1.8 Outline what physical activity level (PAL) is

This guide will help you answer 1.8 Outline what physical activity level (PAL) is.

Physical Activity Level, shortened to PAL, is a key concept in nutrition and health. It describes the amount of activity a person does in a typical day. PAL helps us work out how much energy a person uses. This energy use is sometimes called ‘energy expenditure.’

Knowing about PAL matters because it links physical activity to energy requirements. What you eat should match what you use, or you risk gaining or losing weight. PAL is not just for athletes or active workers. Everyone has a PAL—even if they lead a very quiet life.

Let’s look closely at how PAL is measured, what the different levels mean, and why this matters to health and wellbeing.

What is PAL?

PAL describes your average daily physical activity through a number. It is a ratio, showing how active you are compared to resting. This number is used by nutritionists to estimate a person’s total energy needs. It helps work out how many calories are required each day.

The basic formula for PAL is:

PAL = Total Energy Expenditure (TEE) / Basal Metabolic Rate (BMR)

Basal Metabolic Rate, or BMR, is the energy your body uses at rest. It keeps your body functioning—like keeping your heart beating, lungs working, and body temperature steady.

Total Energy Expenditure, or TEE, is your BMR plus any extra energy used for activity throughout the day, including walking, working, cleaning, sports, and all forms of movement.

PAL is, simply put, an average number showing how active someone is.

How is PAL Used in Nutrition and Health?

Dieticians and health professionals use PAL to find out how many calories a person needs. Calorie needs differ from person to person based on how active they are. Sedentary people use less energy than active ones.

Someone’s PAL guides eating plans. This avoids overfeeding or underfeeding. For example, a person with a higher PAL might need to eat more to stay healthy. The opposite is true for someone with a lower PAL.

Matching energy intake to expenditure lowers the risk of obesity or malnutrition. Knowing PAL is key for planning proper meals, supporting weight control, and setting up healthy habits for life.

Basal Metabolic Rate (BMR)

To understand PAL, start with BMR. BMR is how much energy your body needs just to survive if you were resting all day. This includes:

• Breathing
• Heartbeat
• Digestion
• Keeping organs working

BMR is measured in kilocalories (kcal) per day. Factors that affect BMR include:

• Age
• Gender
• Body size
• Muscularity
• Genetics

Most people’s BMR is between 60-75% of their total energy used daily. The rest comes from daily movement, which increases TEE.

Levels of Physical Activity

PAL values divide daily life into three main categories. Each category represents a particular lifestyle:

1. Sedentary or Inactive Lifestyle:

• PAL Value: About 1.2–1.3
• Little to no exercise
• Office jobs or sitting most of the day
• Minimal movement

2. Moderately Active Lifestyle:

• PAL Value: About 1.4–1.6
• Daily walking or standing
• Jobs needing some movement (e.g., teaching, retail)
• Regular but not heavy exercise

3. Vigorously Active Lifestyle:

• PAL Value: About 1.7–2.5
• Active jobs (e.g., construction, farming, delivery)
• Regular intense exercise or sports
• High energy output

Not everyone fits neatly into these categories. Individual PAL values can be calculated for a more accurate picture.

How to Work Out Your PAL

PAL is worked out by dividing TEE by BMR.

Here is a simple example:

• If your BMR is 1500 kcal per day
• Your TEE (total energy use—including movement) is 2250 kcal per day

PAL = 2250 / 1500 = 1.5

This person is moderately active.

Many online calculators can help estimate PAL. Health professionals use more precise tools, like physical activity questionnaires, activity trackers (wearable devices), or detailed diaries.

Factors That Affect PAL

PAL is affected by many daily habits. Key factors include:

• Work: Office, manual labour, shift patterns
• Transport: Walking, cycling, driving
• Recreation: Sports, gym sessions, hobbies
• Household chores: Cooking, cleaning, gardening
• Age: Children and teenagers often have higher PALs
• Health: Injury or illness may lower PAL

Different cultures and climates can also influence activity patterns. For instance, people in colder climates might be less active in winter.

Why is PAL Important?

PAL offers many benefits in health and nutrition planning.

Prevents Overeating or Undereating

• Correctly matching energy intake to expenditure prevents weight gain or weight loss. For people wanting to maintain weight, this balance matters.

Helps Design Personalised Diet Plans

• Knowing someone’s PAL helps create unique and suitable meal plans, avoiding one-size-fits-all advice.

Supports Health Goals

• Proper activity helps control blood sugar, cholesterol, and blood pressure. It reduces risks of long-term diseases, such as heart disease and type 2 diabetes.

Guides Public Health Recommendations

• Bodies such as Public Health England use PAL to set general food and activity guidelines for the population.

Measuring Energy Expenditure

Energy expenditure can be measured in different ways. Methods range from scientific lab equipment to simple self-reporting.

• Indirect Calorimetry: This is equipment that measures oxygen use and carbon dioxide production. It’s very accurate but costly and limited to lab settings.
• Doubly Labelled Water method: A very precise test for research. Participants drink water with special markers, and scientists measure how fast these markers leave the body. This method is rarely used outside studies.
• Activity Trackers: Wearable devices, like fitness watches or pedometers, estimate energy use based on steps and heart rate.
• Activity Diaries: People record what they do every hour. Results rely on honesty and attention to detail.

For day-to-day life, most people use a combination of simple tools and professional advice to estimate PAL.

Negative Effects of a Low PAL

Low PAL, or inactivity, has harmful effects on the body and mind. Not being active enough has links to:

• Increased weight and obesity
• Type 2 diabetes
• Heart disease
• Poor mental health, such as depression and anxiety
• Weaker bones and muscles
• Loss of fitness and strength
• Poor blood circulation

Long periods of sitting or very low movement make it hard to manage energy balance. Physical activity breaks up the day and supports wellbeing.

The Benefits of a Higher PAL

A higher PAL means more movement during the day. This may help:

• Maintain a healthy balance between energy in and energy out
• Lose weight or prevent weight gain, if needed
• Lower cholesterol and blood pressure
• Control blood sugar
• Support bone strength
• Improve mood and reduce anxiety

A higher PAL usually means a person is meeting physical activity guidelines, like 150 minutes of moderate-intensity activity each week for adults.

PAL in Special Groups

Some people have special energy needs because of their PAL:

• Children and Teenagers: Often more active. Need higher energy intake, especially during growth spurts.
• Pregnant Women: Often need extra energy. PAL may change due to tiredness or other symptoms.
• Older Adults: May have a lower PAL due to slow walking or limited movement. Need careful balance to avoid losing muscle.
• Disabled or Injured People: Movement may be limited. Specialist advice is needed to calculate PAL and plan safe activity.

Adjusting Diet Based on PAL

When planning a diet, consider both BMR and PAL. This makes sure a person eats enough to meet their needs, but not more than what is used.

Steps for adjusting a diet:

1. Measure or estimate BMR.
2. Work out typical PAL based on daily movement.
3. Multiply BMR by PAL to get calorie needs.
4. Adjust calorie intake if weight goals exist.
5. Make meal plans that match both energy and nutrient needs.

This method helps personalise support and keeps people on track for their goals.

Common Misunderstandings About PAL

Many people overestimate how active they are. They might think housework or a short walk each day means they have a high PAL. In reality, vigorous activity or movement throughout most of the day is needed for a high PAL score.

It’s important to be honest when looking at your own activity level. Food choices should match movement. Regular checks or updates help make sure you stay on track.

Limitations of PAL

While PAL is a useful guide, it has limits. It is based on averages, and lifestyle can change from day to day. PAL does not show what types of activities are done—so it cannot say if movement counts as strength, flexibility, or cardio fitness.

PAL also does not easily reflect differences in metabolism between individuals, such as between men and women, or changes caused by illness or medication.

Supporting People to Improve Their PAL

Encouraging more movement can raise a person’s PAL. Useful steps include:

• Standing up regularly during the day
• Walking or cycling to work
• Taking the stairs instead of lifts
• Scheduling exercise sessions
• Joining dance, sport, or walking groups

Small changes add up over time. Support from friends or family helps. Celebrate progress to build good habits.

Regular Review of PAL

Life events, illness, injuries, and changing jobs can alter PAL. Regular reviews mean energy intake can be adjusted if needed.

Health workers may ask people to keep an activity diary for a few days. New technology, like smart watches and phone step counters, can help with monitoring movement and estimating PAL. Data can be reviewed for trends over weeks or months.

Using PAL with Other Health Information

When making a nutrition or health plan, consider more than just PAL:

• Height and weight
• Muscle and fat mass
• Medical history
• Current activity levels
• Personal goals

PAL provides a starting point, but getting a full picture allows for more sensible decisions about food and exercise.

Final Thoughts

Physical Activity Level, or PAL, is a practical way to measure how much physical movement a person does each day. It is used by health professionals to work out how many calories a person needs, based on both rest and activity. PAL helps to balance food intake and energy output, keeping weight steady and supporting good health.

Understanding your own PAL can support better food choices and inspire more movement in daily life. People sometimes overestimate their activity, so self-reflection and regular check-ins are helpful.

Inactivity puts the body at risk of illness, low mood, and lost fitness. Increased movement, supported by simple changes and encouragement, brings lasting benefits. PAL is only part of someone’s full health story, but used with other details, it builds a strong foundation for lasting wellbeing.

Being aware of your own PAL, making adjustments when situations change, and seeking support when needed are all positive steps. Over time, these habits help maintain a healthy balance, support energy, and improve your overall quality of life.