NASM-WLS key terms

The relationship between calories consumed from food and beverages and calories expended through resting metabolism, digestion, and physical activity. A sustained deficit drives weight loss; a surplus drives weight gain.

Consuming fewer calories than the body expends over a given period. It is the fundamental requirement for weight loss, though the size, rate, and sustainability of the deficit affect body composition and adherence.

The sum of all calories burned in a day, comprising resting metabolic rate, thermic effect of food, exercise activity thermogenesis, and non-exercise activity thermogenesis. It sets the reference point for designing a deficit.

The calories required to maintain basic physiological functions at rest, typically the largest component of daily energy expenditure. It declines with loss of fat-free mass and during prolonged energy restriction.

The energy cost of digesting, absorbing, and metabolizing nutrients, roughly 10 percent of intake on average. Protein has the highest TEF, which modestly favors higher-protein diets during weight loss.

Energy expended through spontaneous daily movement such as fidgeting, standing, walking, and routine tasks. It varies widely between individuals and often falls during dieting, slowing weight loss.

The physiological slowing of energy expenditure that accompanies weight loss, driven by reduced body mass, lower thermic effect of food, and declines in NEAT. It can shrink the expected deficit and stall progress.

A drop in energy expenditure beyond what is predicted from lost body mass alone, reflecting hormonal and sympathetic nervous system changes during caloric restriction. It contributes to weight regain after dieting.

All body tissue other than fat, including muscle, bone, organs, and water. FFM is the primary driver of resting metabolic rate, so preserving it during weight loss helps protect daily energy expenditure.

The relative proportions of fat mass and fat-free mass in the body. Weight loss quality is judged by changes in these proportions, not by scale weight alone.

A screening ratio of weight in kilograms to height in meters squared, used to classify underweight, normal, overweight, and obesity. It does not distinguish fat from muscle or indicate fat distribution.

A tape measurement around the abdomen used to estimate visceral fat and cardiometabolic risk. Elevated values flag risk even when BMI falls in the normal range.

Adipose tissue stored around internal organs in the abdominal cavity. It is metabolically active and strongly linked to insulin resistance, inflammation, and cardiovascular disease.

Adipose tissue stored directly beneath the skin, most visibly on the hips, thighs, and abdomen. It is less strongly associated with metabolic disease than visceral fat but still contributes to energy storage.

A chronic, multifactorial condition of excess adiposity that impairs health, commonly classified by BMI of 30 or higher. Its causes span genetics, environment, behavior, hormones, and medications.

The combined likelihood of developing cardiovascular disease and metabolic disorders such as type 2 diabetes, hypertension, and dyslipidemia. Excess visceral fat and inactivity raise this risk.

A condition in which muscle, fat, and liver cells respond poorly to insulin, prompting higher insulin output to control blood glucose. It is common with excess adiposity and improves with weight loss and activity.

The grams of protein consumed daily, especially important during caloric restriction. Adequate protein supports satiety, preserves fat-free mass, and raises the thermic effect of food.

The goal of retaining muscle and other fat-free tissue while losing fat. It is supported by adequate protein, resistance training, and a moderate rather than aggressive caloric deficit.

Exercise that loads muscles against external resistance to build or maintain strength and size. During weight loss it signals the body to retain muscle, protecting metabolic rate and function.

The speed at which body weight decreases, often expressed as pounds or kilograms per week. Moderate rates better preserve lean mass and are easier to sustain than rapid loss.

A period in which scale weight stops changing despite continued effort. It can reflect metabolic adaptation, reduced adherence, water shifts, or a deficit that no longer exists.

The feeling of fullness and suppression of hunger after eating. Protein, fiber, volume, and slower eating all increase satiety and can improve adherence to a caloric deficit.

Indigestible plant carbohydrates that add bulk, slow digestion, and promote fullness. Higher fiber intake is associated with better weight management and metabolic health.

The calories per unit weight of a food. Low energy density foods, such as vegetables and lean proteins, let clients eat larger portions for fewer calories, supporting satiety and adherence.

Systematically tracking behaviors such as food intake, activity, and body weight. It is one of the strongest predictors of weight-loss success because it builds awareness and accountability.

The degree to which a client consistently follows a plan over time. Long-term adherence, more than the theoretical superiority of any diet, determines weight-loss outcomes.

The process of adopting and sustaining health behaviors through strategies such as goal setting, self-monitoring, stimulus control, and problem solving. It is central to coaching for weight loss.

A client-centered counseling style that uses open questions, reflective listening, and affirmation to strengthen a person's own reasons for change. It reduces resistance and supports autonomy.

A person's belief in their ability to perform a specific behavior or overcome obstacles. Higher self-efficacy predicts better adherence and persistence during weight-loss efforts.

Objectives framed as specific, measurable, achievable, relevant, and time-bound. This structure turns vague intentions into concrete actions clients can track and adjust.

Negative stereotyping and discrimination directed at people because of their body weight. Internalized stigma can harm mental health and reduce engagement in health-promoting behavior.

Sustaining a reduced body weight after intentional loss. It requires continued self-monitoring, physical activity, and skills to manage hunger and environmental triggers long term.

The return of lost body weight after a diet ends, common due to metabolic adaptation, reduced adherence, and environmental pressures. It is a normal physiological response, not a personal failure.

The set of dietary and behavioral strategies used to control appetite during a caloric deficit, such as higher protein and fiber, adequate sleep, hydration, and planned meals.

The duration and restfulness of nightly sleep. Poor sleep disrupts appetite hormones, raises hunger, reduces training quality, and is associated with weight gain and poorer dietary choices.

The regulation of blood glucose within a healthy range. Weight loss, physical activity, fiber, and balanced meals can improve glycemic control in people with insulin resistance or type 2 diabetes.

Public health recommendations for weekly aerobic and muscle-strengthening activity. Meeting them supports energy expenditure, cardiovascular health, and weight maintenance during and after loss.