The evidence behind the Keto Diet
A ketogenic diet primarily consists of high fats, moderate protein and very low carbohydrate intake. The dietary macronutrients are divided into 55-60% fats, 30-35% protein and 5-10 % carbs. Specifically, a 200 kcal diet will contain 20-50 grams of carbs.
The ketogenic diet was firstly used in 1921 to treat epilepsy; it has been widely used to treat epilepsy until its popularity ceased with the introduction of antiepileptic agents. The resurgence of the ketogenic diet as a rapid weight loss regime is a relatively new concept the has shown to be quite effective, at least in the short run. Along with weight loss, other health parameters can improve on a ketogenic diet such as insulin resistance, high blood pressure and elevated cortisol and triglycerides.
How it works?
When the body is deprived of carbohydrates, which are the primary source of energy, due to reducing intake to less than 50 grams, insulin secretion is significantly reduced and the body enters a catabolic state, which means that the body needs to break down bigger molecules into smaller ones to produce energy. The metabolic process that comes in action when there is low carbohydrate availability is called ketogenesis. Ketogenesis provides an alternate source of energy in the form of ketone bodies that are produced from stored fats. Ketone bodies can be easily utilized as a form of energy by heart, muscle tissues and kidneys; they can also cross the blood-brain barrier to provide energy for the brain. Ketone bodies also decrease free radical damage and increase antioxidant capacity of the cells.
Why the keto diet is good for fat loss?
During ketogenesis, the stimulus for insulin secretion is also very low, reducing the stimulus for fat storage. Other hormonal changes that come from ketogenesis contribute to the increased breakdown of fats.
Following a ketogenic diet can be hard to maintain; possible symptoms from carb deprivation can last from days to weeks. The most common short-term side effects are nausea, vomiting, headache, fatigue, dizziness, insomnia, difficulty in exercise tolerance, and constipation. Along with these uncomfortable feelings, staying satisfied with the limited variety of foods available and being restricted from otherwise enjoyable foods like may present new challenges.
Long-term side effects include fatty liver and kidney stones.
What can we eat on a ketogenic diet?
Many versions of ketogenic diet exists, but all ban carb-rich foods. Foods that are excluded include refined and wholegrains like breads, cereals, pasta and rice, potatoes, corn and other starchy vegetables, beans, legumes and most fruits.
Most ketogenic diets include foods high in saturated fats like bacon and unsaturated fats such as nuts, seeds, avocado and oily fish.