing excess fatty tissue. Prolonged increased levels of blood sugar in the circulation causes damage to the vascular and nervous system and vital organs.
It is important we make sure that the fluctuation is not too great, but to maintain it all day, without any sudden spikes. This can be best maintained with proper nutrition.
Guidelines for maintaining blood sugar levels:
We should avoid eating sweet fruit or simple carbohydrates for breakfast
Even though it is recommended to eat fruit in the first half of the day, we must be careful that we don't consume too much of sweet fruit (e.g. pineapple, banana...) first thing in the morning, because this excessive increase in blood sugar will later fall and our desire for sweet food will increase and make us binge on simple sugars. All berries, apples, or other fruit with a low glycemic index are a good choice in the morning. However, only fruit for breakfast will not fill us sufficiently, so later we can continue with something that contains many healthy fats in combination with proteins or whole-grain carbohydrates. Everything eaten for breakfast will be released during the day. It is recommended to eat breakfast between 7 and 9 am.
Avoid carbohydrates in the afternoon
We need to limit the consumption of carbohydrates after 3 pm. We need to consume energy from carbohydrates for breakfast and lunch. Focus on cooked, baked, or steamed vegetables for dinner. It is recommended that we eat the last meal of the day before 7 pm.
We should eat breakfast like kings, lunch like farmers, and dinner like beggars.
The glycemic index of a certain food shows how fast the blood sugar levels increase. The smaller the index, the slower it is released, and the slower the glucose levels increase, the less it fluctuates. Food with a low glycemic index is, therefore, healthier and won't give us sugar cravings. Food with a glycemic index lower than 55 is considered low glycemic food. For example, most fruit and vegetables, nuts, seeds, whole grains...
Reduced calorie intake
Daily calorie restriction of more than 20% of calories consumed has a positive effect on people who are overweight as this has a beneficial effect on insulin levels, blood sugar, and insulin resistance. Weight loss is an important step in regulating and breaking the vicious cycle in which insulin and blood sugar are caught.
Intermittent fasting is a shorter exchange of fasting and eating. For example, fasting 16/18, where we fast 16 hours a day and eat normally for the rest 8 hours or 1-3/7, where we fast from 1 to 3 days a week with a very limited intake of food and eat normally the other days. Intermittent fasting has a proven beneficial effect on blood sugar and insulin levels and consequently on insulin resistance.
All the guidelines outlined above are not only beneficial for the regulation of blood sugar and insulin. Regulated blood sugar levels also eliminate a series of mental conditions such as mood swings, restlessness, and depression. We must always strive for homeostasis in nutrition and health, just like nature - strive for stability and not fluctuation.
Barnosky et al. (2014) Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings
Penckofer et al (2012) Does Glycemic Variability Impact Mood and Quality of Life?