A1C: See Glycated hemoglobin test.

Acanthosis nigricans: Dark skin patches often found in children and adults who have prediabetes or diabetes; they are caused by insulin resistance.

ACE: See Atkins Carbohydrate Equilibrium.

ACE inhibitor drugs: Angiotensin-converting enzyme drugs used to treat hypertension,such as benazepril (Lotensin),captopril (Capoten), and lisinopril (Prinivil, Zestril).

Advanced glycated end products (AGEs): The result of glucose in the body binding with proteins; a major cause of blood vessel damage and other complications of diabetes.

Aerobic exercise: Exercise that increases your heart rate and the consumption of oxygen.

AGEs: See Advanced glycated end products.

AGR: See Atkins Glycemic Ranking.

Amino acids: The building blocks of protein; necessary for maintaining normal metabolism.

Anaerobic exercise: Also called resistance exercise. Any exercise that builds muscle strength.

Antioxidants: Substances that neutralize free radicals in the body. ARB drugs: Angiotensin receptor blocker drugs used to treat hypertension,such as irbesartan (Avapro),losartan (Cozaar),and valsartan (Diovan).

Atherosclerosis: Blood vessels clogged, narrowed, and hardened by deposits known as plaques.

Atkins Carbohydrate Equilibrium (ACE): The amount of Net Carbs in grams an individual can eat on a daily basis without gaining or losing weight.

Atkins Glycemic Ranking (AGR): A comparative ranking of carbohydrate-containing foods based on their glycemic index and glycemic load.

Beta-blocker drugs: Drugs such as metoprolol (Lopressor, Toprol), nadolol (Corgard), and propranolol (Inderal); most commonly used to treat hypertension.

Beta cells: Specialized cells in the pancreas that produce insulin. Biguanide drugs: Oral medications used to treat diabetes by reducing the amount of glucose produced by the liver and increasing insulin sensitivity. See also Metformin.

Blood lipids: Refers to total cholesterol, triglycerides, and HDL and LDL cholesterol circulating in the blood; the blood test that measures these factors.

Blood pressure: A measure of the force your bloodstream exerts against the walls of your arteries as your heart beats and rests.

Blood sugar: The amount of glucose in the bloodstream.

BMI: See Body mass index.

Body mass index (BMI): A measure of your body weight relative to your height, used to indicate weight ranges for underweight, normal weight, overweight, and obesity.

Calcium channel blockers: Drugs used to treat hypertension, such as amlopidine (Norvasc), diltiazam (Cardizem), felodipine (Plendil), nifedipine (Procardia), and verapamil (Covera).

Carbohydrate: A macronutrient found in plant foods that is broken down into glucose during the digestive process.

Cholesterol: A waxy substance necessary for many body functions,including making cell walls and hormones.

Coenzyme Q10 (CoQ10): An enzyme needed for normal production of energy in the mitochondria within the body’s cells.

CoQ10: See Coenzyme Q10.

C-peptide: A small protein normally produced as a by-product of insulin.The level of c-peptide in the blood is an indirect way of measuring insulin production.

C-reactive protein (CRP): A natural chemical in the blood used as a marker of inflammation.

CRP: See C-reactive protein.

Diabetes mellitus: Hyperglycemia due to an inability to use blood sugar for energy. See also Gestational diabetes; Type 1 diabetes;

Type 2 diabetes.

Diastolic blood pressure: The pressure in your blood vessels when the heart rests between beats; the second, lower number in a blood pressure reading.

Dietary reference intakes (DRI): Reference values for nutrient and energy intake for use in dietary plans and assessments.

Digestible fiber: Dietary fiber in the form of pectin and other substances. Also called soluble fiber.

Diuretics: Drugs that remove fluid from the body by causing increased urination.

DNA: The molecule that encodes genetic information in the nucleus of a cell and determines its structure, function, and behavior.

Endothelial dysfunction: Inflammation of the lining of the blood vessels, or endothelium.

Endothelium: The thin layer of cells lining all blood vessels. Essential fatty acids: Dietary fats necessary for your body,which must be obtained from food or supplements.

Fasting blood sugar (FBS): The amount of sugar (blood glucose) in the blood after a fast of 8 to 12 hours.

Fasting plasma glucose: See Fasting blood sugar.

Fat: Oily, organic compounds that don’t dissolve in water but do dissolve in other oils; also known as lipids. Fat is one of the three macronutrients in foods.

FBS: See Fasting blood sugar.

Fiber: The nondigestible parts of plant foods, such as cell walls.

Fibrinogen: A protein in the blood that is important for blood clotting. High levels can cause dangerous blood clots within blood vessels.

Free radicals: Harmful molecules created as part of normal metabo lism. Excess free radicals can cause damage to cells and cause oxidation.

Fructose: A simple sugar found in fruit and fruit juices.

Gestational diabetes: A form of diabetes that sometimes occurs during pregnancy.

GI: See Glycemic index.

GL: See Glycemic load.

Glitazone drugs: See Thiazolidinedione drugs.

Glucophage: See Metformin.

Glucose: A simple form of sugar burned as fuel by your body.

Glucose tolerance test (GTT): A test used to diagnose blood sugar abnormalities. Blood glucose is measured before and several times after drinking a high-glucose solution. The results show how the body uses blood sugar over a specific period of time.

Glycated hemoglobin test: A blood test that reflects blood sugar control over the past two to three months; also known as A1C.

Glycation: The process causing damage to protein in the body as a result of high levels of blood sugar.

Glycemic index (GI): A ranking of carbohydrate-containing foods based on the food’s impact on blood sugar relative to the same amount of glucose or white bread.

Glycemic load (GL): A ranking of carbohydrate-containing foods based on the food’s fiber content, glycemic index, and portion size.

Glycogen: Glucose stored in the liver and muscle tissues.

GTT: See Glucose tolerance test.

HDL cholesterol: High-density lipoprotein cholesterol. Also known as “good” cholesterol, a type of lipoprotein used to carry cholesterol back to the liver.

High blood pressure: See Hypertension.

Homocysteine: A by-product of metabolizing the amino acid methionine. High levels of homocysteine are associated with an increased risk of heart disease.

Hormone: A chemical such as insulin produced in a gland or organ and carried in the blood to another part of the body to stimulate a particular function.

Hydrogenated vegetable oil: See Trans fat. Hyperglycemia: Excessive sugar in the blood.

Hyperinsulinism: Excessive insulin in the blood.

Hypertension: A condition in which blood flows through blood vessels with more force than normal; also known as high blood pressure.

Hypoglycemia: Lower than normal blood sugar.

Hypothyroidism: A decrease in thyroid activity resulting in slowed metabolism. See also Thyroid gland.

Impaired fasting glucose: A fasting blood sugar level between 100 mg/dL and 125 mg/dL; also known as prediabetes.

Impaired glucose tolerance: Blood sugar that rises to between 140 mg/dL and 199 mg/dL two hours after the start of an oral glucose tolerance test or after a high-carb meal; also known as prediabetes.

Inflammation: Redness, swelling, heat, and dysfunction of a body part for a variety of reasons, including infection or injury.

Insulin: A hormone produced by the pancreas and used to carry glucose into the cells for energy.

Insulin resistance: The inability of cells to respond properly to insulin, the first stage of the metabolic syndrome.

Ketoacidosis: An emergency condition usually caused by extremely high blood sugar levels combined with a severe lack of insulin.This dangerous metabolic imbalance results in an abnormal acid state. If not immediately treated, this condition can lead to coma. Not to be confused with the perfectly safe production of ketones,resulting solely from following a low-carb dietary program.

Ketones: A by-product of fat that the body uses for energy.

Ketosis: Having ketones in the blood and urine,often as a result of following a low-carbohydrate eating plan; also known as benign dietary ketosis.

Lactose: A simple sugar found in milk and other dairy products.

LADA: See Latent autoimmune diabetes in adults.

Latent autoimmune diabetes in adults (LADA): A condition in which adults develop Type 1 diabetes.

LDL cholesterol: Low-density lipoprotein cholesterol. Also known as “bad” cholesterol; a lipoprotein found in the blood and used to carry cholesterol to the cells.

Lipid profile: See Blood lipids.

Lipids: A general term for fats in the body.

Lipoic acid. An antioxidant related to the B vitamins; used to treat peripheral neuropathy. Also known as alpha lipoic acid, or ALA.

Lipoprotein(a). A form of LDL cholesterol that has been shown to be an independent risk factor for heart disease.

Lp(a). See Lipoprotein(a).

Macronutrient. The dietary sources of calories and nutrients; specifically protein, fat, and carbohydrate.

Meglitinide drugs. Short-acting oral drugs for Type 2 diabetes, such as repaglinide (Prandin), that help the pancreas produce insulin immediately after meals.

Metabolic syndrome. A group of several signs or conditions, which include central obesity, hypertension, low HDL, high triglycerides, and high blood sugar. A major risk factor for heart disease, prediabetes, and diabetes. Also known as syndrome X.

Metformin. An oral drug (brand name Glucophage) used primarily for treating Type 2 diabetes; it reduces the amount of glucose produced by the liver and improves insulin sensitivity.

Microalbuminuria. Small amounts of protein in the urine.

Mitochondria. The portion of each cell that is responsible for energy production for that cell.

Mmol/L: Millimoles per liter, a unit of measure used outside the United States for indicating blood glucose levels and measurements of other specific substances in the blood.

Monounsaturated fat: Dietary fat with one missing hydrogen atom; found in foods such as olive oil, nuts, seeds, and avocados.

Morbid obesity: A BMI of 40 or more.

Nateglinide: An oral drug (brand name Starlix) for treating Type 2 diabetes; it helps the pancreas produce more insulin immediately after a meal.

Nephropathy: Kidney disease caused by hyperglycemia and/or hyper- tension.

Net Carbs: The carbohydrates in a whole food that have an impact on your blood sugar, represented by subtracting the fiber grams in the food from the total carbohydrate grams. In a low-carb product, sugar alcohols and glycerine are also deducted.

Neuropathy: Damage to the nerves, often caused by hyperglycemia. See also Peripheral neuropathy.

Neurotransmitters: Chemicals that transmit nerve impulses across synapses, or gaps, in the brain.

Nondigestible fiber: Dietary fiber consisting mostly of cellulose from plant walls; also called insoluble fiber.

Omega-3 fatty acids: A form of polyunsaturated dietary fat found in fish oil, flaxseed oil, and some other vegetable oils.

Omega-6 fatty acids: A form of polyunsaturated dietary fat found in many vegetable oils.

Oral glucose tolerance test: See Glucose tolerance test.

Oxidation: A chemical reaction that involves combining a substance with oxygen, similar to the process of metal rusting.

Pancreas: An organ found in the abdomen behind the stomach; the pancreas secretes the hormone insulin and other chemicals.

Partially hydrogenated vegetable oil: See Trans fat.

PCOS: See Polycystic ovary syndrome.

Peripheral neuropathy: Nerve damage affecting the feet, legs, and hands; causes pain, tingling, and numbness.

Polycystic ovary syndrome (PCOS): A hormonal imbalance in women; associated with enlarged or cystic ovaries, it causes irregular menstruation, infertility, weight gain, high blood sugar, and excessive hair growth.

Polyunsaturated fat: Dietary fat that is missing more than one hydrogen atom, such as corn and soybean oil.

Postprandial blood sugar: The amount of sugar (glucose) in the blood after a meal.

Prediabetes: Blood sugar levels that are higher than normal but not yet high enough to qualify as Type 2 diabetes.

Prehypertension: Elevated blood pressure that is between 120/80 and 139/89. The stage before hypertension.

Protein: Complex,intricately folded and coiled chains of amino acids. One of the three macronutrients found in foods.

Proteinuria: The presence of protein in the urine; an indication of possible kidney disease.

Prothrombotic state: Having blood that is more likely to form a dangerous clot within a blood vessel.

Reactive hypoglycemia: Also known as unstable blood sugar. A sharp drop in blood sugar following a sharp rise.

Retinopathy: Damage to the tiny blood vessels that nourish the retina, the light-sensitive area at the back of the eye.

Saturated fat: Dietary fat that contains as many hydrogen atoms as possible, such as palm and coconut oil. Usually solid at room temperature.

Statin drugs: Drugs such as atorvastatin (Lipitor), lovastatin (Mevacor), pravastatin (Pravachol), and simvastatin (Zocor) that block the action of HMG Co-A reductase and used to lower total and LDL cholesterol.

Sucrose: Table sugar; a two-part sugar consisting of glucose and fructose.

Sugar alcohols: Sweeteners such as manitol and sorbitol that have negligible impact on blood sugar in most people.

Sulfonylureas: A group of oral medications used to treat diabetes by helping the pancreas secrete more insulin; they include glimepiride (Amaryl), glipizide (Glucotrol), glyburide (Micronase), tolazamide (Tolinase), and tolbutamide (Orinase).

Syndrome X: See Metabolic syndrome.

Systolic pressure: Blood pressure when the heart contracts and pumps the blood; the first,higher number in a blood pressure reading.

Thiazolidinedione drugs: Oral drugs for treating Type 2 diabetes, including pioglitazone (Actos) and rosiglitazone (Avandia). These drugs improve insulin sensitivity.

Thyroid gland: A butterfly-shaped gland in the neck that secretes hormones crucial for regulating metabolism.

Trans fat: Partially hydrogenated or hydrogenated vegetable oil; a manufactured form of fat widely used in baked goods, fried foods, and snack foods.

Triglycerides: Fats that circulate in the bloodstream and are stored as body fat. Elevated levels are an independent risk factor for heart disease.

Type 1 diabetes: High blood sugar levels caused by a lack of insulin resulting from destruction of the beta cells in the pancreas.

Type 2 diabetes: High blood sugar caused by an inability to use insulin properly, and in later stages of the disease, an insufficiency of insulin.

TZD drugs: See Thiazolidinedione drugs.

Unsaturated fat: Dietary fat that has some unfilled hydrogen bonds; polyunsaturated and monounsaturated fats.

Unstable blood sugar: Blood sugar levels that rise and fall too much, too quickly, or both, as reflected in a more than 50-point drop in one hour on the GTT or a 100-point drop overall. Symptoms include headaches, irritability, mood swings, sweating, and heart pounding.

Very low density lipoprotein (VLDL): A form of LDL cholesterol associated with an increased risk of heart disease.

VLDL: See Very low density lipoprotein.

Waist-to-hip ratio: The size of your waist compared with the size of your hips. A high waist-to-hip ratio indicates abdominal obesity.