Foundational Concepts

As a personal trainer, clients will seek your guidance on nutrition for health, performance, and body composition. This topic will provide an overview of what nutrition is and why it's important for trainers to understand, look energy in and energy out (a fundamental concept of nutrition), and the Ministry of Health guidelines for healthy eating.

But before we get into the science of nutrition, let's take a moment to think about food and eating holistically.

Nutrition is about what makes up the food we eat, how this affects the body, and how we can use nutrition practices to improve health outcomes and reduce the risk of disease. Sports nutrition applies nutrition principles to optimise sporting performance, weight management, and overall health in athletic populations.

Nutrition plays a crucial role in our overall health and wellbeing. Essential nutrients support optimal physiological processes such as muscle contractions, digestion, eyesight, and cellular signalling. Without adequate nutrition, the body is at risk of disease and decreased overall functioning.

Why do personal trainers look at nutrition?

We look at nutrition to support our clients with:

• Health
• Performance
• Body composition

Some groups may fall under more than one category. Think back to what you know about non-communicable diseases. Diet is a major cause of health loss in New Zealand and a key contributor to cardiovascular disease. Cardiovascular disease accounts for 1 in 3 deaths in New Zealand and is the leading cause of death in women globally (Heart Foundation, 2021).

It is important to remember the significance of adequate food consumption and discuss this information with your client when working with them to achieve their health and fitness goals. Good nutrition assists in leading a healthy lifestyle. When good nutrition and physical activity are combined, it can help to reach and maintain a healthy weight, reduce the risk of chronic diseases, and promote overall health and wellness.

Body composition and health

Body composition is directly related to nutrition and can result in various health conditions linked to being overweight or underweight.

Health conditions associated with excess weight:

• Type 2 diabetes
• Cardiovascular disease
• Hypertension
• Metabolic syndrome
• Some cancers
• Musculoskeletal conditions
• Respiratory conditions
• Sleep apnoea
• Gall bladder disease
• Hernia
• Reproductive disorders
• Urinary incontinence
• Fatty liver disease
• Depression and other mental health conditions

Many obesity-related health conditions are preventable and reversible through healthy eating, an active lifestyle, and weight loss.

Health conditions associated with being underweight:

• Body dysmorphic disorder
• Anorexia nervosa
• Binge eating
• Osteoporosis
• Decreased muscle strength
• Hypothermia
• Malnutrition and vitamin deficiencies
• Anemia
• Reproductive disorders
• Decreased immune function
• Developmental/growth delays (in children)
• Depression and other mental health conditions

Fitness professionals are not expected to be experts in these health conditions. However, you may become familiar with some of the common symptoms through your studies and work and therefore may be able to recognise when a client should be referred to a suitable medical or allied health professional.

Alternatively, you may work with clients already diagnosed with one or more of these conditions. In this case, the client will likely have a medical or allied health professional already. You may be able to work alongside these professionals to help develop the fitness component of the client's wellness plan.

So, now that we know why it is important to understand nutrition, what do we need to know?

To understand nutrition guidelines and principles, it is first important to understand the relationship food has with energy - the concept of energy in and energy out.

The human body gains energy through food consumption. This source of energy is known as a calorie. Food calories are absorbed into the body when consumed, creating energy for the body to perform. This is known as energy in.

The body uses the stored energy from the calories eaten for daily requirements such as physical activity and exercise. This is known as energy out.

Energy balance

If someone exhibited more ‘in’ than ‘out’ over time, this would result in weight gain. On the other hand, if someone exhibited more ‘out’ than ‘in’, over time it would contribute to weight loss. However, an active individual with more 'out' than 'in' would experience fatigue during physical activity as their body does not have enough energy to sustain maximum performance. This is why it is essential to monitor and balance your energy intake and energy output.

We can balance energy by manipulating:

• the amount and type of food consumed.
• the time and frequency of consumption.
• energy expenditure (exercise).

Many clients' goals involve energy balance because it is the underlying principle behind weight loss and gain.

Energy in	Energy out
Food Beverages	BMR (basal metabolic rate) TEF (thermic effect of food) Exercise or EAT (exercise activity thermogenesis) NEAT (non-exercise activity thermogenesis)

For general population clients, results are achieved with consistency over time. The tools you learnt for behaviour modification are just as relevant when approaching nutrition as they are to physical activity. Implement small changes for long periods of time to see consistent results.

Big changes for short periods of time results in 'yo-yo dieting'. Yo-yo dieting is a very common situation in which people struggle to maintain their target weight. This is also known as “weight cycling,” which means gaining weight unintentionally and dieting in response, then regaining that weight once again.

The calorie: The measure of energy in food

A calorie is a measurement of energy (or joules/kJ). There are 4.2kJ in 1 calorie (kcal). Kilocalories are often called ‘calories’. For example, someone may say ‘this food is 100 calories’ but the technically accurate statement would be ‘this food is 100 kilocalories’.

Calories power cellular processes and are stored for future energy use (1kg of fat is approximately 9,000 cal). Many clients may have questions about calorie intake or "how to burn off calories". But energy balance and calories are quite a nuanced topic. Watch the video and answer the questions that follow.

After you have watched the video, answer the questions to check your understanding.

It's important to remember that the energy on food labels is not necessarily what your body can use, and may differ from person to person. For example, some foods with high amounts of fibre may not give you all the energy the label claims to, because we cannot digest it all.

It can be difficult to calculate calorie (energy) intake and requirements because there are a lot of factors that come into play, such as age, activity level, enzyme level, gut bacteria, intestine length, and sex.

So how much energy is required? We need to determine the quantity of energy (calories) required for balance. We can estimate this using many different calculations. In this course we will cover the calculations below as well as using a macronutrient calculation in future sections.

*IMPORTANT NOTE Please note that the macronutrient calculations is what you will use for assessments.*

Let us first look at the following:

• Basal metabolic rate
• Total daily energy expenditure

“Adhere to professional, safe practice. Simply increased calorie expenditure will yield great results to begin with. Advise against fad or yo-yo dieting, which is a similar approach to an exercise 'quick fix'.”

Now you have learnt some fundamental information regarding energy/calorie calculations that you can use on yourself and with your clients in industry. As mentioned earlier, there are many approaches to calculating your own or your client's energy requirements. In this course, we focus on calculating the calories required from each macronutrient and adding them together to find total calorie requirements depending on weight and activity levels. You will learn about macronutrients and how to calculate requirements in following topics. Keep this in mind when preparing for your assessments.

Basal metabolic rate (BMR)

BMR is an estimate of the calories expended if you were to do nothing but rest for 24 hours. It represents the minimum amount of energy needed to keep the body functioning, e.g., breathing, heart beating, nutrient processing, and cell production. In other words, the amount of energy your body needs to maintain homeostasis. It is roughly 70% of total daily energy expenditure.

BMR takes into consideration height, weight (BMI), age, and sex.

Women:

• BMR = 655 + (9.6 × weight in kg) + (1.8 × height in cm) – (4.7 × age in years)

Men:

• BMR = 66 + (13.7 × weight in kg) + (5 × height in cm) – (6.8 × age in years)

Try it out

Let's work through an example together, and then try it yourself.

You have a client who is a woman, weighs 79kg, is 168cm, and aged 34. We can plug this data into the formula to calculate BMR. Remember BEDMAS and calculate the values inside the brackets first.

• BMR = 655 + (9.6 x 79) + (1.8 x 168) - (4.7 x 34)
• BMR = 655 + 758.4 + 302.4 - 159.8
• BMR = 1556

Now it's your turn.

There are many apps and websites that offer BMR calculations which can be handy for quickly calculating BMR on the job. But you should get comfortable using the formula to calculate BMR first, so you can validate any apps or website calculators.

Total daily energy expenditure (TDEE)

TDEE is essentially a multiple of your BMR. It uses the Harris-Benedict Equation to apply an activity factor to the BMR to determine total daily energy expenditure in calories. TDEE is the sum of BMR, NEAT, EAT, and TEF.

Activity	TDEE (calories)
Sedentary (little or no exercise)	BMR x 1.2
Lightly active (light exercise/sports 1-3 days a week)	BMR x 1.375
Moderately active (moderate exercise/sports 3-5 days a week)	BMR x 1.55
Very active (hard exercise/sports 6-7 days a week)	BMR x 1.725
Extra active (very hard exercise/sports and a physical job)	BMR x 1.9

Try it out

Use the BMR formula and the Harris-Benedict Equation to calculate the total calorie requirement for either yourself or a friend or family member.

How does your TDEE compare to standard recommendations of 2,000 a day for women and 2,500 a day for men?

Thermic effect of food (TEF)

The process of digestion requires energy. Protein takes up to 5 x more energy to digest than fats and carbohydrates. TEF is roughly 10% of TDEE.

• TEF = TDEE x 0.1

EAT and NEAT

EAT is exercise activity thermogenesis and NEAT is non-exercise activity thermogenesis. NEAT is the calories used through movement outside of planned exercise. E.g., walking to the bathroom to shower, running to catch a bus, and even shifting around in your seat. It accounts for approximately 15% of TDEE. EAT is the calories from any planned exercise. It accounts for approximately 5% of TDEE.

• NEAT = TDEE x 0.15
• EAT = TDEE x 0.05

Energy balance

Once you have calculated a client's required daily calories, you can use this information to support their weight goals.

• Consume daily required calories to maintain weight.
• Consume more than the daily required calories to gain weight.
• Consume less than the daily required calories to lose weight.

Adhere to professional, safe practice. Simply increased calorie expenditure will yield great results to begin with. Advise against fad or yo-yo dieting, which is a similar approach to an exercise 'quick fix'.