What is the Ketogenic Diet? Health benefits and side effects

The ketogenic diet gained massive popularity over the past few years due to its effects on weight loss and other health benefits. In fact, keto is the most popular diet in the United States by a large margin.

The primary concept behind this diet is to limit your carbohydrate intake to 20–50 grams per day, which pushes your body into a state known as ketosis. In general, it takes around 10–15 days to get into this metabolic state.

In this article, we will briefly define ketosis and see how this metabolic state helps you lose weight.

What is ketosis?

Ketosis refers to a metabolic state where the liver converts fatty acids to generate energy. This reaction produces ketone bodies as metabolic byproducts, which is where the terminology came from.

To reach this state, you need to meet two conditions:

  • Your intake of sugar needs to be less than 50 grams per day.
  • The sugar stored in the liver and muscles needs to get depleted.

Once the body starts using fatty acids to produce energy, you will experience substantial weight loss and other health benefits.

Note that the initial weight loss (during the 1–2 weeks) mainly consists of fluids, and therefore, you should not expect to lose the same number of pounds every week.

What are the side effects of the keto diet?

In general, the ketogenic diet is safe for most people. However, some people report side effects that mainly occur during the first week.

The reason behind this is simple:

When you suddenly deprive your body of sugar, it will violently react to that. Over time, the liver and cells all over your body get used to the carbohydrate-deficient state, and symptoms typically subside.

In rare cases, hypoglycemia (i.e., low blood sugar) can develop, manifesting as cold extremities, confusion, and trembling.

If you experience any severe symptoms when starting the ketogenic diet, it might be safer to consult with your primary care physician.

The keto flu

The keto flu is the most commonly reported adverse effect of the ketogenic diet. It describes a variety of signs and symptoms that resemble the seasonal flu.

The signs and symptoms of the keto flu include:

  • Fever
  • Headache
  • Chills
  • Nausea
  • Vomiting
  • Fatigue
  • Arthralgia (joint pain)
  • Myalgia (muscle pain)

Unfortunately, many people abandon the keto diet after experiencing the keto flu, which is unnecessary since the symptoms of the keto flu quickly subside. Moreover, adequate hydration and electrolyte supplements can prevent the keto flu altogether.

According to studies, the keto flu gets triggered by the abrupt exclusion of carbs from your diet.

Besides these mild side effects, the ketogenic diet does not cause any health problems.


The ketogenic diet is one of the most effective ways to lose weight. It also offers other health benefits that involve the heart, brain, and digestive tract.