Introduction to the ketogenic diet

The ketogenic diet has gained a lot of popularity over the past few years, but it’s far from new. It was originally created in the 1920s as a treatment for childhood epilepsy. Before then, physicians knew fasting could help epilepsy and other conditions — but fasting is hard to sustain, so the ketogenic diet emerged as a more livable way to get similar effects. With the arrival of anticonvulsant medications, keto was largely set aside; for cases that medication couldn’t control, it was brought back.^1,2 In the past decade it has taken a prominent place in the health world — for epilepsy, weight loss, Parkinson’s, and beyond.³

Glucose vs. ketones for energy

Our bodies need energy to function, and most of the time they run on glucose. Glucose comes from digesting carbohydrates — sugars and starches broken down into glucose and released into the bloodstream, where it’s used or stored. To use or store it, we need insulin, a hormone made by beta cells in the pancreas that constantly check blood sugar to decide how much insulin to release.

The ketogenic diet is low in carbohydrates, moderate in protein, and high in fat. Instead of running on glucose, it prompts the body to run on ketones — chemicals the liver makes from fat. Once made, the liver sends ketones into the bloodstream to be used for fuel, which some researchers argue is a cleaner fuel for the body, especially the brain.⁴

Gluconeogenesis vs. ketogenesis

Gluconeogenesis is when the liver makes new glucose from non-sugar compounds — amino acids, lactate, and glycerol. The word literally means “the making (genesis) of new (neo) sugar (gluco).” When carbs are cut and sugar stores run low, the body will turn amino acids — from food and even its own muscle — into fuel.

Ketogenesis is when the body produces ketones (acetone, acetoacetate, and beta-hydroxybutyrate) from fatty acids. This happens when carbohydrate stores are low or fatty-acid levels rise.⁴

At first glance you might think we’d want only ketogenesis, and that gluconeogenesis works against the goal. But gluconeogenesis is genuinely helpful, especially during the transition from burning carbs to burning fat:

Conditions the ketogenic diet may help

Keto has improved the lives of people living with a number of challenging health conditions, including:

So why would one diet help such different conditions? Research shows the ketogenic diet can lower inflammation⁸ and may be a tool for managing pain.⁹ It inhibits activation of NF-κB, an inflammatory mediator involved in many inflammatory diseases.¹⁰ It can also improve mitochondrial function and offer a neuroprotective effect, though the mechanisms aren’t fully understood.¹¹ Because neuronal death is central to disorders like Alzheimer’s, this matters: research suggests keto can protect against neuron death, and in mice with ALS it improved motor-neuron counts and preserved motor function.¹¹ (If inflammation is your main concern, see chronic inflammation.)

Weight loss

Keto has also proven to be an effective way to lose weight. In ketosis, the body uses stored fat to make ketones for fuel — and research suggests some of the effect comes from simply feeling less hungry.¹² In one study of 83 patients with obesity who followed keto for 24 weeks, weight and body mass dropped significantly. As a bonus, HDL (good) cholesterol rose while LDL (bad) cholesterol fell, and triglycerides — a blood fat — also decreased.¹³ (Steady blood sugar is a big piece of this; see blood sugar and metabolic health.)

The benefits, in summary

In short, the ketogenic diet has real potential across a range of health goals:

Keto isn’t right for everyone, and how you do it matters — especially for women, whose hormones respond to carbohydrate intake differently. We’d love to help you figure out whether the ketogenic diet, alongside other supportive changes, is a good fit for you.