Common Sense Carbohydrates
Keto Diet

Keto Diet: Common Sense Carbohydrates

We know that the three major nutrients, sugar (carbohydrates), protein, and fat, are the body’s energy sources, and they are also necessary to sustain life and ensure basic physiological functions of the body.

Although the keto diet has been popular for several years in many countries such as Europe and the United States and has helped countless people to lose weight successfully. However, because this diet severely limits carbohydrate intake, there are still many people who consider it unhealthy.

So far the science is inconclusive as to whether long-term keto is safe, however, at least short-term keto is not a problem. To better understand low-carb diets for weight loss (including keto), I feel it is important to talk about carbohydrates.

Does Our Body Need Carbohydrates?

There is a common misconception that our bodies, and especially our brains, cannot live without carbohydrates. In the field of weight loss, especially for low-carb diets like Atkins, South Beach, and keto, this is a topic that can be hotly debated.

The brain can use glucose, or “ketone bodies,” for energy. Dr. Jeff S. Wolek and Dr. Stephen D. Feeney, authors of The Art and Science of Low-Carbohydrate Performance, point out that ketone bodies are an important lipid fuel, especially for the brain, when carbohydrates in the diet are restricted.

In other words, when your body doesn’t get enough carbohydrates, it gives up glucose and turns to ketones for energy. Ketones are the product of fat burning. When you eat a lot of fat while limiting your carbohydrate intake, your body’s production of ketones increases. These ketone bodies are transported through the bloodstream to work in the muscles, brain, and various other organs.

Not only that, but compared to glucose, ketones allow the body and brain to have a higher level of energy. Although the body will still require small amounts of glucose (e.g. for red blood cells, kidney, and to a lesser extent brain function), this can be achieved entirely through gluconeogenesis.

Gluconeogenesis, also known as gluconeogenesis, is a metabolic process that converts non-carbohydrate nutrients (such as fats and proteins) into glucose, and it is done primarily in the liver. Gluconeogenesis ensures that our body has enough glucose available and that the body’s blood sugar is at a normal level.

Good and Bad Carbohydrates in the Keto Diet

In general, any food containing sugar or starch should be avoided, and the best indicator of “good” or “bad” carbohydrates is the glycemic load (GL) of the food.

  • Simply put, glycemic load refers to how food will raise the body’s blood sugar level when consumed.
  • Specifically, GL = the amount of carbohydrate in the food x the glycemic index (GI) of the food / 100.

The glycemic load (GL) value is the true reflection of how a food will affect blood sugar when eaten. Two examples:

  • Watermelon has a GI of 72, but a GL of 5.04, which is mostly water. A low GL indicates that a serving of watermelon doesn’t have much of an effect on your blood sugar.
  • Potatoes have a GI of 62, which is lower than watermelon, but because they contain 15 grams of carbohydrates per 100 grams, they have a GL of 9.3, which is higher than watermelon.

So unless you eat a large half of a watermelon in one sitting, it won’t have much effect on your blood sugar.

Good and Bad Carbohydrates in the Keto Diet

To Count Total or Net Carbohydrates

Generally, most of the fiber is not absorbed by the body, so it will not significantly affect blood sugar and ketosis levels. So when calculating the carbohydrate content of keto and low-carb diets, you can ignore the amount of fiber, so that what is left is net carbohydrate.

It is important to note that some countries in Europe and Australia will label their supplements directly as Net Carbohydrate (directly as Carbohydrate, not Total Carbohydrate), which is the amount of carbohydrate after the fiber is removed.

How Many Carbs to Eat at Each Meal to Avoid Blood Sugar Spikes?

Each person’s body is different and responds differently to carbohydrates. Some people cannot eat more than 10 grams of net carbohydrates per meal, while others may eat 50 grams of carbohydrates without their blood sugar peaking.

The best thing to do is pay attention to how you feel. If you feel lethargic and unrefreshed after a meal, you may be eating too much carbohydrate causing your blood sugar and insulin levels to rise too quickly. Blood sugar and insulin spikes have a direct effect on the brain, causing fatigue and drowsiness. What’s more, with fluctuations in blood sugar, you’ll soon be hungry again.

If you’re just starting a keto low-carb diet to lose weight, it’s best to avoid high-sugar, high-carb foods altogether and should focus on leafy green vegetables and low-carb fruits as your main source of carbohydrates.

How to Eat Carbs Before and After Exercise

If you are in the habit of exercising, you can eat some snacks before exercise, especially high-protein foods or drinks, which can increase both energy and athletic performance. As for whether to eat after exercise, it depends on your goals.

  • Weight loss: If the purpose of your exercise is to lose fat, then it is best not to eat carbohydrate-containing food after exercise, or a protein shake is enough.
  • Weight maintenance: Unless you are exercising for a long and strenuous period, you do not need to replenish your carbohydrates after exercise.
  • Gaining muscle: If you want to gain weight (muscle) or just want to get in shape, you can follow a standard keto diet and have a post-workout snack with carbs or protein, such as bananas, sweet potatoes, protein powder, etc.


Eating too many carbohydrates will convert to excess glucose in the body thus causing a spike in blood sugar and insulin while increasing fat storage. The purpose of a keto diet is to control blood sugar levels by limiting carbohydrate intake and encouraging the body to use ketone bodies for energy and improving fat-burning efficiency.