Carb fasting glossary
15 terms, one or two sentences each. Every definition links back to the page where it matters.
- C Carb cycling
- Rotating high, medium, and low carbohydrate days, usually timed around training and tracked with macros. Carb fasting is its simpler, two-state cousin.
- Continuous glucose monitor (CGM)
- A small wearable sensor that tracks blood glucose in real time. Useful for seeing how specific foods and fast days affect your curve.
- F Fasting insulin / HOMA-IR
- A fasting blood measure (and a derived index) used to estimate insulin resistance. Often improves when carbohydrate exposure drops.
- Fat switch
- A plain name for the metabolic tipping point. When carbs are scarce and glycogen runs low, the body flips from storing fat to burning it.
- Fat-adapted
- A state in which the body uses stored and dietary fat for fuel efficiently. Reached over days to weeks of repeated low-carb periods.
- G Glycemic variability
- How much blood sugar swings up and down across a day. Steadier glucose usually means steadier energy and fewer cravings.
- Glycogen
- The stored form of carbohydrate, held in the liver and muscles. When glycogen is full the body has little reason to burn fat; running it down on fast days is what flips the fat switch.
- H HbA1c
- A blood test that reflects average blood sugar over roughly three months. A core measure for prediabetes and diabetes.
- I Insulin
- The hormone that moves glucose out of the blood and into cells. Frequent carb intake keeps insulin elevated, which favors storing fat over burning it.
- Insulin resistance
- When cells respond poorly to insulin, so the body makes more of it. Linked to weight gain and a step on the road to prediabetes and type 2 diabetes.
- K Ketones
- Fat-derived molecules the liver produces when carbohydrate is scarce. The brain and muscles can run on them.
- Ketosis (nutritional)
- A normal metabolic state in which, with carbohydrate low, the liver makes ketones from fat. Distinct from diabetic ketoacidosis, which is dangerous.
- M Metabolic flexibility
- The ability to switch fuel sources: burning carbohydrate when it is available and fat when it is not. Rebuilding it is the whole point of carb fasting.
- P Postprandial glucose
- Blood sugar measured after a meal. Large post-meal spikes drive the insulin surge, crash, and cravings that carb fasting is designed to blunt.
- T Time-restricted eating
- Limiting the hours of the day in which you eat, for example an 8-hour window. It changes when you eat; carb fasting changes what you eat on certain days.
Want the bigger picture? Start with what carb fasting is or read the science.
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