Ketones, also known as “ketone bodies”, are energy molecules created by the liver from the breakdown of fats. Your body makes ketones when you don’t have access to carbs or enough glucose stores (glycogen).
Although most people run on carbohydrates (glucose), studies are now showing that burning fats (ketones) for energy is the healthier alternative.
Your body can burn two fuels for energy: carbs or fat. Carbs are converted into glucose whereas fats are converted into ketones by the liver.
The process of turning fat into ketones is called ketogenesis.
Whenever you stop giving your body a constant supply of carbs and glycogen stores are emptied — such as during a ketogenic diet, fasting, or intense exercise — your body seeks out stored or dietary fat to turn it into ketones for energy.
Why Your Body Favors Ketones Over Glucose for Energy
Adenosine Triphosphate (ATP) is your body’s energy currency. The more ATP your cells make, the more energy you have to power through the day.
Research shows that ketone-derived ATP generates more energy than glucose-derived ATP, which means running on ketones is better for your energy levels.
Additionally, using fats as energy stabilizes your insulin and blood sugar. This helps decrease inflammation and regulate hormonal function, including the hormones leptin and ghrelin, which control your appetite.
When you start using ketones, you’ll notice you no longer feel hungry every two or three hours like you usually would on a carbohydrate-heavy diet.
Other Benefits of Running On Ketones
Studies show a wide range of benefits of running on ketones, such as:
- Improved mental functioning. BHB (Beta-hydroxybutyrate) is your brain’s preferred ketone body for energy. Studies have shown that ketone bodies (mainly BHB) help improve cognitive performance as well as reduce symptoms of Alzheimer’s and Parkinson’s disease.
- Increased satiety. When running on ketones, you feel satiated for hours thanks to the regulation of the hormones ghrelin and leptin.
- Higher energy levels. Each gram of fat contains 9 calories, while protein and carbs only provide 4 calories per gram each, so you enjoy more energy from a high fat diet. In addition, ketone-derived ATP provides more energy to your muscles than glucose-derived ATP. This means endurance athletes like marathon runners can benefit from using ketones as their main source of energy.
- Longevity. The process of making ketones increases the production of antioxidants and triggers anti inflammatory genes, which contributes to a healthier and longer lifespan.
- Better workout performance. When you exercise, your muscles absorb ketones faster, and ketones boost your muscle performance and increase fat loss.
- Blood glucose control. Using ketones for energy instead of glucose keeps your blood sugar in check and increases insulin sensitivity, which improves your metabolic function.
- Disease prevention. Thanks to the antioxidant and antiinflammatory effects of ketone production, your cells have more protection against neurodegenerative and metabolic diseases.
Ketones Are The Preferred Source of Fuel For Your Body
The research is clear on the efficacy of using ketones as the primary source of energy for your body. Running on ketones leads to increased fat loss, improved mental clarity, better mood, higher energy levels, a longer lifespan, and better workout performance.
And even though the studies on ketones and the keto diet are recent, using ketones is nothing new. Our ancestors depended on ketones for thousands of years and babies are literally born in ketosis due to breast milk’s fatty composition.
We evolved to run on ketones, and that’s why ketosis has so many health benefits.
Using ketones is like putting premium fuel into your car instead of regular gas. They are the alternative fuel that your body runs better on.
If you’re currently on a carb-based diet and you’re not feeling your best, you can benefit from switching to a better, cleaner fuel.
Ketones transform how your metabolism works so you can optimize your health and well-being, as well as prevent chronic diseases like type II diabetes, Alzheimer’s, and the metabolic syndrome.
BHB VS. GLUCOSE AS FUEL
If you’re curious to know exactly how BHB compares to glucose in terms of energy, here’s a breakdown of their:
- Energy Efficiency
- Energy Yield
Creating energy generates harmful by-products called free radicals, or oxidants. These molecules can damage cells and DNA, and they’re inevitable.
During the production of ATP, the oxidants O2∙− and H2O2 are leaked. These are “tamer” free radicals that can be easily countered with antioxidants.
However, under the wrong circumstances, they have the potential to run wild and turn into the most damaging free radicals: reactive nitrogen species (RNS) and hydroxyl radical (∙OH), which are responsible for most oxidative damage.
Therefore, it’s necessary to minimize free radicals during energy production and optimize antioxidants.
The fuel your body uses and the resources they consume to create ATP influences how many free radicals are created and suppressed.
The fewer free radicals a fuel creates, the more efficient it is.
Glucose goes through a slightly longer process than BHB before entering the Krebs cycle.
Through glycolysis, glucose turns into pyruvate, and then pyruvate is turned into acetyl-CoA, which can enter the Krebs cycle.
This path from glucose > pyruvate > acetyl-CoA eats up significant resources.
One glucose molecule consumes 4 NAD+ molecules, which turn into 4 NADH.
The ratio of NAD+/NADH matters because it regulates oxidant and antioxidant activity:
- NAD+ is the “good” molecule. It protects against oxidative stress, especially the oxidant H2O2, and improves autophagy (cleaning up damage cells). NAD+ is consumed as fuel for chemical reactions (like ATP production) and turns into NADH.
- NADH is also necessary, mainly to produce ATP, but it doesn’t protect against damage. When there’s more NADH than NAD+, more free radicals are produced and helpful enzymes are inhibited.
In other words, the ratio of NAD+/ NADH should stay high. Low NAD+ causes serious oxidative damage.
Because glucose consumes 4 NAD+ molecules from the get-go, it tips the scale towards more NADH, which can cause more oxidative damage.
BHB skips glycolysis. It only has to convert back to AcAc and then to acetyl-CoA before entering the Krebs cycle, a process that uses up half the resources as glucose.
One BHB molecule consumes only 2 NAD+ molecules, which turn into 2 NADH.
This means BHB is more efficient than glucose and protects the NAD+/NADH ratio.
In fact, research shows BHB not only preserves but increases the NAD+/NADH ratio, which can:
- Protect against oxidative stress and oxidants created during energy production
- Support mitochondrial function and biogenesis
- Provide anti-aging and longevity effects
- Increase the amount of free NAD+ than can be used for optimal gene expression
BHB also reduces free radicals through protective proteins that only activate when your body runs on ketones:
- UCP: Fats accelerate the activity of the UCP protein. UCP kills the free radicals that leak during the creation of energy, preventing oxidative damage in the mitochondria.
- SIRT3: When your body switches from glucose to fats, a protein called Sirtuin 3 (SIRT3) increases. It activates a powerful antioxidant called of MnSOD and other mitochondrial antioxidant systems to keep oxidants low during energy creation. It also stabilizes the FOXO genes, which protect against oxidation.
Using BHB for fuel is more efficient than using glucose because it consumes less NAD+ molecules, increasing the NAD+/NADH ratio, which prevents oxidative damage and promotes longevity. It also fights the damage of inevitable free radicals by activating powerful antioxidants, which glucose doesn’t do.
The energy yield is measured by two things:
- Number of ATP molecules created per molecule of BHB or glucose
- Usable energy from each ATP molecule
Each molecule of glucose and BHB creates different amounts of ATP, which carries usable energy to your cells.
When ATP releases this energy inside your cells, it’s called ATP hydrolysis. The amount of energy released can be measured in kilocalories, through an equation called the change in Gibbs free energy (ΔG).
In this context, ΔG represents the kilocalories released by each individual molecule of ATP.
Energy Yield of Glucose
One molecule of glucose makes about 30-34 molecules of ATP. It was widely believed the yield was 36-38, but newer sources find that was an overestimation.
The official change in free energy (∆G) is -7.3 kcal/mol.
This means each molecule of ATP generates about 7.3 kilocalories.
The total energy released by one glucose molecule would be:
34 ATP*7.3 kilocalories = 248 kilocalories.
Energy Yield of BHB
One molecule of BHB makes around 21.5 molecules of ATP. This is less than glucose, but remember it’s more efficient and creates fewer free radicals in the process.
In addition, ketone-made ATP releases a higher number of usable kilocalories (∆G). There is no official ∆G for this ATP, but one of the first studies on the topic found a change in free energy of -13 kcal/mol, which was confirmed by follow up studies.
This means each ATP molecule generates 13 kilocalories, almost double than ATP from glucose.
The total energy released by one BHB molecule would be:
21.5 ATP*13 kilocalories = 279 kilocalories.
Glucose yields more ATP molecules, but the total energy released by each ATP is lower than BHB.
BHB creates fewer ATP molecules, but it’s cleaner and releases more total energy per ATP molecule.