Metabolic Health Terms, Explained Plainly

Over 102 straightforward definitions for the terms we use across our tools, articles, and podcast, without the jargon.

Jump to: A | B | C | D | E | F | G | H | I | K | L | M | N | O | P | R | S | T | U | V | W | Z

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A

A1C

A blood test that reflects your average blood glucose over roughly the past two to three months. Used alongside fasting glucose to assess blood sugar patterns over time.

Added Sugar

Sugar added to a food or drink during processing or preparation, separate from sugar naturally occurring in whole foods like fruit or dairy.

Adipose Tissue

Body fat tissue that stores energy and also produces hormones that influence metabolism and inflammation.

ALT (Alanine Aminotransferase)

A liver enzyme measured in standard blood panels. Elevated levels can be a marker of liver stress, including from fatty liver.

Apolipoprotein B (ApoB)

A protein found on LDL and other particles that carry cholesterol. Some clinicians use ApoB alongside LDL for a fuller picture of cardiovascular risk.

Arterial Stiffness

A measure of how flexible your blood vessels are. Stiffer arteries are associated with higher blood pressure and cardiovascular strain over time.

AST (Aspartate Aminotransferase)

A liver enzyme often measured alongside ALT. Elevated levels can indicate liver or muscle stress.

Atherosclerosis

The gradual buildup of plaque inside artery walls, which can narrow blood vessels over time and is linked to cardiovascular risk factors like LDL and blood pressure.

B

Basal Metabolic Rate (BMR)

The number of calories your body needs at complete rest just to maintain basic functions like breathing and circulation.

Beta Cells

Cells in the pancreas responsible for producing insulin in response to blood sugar levels.

Blood Pressure

The force of blood pushing against artery walls, expressed as two numbers: systolic (pressure during a heartbeat) over diastolic (pressure between beats).

BMI (Body Mass Index)

A calculation using height and weight to estimate body fat category. It's a screening tool, not a diagnosis, since it doesn't distinguish muscle from fat.

C

C-Peptide

A byproduct created when the body produces insulin. Measuring it can help estimate how much insulin your own pancreas is making.

C-Reactive Protein (CRP)

A marker of inflammation in the body, measured through a blood test. Chronically elevated CRP is one signal considered as part of Inflammatory Load.

Cardiovascular Risk

An estimate of your likelihood of developing heart or blood vessel disease, typically based on a combination of factors like cholesterol, blood pressure, age, and lifestyle.

Circadian Rhythm

Your body's internal 24-hour clock, which influences sleep, hormone release, and metabolic processes including overnight glucose regulation.

Complex Carbohydrates

Carbohydrates made of longer chains of sugar molecules, like whole grains and legumes, which are typically digested more slowly than refined carbohydrates.

Continuous Glucose Monitor (CGM)

A wearable device that tracks glucose levels throughout the day and night, offering a more complete picture than periodic finger-stick readings.

Cortisol

A hormone released in response to stress that also plays a role in regulating blood sugar, particularly overnight and in the early morning.

Creatinine

A waste product filtered by the kidneys, measured in blood tests to help estimate kidney function.

Cytokines

Small proteins released by cells that help regulate immune response and inflammation throughout the body.

D

Dawn Phenomenon

A natural rise in blood sugar that can happen in the early morning as the body releases hormones to help you wake up, sometimes making fasting glucose readings higher than expected.

Diastolic Pressure

The bottom number in a blood pressure reading, representing the pressure in your arteries between heartbeats.

E

eGFR (Estimated Glomerular Filtration Rate)

A calculation used to estimate how well your kidneys are filtering waste from your blood.

Electrolytes

Minerals like sodium, potassium, and magnesium that carry an electrical charge and support nerve, muscle, and fluid balance functions in the body.

F

Fasting

A period of not eating, often used before certain lab tests to get a baseline reading of glucose or lipids without recent food intake affecting results.

Fasting Glucose

A blood sugar reading taken after not eating for at least 8 hours, typically first thing in the morning. It's one snapshot rather than a full picture on its own.

Fatty Liver (MASLD)

A condition where excess fat builds up in the liver, often related to metabolic factors like insulin resistance and elevated triglycerides.

Fiber

A type of carbohydrate the body can't fully digest, which supports digestive health and can help moderate the glucose response to a meal.

Four Loads Framework

Our framework organizing metabolic health into four connected areas: Glucose Load, Storage Load, Regulatory Load, and Inflammatory Load, instead of treating each lab number as a separate issue.

Free Radicals

Unstable molecules that can damage cells when present in excess, contributing to oxidative stress.

G

Ghrelin

A hormone often called the "hunger hormone" because it signals to your brain that it's time to eat.

Glucagon

A hormone that raises blood sugar by signaling the liver to release stored glucose, working opposite to insulin.

Gluconeogenesis

The process by which your liver creates new glucose from non-carbohydrate sources, which can influence fasting blood sugar, especially overnight.

Glucose Load

One of our Four Loads. Refers to how your body handles the sugar and carbohydrates you eat, and how steady your levels stay between meals.

Glycemic Index

A ranking of how quickly a carbohydrate-containing food raises blood sugar compared to a reference food, usually pure glucose.

Glycemic Load

A measure that accounts for both the glycemic index of a food and the amount of carbohydrate in a typical serving, giving a fuller picture than glycemic index alone.

Glycemic Response

How much and how quickly your blood sugar rises after eating a particular food or meal.

Glycogen

The stored form of glucose kept in your liver and muscles, used as a reserve energy source between meals and during activity.

Growth Hormone

A hormone released primarily during sleep that supports tissue repair and can also influence blood sugar regulation.

H

HDL Cholesterol

Often called "good" cholesterol. HDL helps transport cholesterol away from your arteries, and higher levels are generally considered favorable in the context of your full lipid panel.

Hemoglobin

The protein in red blood cells that carries oxygen. Glucose can attach to hemoglobin over time, which is the basis for the A1C test.

HOMA-IR

A calculation using fasting glucose and fasting insulin to estimate insulin resistance. It's a research and screening tool, not a diagnosis on its own.

HPA Axis

Short for hypothalamic-pituitary-adrenal axis, the system that governs your body's stress response, including cortisol release.

hs-CRP (High-Sensitivity CRP)

A more sensitive version of the standard CRP test, able to detect lower levels of inflammation, sometimes used in cardiovascular risk assessment.

Hyperglycemia

The medical term for higher-than-normal blood sugar levels.

Hypertension

The medical term for persistently elevated blood pressure.

Hypoglycemia

The medical term for lower-than-normal blood sugar levels, which can cause symptoms like shakiness, sweating, or confusion.

I

Inflammatory Load

One of our Four Loads. The background strain from chronic low-grade inflammation that can influence how the other three Loads behave over time.

Insoluble Fiber

A type of fiber that doesn't dissolve in water and adds bulk to stool, supporting regular digestion.

Insulin

A hormone produced by the pancreas that helps cells absorb glucose from the bloodstream for energy or storage.

Insulin Resistance

A state where the body's cells respond less effectively to insulin, requiring the pancreas to produce more of it to manage blood sugar.

Insulin Sensitivity

The opposite of insulin resistance: how effectively your cells respond to insulin. Higher sensitivity generally means better blood sugar regulation.

Intermittent Fasting

An eating pattern that cycles between periods of eating and fasting, sometimes used as one tool among many for metabolic health.

K

Ketones

Molecules produced by the liver from fat when carbohydrate intake is very low, used as an alternative fuel source by the body.

Ketosis

A metabolic state in which the body relies more heavily on ketones for fuel, typically reached through very low carbohydrate intake.

Kidney Function

How effectively your kidneys filter waste and excess fluid from your blood, often assessed through markers like creatinine and eGFR.

L

LDL Cholesterol

Often called "bad" cholesterol. Elevated LDL is one factor considered in cardiovascular risk, typically alongside HDL, triglycerides, and other markers.

Leptin

A hormone produced by fat cells that signals fullness to the brain, helping regulate appetite and energy balance.

Lipid Panel

A blood test measuring cholesterol markers, including total cholesterol, HDL, LDL, and triglycerides.

Lipoprotein(a)

A genetically influenced type of cholesterol particle that some clinicians test as an additional cardiovascular risk marker.

Liver Enzymes

Proteins like ALT and AST measured in blood tests to help assess liver health and detect signs of liver stress.

M

Macronutrients

The three main categories of nutrients that provide calories: carbohydrates, protein, and fat.

Metabolic Flexibility

Your body's ability to efficiently switch between burning carbohydrates and fat for fuel depending on availability and demand.

Metabolic Load

The overall strain placed on your metabolic systems from the combination of Glucose, Storage, Regulatory, and Inflammatory Loads.

Metabolic Syndrome

A cluster of related factors, including waist size, blood pressure, triglycerides, and blood sugar, that tend to move together. Having several outside a healthy range at once is associated with higher long-term health risk.

Micronutrients

Vitamins and minerals the body needs in smaller amounts to support various functions, including metabolic processes.

N

NEAT (Non-Exercise Activity Thermogenesis)

The energy you burn through everyday movement that isn't structured exercise, like walking, fidgeting, or standing.

Net Carbs

Total carbohydrates in a food minus fiber (and sometimes sugar alcohols), used as an estimate of the carbs that meaningfully affect blood sugar.

Non-HDL Cholesterol

Total cholesterol minus HDL, capturing all the potentially artery-clogging cholesterol particles in one number.

O

Omega-3 Fatty Acids

A type of unsaturated fat found in fish and certain plant sources, often studied in relation to cardiovascular and inflammatory markers.

Oxidative Stress

An imbalance between free radicals and the body's ability to neutralize them, which can contribute to cellular damage over time.

P

Pancreas

The organ responsible for producing insulin and glucagon, the two primary hormones that regulate blood sugar.

Postprandial Glucose

Blood sugar measured after eating, typically one to two hours after a meal, used to assess how your body handles that meal.

Prediabetes

A term describing blood sugar levels that are higher than typical but not yet in the range associated with type 2 diabetes.

Pulse Pressure

The difference between your systolic and diastolic blood pressure numbers, sometimes used as an additional marker of arterial health.

R

Refined Carbohydrates

Carbohydrates that have been processed to remove fiber and nutrients, such as white flour and white sugar, which are typically digested quickly.

Regulatory Load

One of our Four Loads. The systems, including blood pressure regulation, that keep several key markers in a healthy range day to day.

Resistance Training

Exercise that works muscles against resistance, such as weights or bodyweight, which can support metabolic health alongside other lifestyle factors.

Resting Metabolic Rate (RMR)

The number of calories your body burns at rest, similar to BMR but typically measured under slightly less strict conditions.

S

Saturated Fat

A type of fat found in animal products and some plant oils, one of several dietary fat categories considered when assessing overall diet quality.

Sleep Apnea

A condition involving repeated interruptions in breathing during sleep, associated with disrupted rest and potential effects on blood pressure and glucose regulation.

Sleep Debt

The cumulative effect of not getting enough sleep over time, which can affect appetite hormones, stress hormones, and glucose regulation.

Soluble Fiber

A type of fiber that dissolves in water and forms a gel-like substance, which can help moderate blood sugar and cholesterol absorption.

Storage Load

One of our Four Loads. How your body stores and accesses energy, and how that relates to waistline and weight over time.

Stress Response

Your body's physiological reaction to perceived threats or pressure, involving hormones like cortisol and adrenaline that can influence blood sugar and blood pressure.

Subcutaneous Fat

Fat stored just beneath the skin, distinct from visceral fat, which surrounds internal organs.

Systolic Pressure

The top number in a blood pressure reading, representing the pressure in your arteries during a heartbeat.

T

Thermogenesis

The process of generating heat in the body, which burns calories and is one component of total daily energy expenditure.

Total Cholesterol

The sum of all cholesterol types in your blood, including HDL, LDL, and a portion of your triglycerides, from a standard lipid panel.

Trans Fat

A type of fat, often artificially created, historically used in processed foods and now understood to raise cardiovascular risk more than most other fat types.

Triglycerides

A type of fat found in your blood, measured as part of a standard lipid panel. Elevated triglycerides are one of the factors considered in metabolic syndrome.

Triglyceride-to-HDL Ratio

A quick ratio calculated from a standard lipid panel, sometimes used as an additional marker of metabolic and cardiovascular risk.

TyG Index

The Triglyceride-Glucose Index, a calculation combining fasting triglycerides and fasting glucose, used as a research-backed estimate of insulin resistance.

Type 2 Diabetes

A condition marked by persistently elevated blood sugar, typically related to insulin resistance and reduced insulin production over time.

U

Unsaturated Fat

A category of dietary fat, including monounsaturated and polyunsaturated fats, generally found in plant oils, nuts, and fish.

V

Visceral Fat

Fat stored around internal organs in the abdominal area. Higher levels are associated with increased metabolic and cardiovascular risk compared to subcutaneous fat.

VLDL (Very-Low-Density Lipoprotein)

A type of cholesterol particle that primarily carries triglycerides through the bloodstream.

W

Waist-to-Height Ratio

Your waist circumference divided by your height. A simple screening measurement related to Storage Load that's easy to track over time without special equipment.

Waist-to-Hip Ratio

Your waist circumference divided by your hip circumference, another simple screening measurement related to fat distribution.

Waist Circumference

A simple measurement around your midsection, used as one factor in assessing metabolic syndrome and Storage Load.

Z

Zone 2 Cardio

A moderate-intensity exercise zone, often described as a pace where you could hold a conversation, sometimes discussed in relation to metabolic flexibility and fat utilization.