Food for thought: Analysing ketogenic diet, and myths of instant weight loss

“My main priority is long-term efficacy and safety,” says Hamdan. So, what exactly is a keto diet?

A keto diet is low in carbohydrates and high in fat. And the idea is simple. You switch the body’s fuel from sugar to fat. Our bodies normally utilise glucose (sugar) to produce energy. Whenever blood sugar depletes, for instance during and after sport, fasting, or starvation, the body shifts to fats as a source of energy. As with prolonged starvation, the keto diet puts the body in a state called ketosis — that’s when the body runs on fat. The name comes from “ketone bodies,” which are fat-derived compounds that the body relies on for fuel in the absence of sugars. When you limit sugar intake drastically, you force your body to use all the stored glycogen, a form of sugar stored in the liver. And when that sugar is used up, the body turns to burning fat for fuel and, after a period, enters the ketosis state. It can take 2-4 days to enter ketosis.

The Standard Keto Diet (SKD) is the most common. It limits your carbohydrates to less than 50 grams per day. That accounts for 10% of your total calories. The rest of your daily calories are split between 20% protein and 70% fat. Yes, that’s right — 70% fat. Other forms of the keto diet are more restrictive. For instance, carbohydrates can be limited to only 2% of your daily intake, your proteins down to 8%, and the rest is made up with 90% fat.

It’s generally considered healthy for an average adult to consume 225-323 grams (8-11 ounces) of carbohydrates per day. That’s 45-60% of your daily calorie intake. Notice the difference? To put it in perspective, a small banana has about 24 grams of carbs and 1 cup of cooked rice has 45 grams of carbs. If you exceed your daily allowed carbs, you risk losing the ketosis state, and the body will go back to burning sugar for fuel, which will effectively interrupt the diet.

The keto diet has been reported to be effective for weight loss, monitoring blood sugar in diabetic patients, and decreasing blood pressure and triglycerides (a type of fat). But it is unknown whether the weight loss is directly due to ketosis, or a result of people reducing their consumption of sugar and their overall calories, or the high levels of protein in the standard keto diet, which makes you feel sated (full).

When the body switches from sugar to fat as a source of energy, it can lead to flu-like symptoms known as “keto flu.” Symptoms include headache, nausea, and fatigue. Keto flu is harmless for most individuals, and people usually get over it within two weeks. Other side effects include muscle cramps and bad breath. Constipation is also a common side effect because the diet is poor in high fiber foods, such as whole grains, fruits and vegetables.

Cutting out fruits and vegetables can lead to vitamin and mineral deficiencies. Hamdan says she is concerned about long-term health issues, such as “an increased risk of liver disease, kidney stones, osteoporosis and gout.” “Ketone bodies are produced by the liver,” says Hamdan. “That can put pressure on the liver, which can cause liver disease. And a high protein content can sometimes affect our kidneys.”