Gluconeogenesis Calculator
Estimate Daily Gluconeogenesis Rate
A scientifically accurate tool to calculate how much glucose your body produces via gluconeogenesis during fasting or low-carb states.
Your Estimated Daily Gluconeogenesis
About the Gluconeogenesis Calculator
The Gluconeogenesis Calculator is a research-backed online tool designed to estimate how much glucose your body produces through Gluconeogenesis when dietary carbohydrate intake is low or during fasting. This process is essential for maintaining blood glucose levels and supporting brain function in the absence of dietary carbs.
What is Gluconeogenesis?
Gluconeogenesis (GNG) is the metabolic pathway that synthesizes glucose from non-carbohydrate precursors such as lactate, glycerol, and amino acids (primarily alanine and glutamine). It occurs mainly in the liver and to a lesser extent in the kidneys. This pathway becomes critically important during prolonged fasting, starvation, ketogenic diets, and intense exercise when glycogen stores are depleted.
Scientific Foundation: The calculations in this Gluconeogenesis Calculator are based on peer-reviewed studies including:
- Cahill GF Jr. (2006) – Fuel metabolism in starvation
- Owen OE et al. (1969, 2005) – Brain glucose uptake in prolonged fasting
- Féry F et al. (2002) – Quantitative contributions of glycerol and alanine
- Landau BR et al. (1996) – Glycerol as a gluconeogenic precursor
- Jahoor F et al. (1990) – Alanine and glutamine turnover rates
Why is Gluconeogenesis Important?
Even on a zero-carb or ketogenic diet, the human body still requires approximately 100–130 grams of glucose per day to fuel:
- Red blood cells (no mitochondria)
- Parts of the brain (though ketones can replace ~60–70%)
- Renal medulla and testes
- Anaerobic glycolysis during intense exercise
When dietary carbohydrates are insufficient, gluconeogenesis ramps up to meet this demand, primarily using:
- Lactate (Cori cycle) – ~40–50%
- Glycerol (from lipolysis) – ~15–25%
- Amino acids (mainly alanine & glutamine) – ~25–40%
When Should You Use This Gluconeogenesis Calculator?
Use this tool if you are:
- Fasting (intermittent or extended)
- Following a ketogenic or carnivore diet
- Curious about protein requirements to avoid excess gluconeogenesis
- Experiencing fatigue on very low-carb diets
- Planning endurance training in a fasted state
How the Calculator Works (Scientific Methodology)
The algorithm combines:
- Basal glucose requirement: ~100 g/day in early fasting, dropping to ~70–80 g/day after 3–4 weeks as ketones rise (Owen 2005).
- Body weight factor: Larger individuals have higher absolute higher turnover.
- Time factor: Gluconeogenesis peaks around 16–24h of fasting and then stabilizes.
- Activity multiplier: Exercise increases lactate recycling and glucose demand.
- Diet state: Strict ketosis reduces obligatory glucose needs.
Interpreting Your Results
Typical ranges:
| State | Estimated GNG (g/day) |
|---|---|
| 12–16h fast | 80 – 110 g |
| 24–72h fast | 100 – 140 g |
| Prolonged fasting (>7 days) | 70 – 90 g |
| Strict keto + exercise | 90 – 160 g |
Protein Sparing and the “Myth” of Excess Protein Turning into Glucose
Once you are keto-adapted (>2–4 weeks), excess dietary protein does not significantly increase gluconeogenesis due to downregulation of enzymes and hormonal control (insulin, glucagon, cortisol). The body preferentially uses amino acids for protein synthesis and only converts what is absolutely needed.
Limitations of This Calculator
This tool provides an estimate based on population averages. Individual variation exists due to genetics, muscle mass, hormone status (e.g., cortisol, thyroid), and degree of keto-adaptation.
Conclusion
The Gluconeogenesis Calculator gives you evidence-based insight into one of the most fascinating adaptations of human metabolism. Understanding your personal glucose production helps optimize fasting windows, protein intake, and performance on low-carb lifestyles.
Developed with ❤ by Agri Care Hub
