ISSA Nutritionist key terms

The energy, in calories, that the body uses at complete rest to sustain basic functions such as breathing, circulation, and cell repair. It typically accounts for the largest share of daily energy expenditure.

A measured estimate of calories burned while awake, still, and at rest, usually slightly higher than BMR because it includes some low-level activity. Coaches often use RMR to estimate a client's baseline calorie needs.

The sum of all calories a person burns in a day, combining resting metabolism, physical activity, and the energy cost of digesting food. It is the reference point for setting calorie targets for weight loss, maintenance, or gain.

The calories the body spends digesting, absorbing, and processing nutrients, roughly a small percentage of total intake. Protein has a higher TEF than carbohydrate or fat, which is one reason protein-rich diets can modestly raise daily calorie burn.

The relationship between calories consumed and calories expended over time. A sustained surplus supports weight gain, a deficit supports weight loss, and approximate equality supports weight maintenance, though body composition changes depend on more than calories alone.

A state in which a person consistently eats fewer calories than they expend, forcing the body to draw on stored energy. It is the fundamental requirement for weight loss, though the size and duration of the deficit affect muscle retention and adherence.

A drop in energy expenditure and metabolic rate that occurs during prolonged calorie restriction, caused partly by reduced body mass and hormonal signaling. It can slow weight loss and help explain plateaus, and it is often partly reversible with refeeds or maintenance periods.

A period of several weeks in which body weight stops changing despite continued effort. Common causes include unmeasured calorie creep, reduced non-exercise activity, water retention, adaptive thermogenesis, and changes in body composition that hide fat loss.

The calories burned through spontaneous daily movement such as walking, fidgeting, standing, and chores, excluding formal exercise. NEAT varies widely between people and often falls during dieting, which can quietly reduce total daily energy expenditure.

A macronutrient made of amino acids that supports muscle repair, immune function, and enzyme production. It supplies four calories per gram and is the most satiating macronutrient, making adequate intake important during weight loss and resistance training.

The nine amino acids the body cannot make in sufficient amounts and must obtain from food: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Their presence in a meal determines how well protein supports muscle protein synthesis.

A protein source that provides all nine essential amino acids in adequate amounts, such as meat, fish, eggs, dairy, soy, and quinoa. Plant foods that are incomplete on their own can be combined across a day to supply the full amino acid profile.

A branched-chain amino acid that acts as a key trigger for muscle protein synthesis. Leucine-rich foods such as dairy, eggs, meat, and soy are often emphasized around training and in protein distribution across meals.

The cellular process of building new muscle proteins in response to amino acid availability and mechanical stress from resistance training. It is elevated for hours after a protein-containing meal and is opposed by muscle protein breakdown.

A macronutrient that supplies four calories per gram and is the body's preferred quick energy source, stored as glycogen in muscle and liver. It also supports brain function and high-intensity exercise performance.

The storage form of carbohydrate in the liver and skeletal muscle. Muscle glycogen fuels intense exercise, while liver glycogen helps maintain blood glucose between meals and during fasting or sleep.

A ranking of how quickly a carbohydrate-containing food raises blood glucose compared with a reference food. It is influenced by fiber, processing, ripeness, and food combinations, and is most useful when applied to real mixed meals rather than in isolation.

A measure that combines a food's glycemic index with the amount of carbohydrate it actually contains in a serving. It gives a more practical picture of blood glucose impact than glycemic index alone, especially for foods eaten in small or large portions.

Indigestible carbohydrate found in plant foods that supports digestive health, satiety, and blood glucose control. Soluble fiber can help lower cholesterol and slow glucose absorption, while insoluble fiber adds bulk and supports regularity.

A macronutrient supplying nine calories per gram that supports hormone production, cell membranes, and absorption of fat-soluble vitamins. Dietary fats include saturated, monounsaturated, and polyunsaturated types, with essential fatty acids required from food.

Fats the body cannot synthesize and must obtain from diet, namely linoleic acid (omega-6) and alpha-linolenic acid (omega-3). They support cell membranes, inflammation regulation, and cardiovascular health, and are found in nuts, seeds, and oily fish.

Vitamins A, D, E, and K, which require dietary fat for absorption and are stored in body tissues. Because they are stored, excessive intake from supplements can reach toxic levels, unlike most water-soluble vitamins.

The B-complex vitamins and vitamin C, which dissolve in water, are generally not stored in large amounts, and are excreted in urine. They must be consumed regularly, and cooking methods that leach or destroy them can reduce intake.

A vitamin or mineral required in small amounts for normal physiological function, such as iron, calcium, vitamin D, and B12. Deficiencies can impair energy, immunity, and bone health, and some populations are at higher risk than others.

A family of nutrient intake reference values, including Recommended Dietary Allowance and Adequate Intake, used to plan and assess diets. Coaches use DRIs as benchmarks while recognizing that individual needs vary with age, sex, activity, and health status.

The feeling of fullness and reduced hunger that follows eating, influenced by food volume, fiber, protein, fat, and eating rate. Higher-satiety foods and meals can make a calorie deficit easier to sustain.

A goal written to be specific, measurable, achievable, relevant, and time-bound. In nutrition coaching it turns vague intentions like eating better into concrete actions such as adding a vegetable to lunch five days a week.

A concrete, written set of steps a client will take to move toward a goal, including what, when, and how often. Effective plans are small enough to be realistic and specific enough that the client knows exactly what success looks like.

The practice of tracking behaviors such as food intake, activity, sleep, or hunger, often through logs or apps. It raises awareness, provides data for coaching conversations, and is consistently linked to better adherence and outcomes.

A record of what, when, and how much a client eats, sometimes including hunger, mood, and context. It supports assessment and self-monitoring, but accuracy depends on honest recording and can be affected by underreporting.

A dietary assessment method in which a client describes everything eaten in the previous day. It is quick and low burden but captures only one day, so it may miss usual patterns and is often repeated or paired with other methods.

A structured questionnaire completed at the start of coaching that gathers health history, medications, allergies, lifestyle, goals, and prior experiences. It helps identify red flags, tailor recommendations, and decide when referral to a clinician is appropriate.

The legal and professional boundaries of what a nutrition coach may do, which typically excludes diagnosing disease, prescribing diets for medical conditions, or recommending supplement doses. Coaches must refer clients to qualified clinicians when needs exceed those boundaries.

A sign or symptom in a client's history that suggests a medical or psychological issue requiring referral, such as unexplained weight loss, chest pain, disordered eating, or pregnancy complications. Recognizing red flags protects both client safety and the coach's legal standing.

A client-centered conversation style that uses open questions, reflective listening, and affirmations to strengthen a person's own reasons for change. It reduces resistance and supports autonomy rather than telling clients what to do.

A model describing readiness to change in stages: precontemplation, contemplation, preparation, action, maintenance, and sometimes termination or relapse. Matching coaching strategies to a client's stage helps avoid pushing action plans on someone not yet ready.

A person's belief in their ability to carry out a specific behavior successfully. It grows through mastery experiences, modeling, encouragement, and reduced stress, and is a strong predictor of whether a client persists with a nutrition plan.

A return to a previous behavior pattern after a period of change, common in habit formation and often triggered by stress, environment, or overconfidence. Framing relapse as a learning event rather than failure helps clients resume progress faster.

A communication skill in which the coach focuses fully on the client, reflects back what was heard, and asks clarifying questions. It builds trust, uncovers barriers, and helps clients feel understood enough to explore difficult topics.

A question that invites explanation rather than a yes or no answer, such as asking what a typical weekday lunch looks like. It gathers richer assessment information and encourages clients to think through their own solutions.