Written By: Mrs. Mayuri Mathur

Published On: 27 Jan, 2023 2:15 PM | Updated On: 15 May, 2024 4:32 PM

Ketogenic Diet: A Guide For Beginners

Diets have always been a topic of debate for decades. Unfortunately, only a few randomized clinical trials involving diets have addressed the combined question of weight loss and cardiovascular outcomes; one such is the ketogenic diet. The history of the ketogenic diet dates back to 1921 when Russel Wilder first used it to treat epilepsy. It was used as a therapeutic diet for pediatric epilepsy, for almost a decade, till the introduction of antiepileptic agents. The ketogenic diet is now emerging as a rapid weight loss formula and has shown its effectiveness, especially in the short run.

What is a Keto-diet?

The recently introduced ketogenic diet demands a strict limitation of carbohydrates while allowing liberal ingestion of fats (including saturated fats). It comprises dietary macronutrients as approximately 55% to 60% fat, 30% to 35% protein, and 5% to 10% carbohydrates. This diet is carried out for a minimum of 2 to 3 weeks up to 6 to 12 months. Close monitoring of renal functions while on a ketogenic diet is crucial, and the transition from a ketogenic diet to a standard diet should be gradual and well-controlled.

How does it work?

In the Ketogenic diet, the body is deprived of carbohydrates, and insulin secretion is significantly reduced. The body then enters a catabolic state, and two metabolic processes come into action in the low availability of carbohydrates in body tissues, namely gluconeogenesis and ketogenesis. 

When glucose availability drops further, the endogenous production of glucose becomes insufficient, and ketogenesis facilitates an alternate energy source in the form of ketone bodies. Ketone bodies replace glucose as a primary source of energy. During ketogenesis, low blood glucose feedback and less insulin secretion stimulus sharply reduce the stimulation for fat and glucose storage. Other hormonal changes may contribute to the increased fat breakdown resulting in fatty acids, later converted to primary ketone bodies that accumulate in the body as a ketogenic diet is sustained. This metabolic state is referred to as "nutritional ketosis." And the body remains in the ketotic state till the body is deprived of carbohydrates. 

The body utilizes these Ketone bodies for energy production by the heart, muscle tissue, and kidneys. Further, Ketone bodies can also cross the blood-brain barrier to provide an alternative energy source to the brain. Ketone bodies also reduce free radical damage and enhance antioxidant capacity.

This state is considered relatively safe, as ketone bodies are produced in small concentrations without altering blood pH. Furthermore, it is significantly different from ketoacidosis, where ketone bodies are produced in considerably larger concentrations, shifting blood ph to an acidotic state.

Benefits of Keto-diet

The ketogenic diet causes fast and pragmatic weight loss and favorable biomarker changes, like reduced serum hemoglobin A1c in patients with diabetes mellitus type 2.

A recent systemic review and meta-analysis of randomized controlled trials that compared the long-term effects (more than one year) of dietary interventions on weight loss observed the carbohydrate-restricted diet to be better than a low-fat diet in retaining an individual's BMR. 

A ketogenic diet initially renders a rapid weight loss of up to 10 lbs in 2 weeks or less. As a nutritional ketosis state sustains, hunger cramps subside, and an overall reduction in caloric intake helps to further weight loss. Interestingly, this diet plan largely spares lean body muscle.

Things to know before initiating the Ketogenic diet

The ketogenic diet has shown minor short-term side effects, including symptoms like nausea, vomiting, headache, fatigue, dizziness, insomnia, difficulty in exercise tolerance, and constipation, sometimes referred to as keto flu. These symptoms tend to resolve in a few days to a few weeks. Securing adequate fluid and electrolyte intake may ease these symptoms. Yet, long-term adverse effects include hepatic steatosis, hypoproteinemia, kidney stones, and vitamin and mineral deficiencies.

Better to avoid this diet in-

A ketogenic diet must be used cautiously for people with diabetes and people taking insulin or oral hypoglycemic agents, as they may experience severe hypoglycemia if the medications are not appropriately adjusted before initiating this diet. This diet is contraindicated in patients with pancreatitis, liver failure, disorders of fat metabolism, primary carnitine deficiency, carnitine palmitoyl transferase deficiency, carnitine translocase deficiency, porphyrias, or pyruvate kinase deficiency. 

From the clinician's view

Some healthcare workers recommend the ketogenic diet to counter the obesity epidemic. This diet may improve the clinical markers of disease risk in overweight individuals with metabolic syndrome, insulin resistance, and type-2 diabetes. It also enhances glucose control due to less glucose introduction and improved insulin sensitivity. In addition to reducing weight, especially truncal obesity and insulin resistance, this diet may also help improve blood pressure, glucose regulation, triglycerides, and HDL cholesterol levels. However, LDL cholesterol may increase on this diet. Various studies have also shown promising ketogenic diet results in neurological disorders like epilepsy, dementia, ALS, traumatic brain injury, acne, cancers, and metabolic disorders.

However, it also causes a substantial rise in low-density lipoprotein cholesterol levels, thus making many physicians hesitant to endorse it.