The Science Behind Ketogenic Diet
Would you believe that you can go on a diet eating bacon, lechon, and chicharon, and lose a significant amount of weight? Ketogenic diet, which is recently gaining popularity, has actually been around for almost a hundred years. This high fat, low carb diet which was originally intended to treat epilepsy is now used for weight loss and reduction of blood sugar level among diabetics. It works by putting the body in the state of “ketosis,” which utilizes fats instead of sugar as the source of energy, turning the body into a fat-burning machine. A typical “keto diet” would consist of 75% fats, 20% protein, and 5% carbohydrates.
Fat is not the culprit
One reason why the ketogenic diet has not quickly gained popularity as an effective weight loss intervention is probably its controversial high fat content. There are very few dieticians and physicians who would recommend this diet because of the belief that fats are linked to cardiovascular diseases. However, it has been proven by several scientific studies that a high fat diet is not bad for the body. In fact, a low carb/high fat diet was scientifically proven to decrease total cholesterol, triglyceride levels, LDL and VLDL levels and increase HDL levels.3,4,5,6,7 If fat is not the culprit, then why does it have such a bad rep? It turns out that the current widely accepted dietary guidelines were largely influenced by the sugar industry. In an article published by JAMA Internal Medicine, newly discovered documents revealed that, in the 1960s, a trade group called The Sugar Research Association paid Harvard scientists to produce “scientific” studies that minimize the association between sugar and heart disease and shift the blame on fat and cholesterol.8 Last year, The New York Times published an article revealing that the Coca-Cola company has paid scientists to downplay the link between sugar and obesity.9
What are the benefits of a ketogenic diet?
Many scientific studies have showed positive effects of ketogenic diet. These include decreased body mass index (BMI) and cardiovascular disease risk,3,10,11 improved blood sugar control and insulin sensitivity amongst diabetics,12,13,14 decreased LDL and increased HDL levels,3,4,5,6,7 increased mental performance,15,16 and reduced acne.17 It has also been proven to improve symptoms in patients with epilepsy,18 Parkinson’s disease,2 and polycystic ovarian syndrome (PCOS).19
How does ketogenic diet work?
When the body goes into a fasting state, it mobilizes the sugar stores in the liver and muscle. When the stores get depleted, fat stores are mobilized to form “ketones” which become the body’s new source of energy. In a ketogenic diet, the body thinks that it is in a fasting state due to the very low carbohydrate intake, so the metabolism shifts to ketosis and burns fat in the process.2
What are keto-friendly foods?
Only 20 to 50 grams of carbohydrates per day is allowed for the body to go into ketosis. Most keto advocates would recommend not taking any sources of carbohydrates at all so as to allocate the 20-50 g/day to “hidden carbs” found in foods such as vegetables and nuts. Table 1 lists down the foods that can and cannot be eaten in a ketogenic diet.
What are the side effects of ketogenic diet?
Some people have reported experiencing “keto flu” during the first couple of weeks of ketogenic diet. It may present as fatigue, headache, nausea, cramps, poor energy and mental function, increased hunger, sleep issues, digestive discomfort, and decreased exercise performance.
It is believed to be caused by the diuretic effect of a low carbohydrate diet, resulting in water and electrolyte losses. It is advised to drink lots of water and ensure adequate sodium, potassium, and magnesium intake.
What are the effects of ketogenic diet on exercise?
Studies have shown that ketogenic diet does not affect the aerobic endurance of athletes, which makes it suitable for endurance training.20 It may cause symptoms of hypoglycemia in those who do exercises that require bursts of energy and strength. However, there have been personal accounts that doing strength training on a ketogenic diet is possible. This can be achieved once the body is “keto-adapted” which takes around 3 to 4 weeks.