Lesson video

Hello there and welcome to this lesson called "A Balanced Diet for Health and Performance" from the Health and Well-being Diet and Nutrition Unit.

My name's Mr. Broome.

We've got a packed lesson here full of loads of useful information on nutrition and the nutrients that your body needs to be able to perform your physical activities and sports.

Let's get straight into it.

Okay, so by the end of today's lesson, you should be able to explain the role of various macro and micronutrients in the balanced diet and their impact on physical performance and health and optimum weight, all sorts to fit in today's lesson.

Let's have a look at our keywords of four of them.

Macronutrients and micronutrient, optimum weight and hydration.

Again, pause here if you want to have a closer look at those.

As I've said, a very busy lesson.

Four parts to this lesson.

First of all, we're describing the role of macronutrients.

Okay, so have a quick look at this label, maybe pause the video if you want to have a closer look.

Aisha's asking, "Do you know what the three missing words are?" Well, they are the names of the three macronutrients.

They are carbohydrates, protein, and fat.

I wonder if you've got those.

Well done if you did.

So very quick check for your understanding, which of these are the names of the three macronutrients? Is it A, fat, vitamins, protein? B, fibre, carbohydrates, protein? C, fat, minerals, protein? Or D, carbohydrates, protein, and fat? Which ones do you think? Well done if you said D, carbohydrates, protein, and fat.

Moving on, so let's have a look at some of these in closer detail.

Carbohydrates, we'll focus on that first, are the body's main source of energy.

And around 50% of our calories should come from carbohydrate sources.

In physical activity, we'll use carbohydrates for energy for both aerobic and anaerobic activities.

And they come in two forms, complex and simple.

Good sources of complex carbohydrates are things like pasta, potatoes, bread, and rice.

Now complex carbohydrates are stored in the muscles as glycogen and can provide energy over a long period of time.

So that's the way the muscles will go to the glycogen stores and use them for energy.

But simple carbohydrates on the other hand are instant energy because they are sugars which are quickly digested and absorbed.

Some sources of simple carbohydrates are natural while others are processed.

Let's have a look at some examples.

Fruit and honey are natural sources of simple carbohydrates and chocolate and refined sugar are processed examples of simple sugars.

Now fat is also a source of energy.

The body uses fat for energy during low intensity, long duration activities, particularly after carbohydrate stores have been depleted or used up because remember, carbohydrate stores are the preferred type of energy for the body.

And sources of unsaturated fat, which are healthy can come from things like olive oil and avocados and fish.

And sources of saturated fat, which are unhealthy types of fat can be from butter and snack foods.

Jacob says, "Shouldn't we avoid eating fat?" That's a common idea, isn't it? That we shouldn't ever eat fat.

Some people believe that.

Actually, no.

Fat gets a bad reputation, but it plays a really important role as part of a healthy balanced diet.

And actually around 30% of our daily calories should be from fat sources.

And fat rich foods are calorie dense due to each gramme of fat containing more than double the calories of a gramme protein or carbohydrate.

So therefore you should try and avoid eating too many fatty foods because quite quickly you'll have eaten a lot of calories, so they should be eating a moderation to avoid that calorie surplus.

Let's have a look there.

This diagram demonstrates just how nine calories in one gramme of fat compared to four in a gramme of protein or carbohydrate.

True or false? Fat-free diet would be ideal for everyone.

What do you think? That is false and why is that? Well, fats are an important source of energy.

Fat free is not a good idea because we need fats as an energy source and they play other roles, importantly in keeping the body healthy.

Fat should be included in a balanced diet and should provide around 30% of our daily calories.

And what about the third and final one? It was protein, wasn't it? 'Cause a protein should make up around 20% of our calorie intake and it plays a small role in providing us with energy, but that job really is carbohydrates followed by fats.

Protein instead has a main role and that is in growth and repair of muscle tissue, meaning it plays a really vital role in recovery from exercise.

Good sources of protein include meat, fish, nuts, and eggs.

Now here we have a pie chart showing us the approximate balance of macronutrients in your daily diet, and you can see that half of our calories ideally would come from carbohydrates.

Here's your practise task for this section.

Alex regularly goes circuit training, which includes lifting weights and lots of aerobic exercise.

He makes himself a tuna salad consisting of tuna steak, lettuce, and tomatoes.

Two parts to this then.

Number one, how well does this meal seem to meet the recommended balance of macronutrients? Write a sentence for each macronutrient.

And number two, what is the overall effectiveness of this meal For Alex? Write a brief review.

Pause the video here and complete those two parts of the task and rejoin me for some answers.

Okay, so things you might have said.

So carbohydrates that isn't really a good source of carbohydrates in that meal, which should provide 50% of your daily calories.

Protein, yes, the tuna steak is a really good source of protein, seems to be plenty of protein there.

And fats while tuna actually again is a good source of healthy unsaturated fats.

So he's ticked two of the boxes there, hasn't he? What might you have suggested? Well, this meal does provide Alex with some good source of protein and healthy fats and he's going to need protein to recover from his training for growth and repair and also some fats for energy.

However, there is a lack of carbohydrates and if he's working hard, he's gonna need carbohydrates for plenty of energy to complete his circuit training.

So you might benefit Alex by adding a portion of complex carbohydrates, something like rice or pasta.

Well done if your answer is similar to mine.

That brings us to the second part of the lesson and that's to describe the role of micronutrients and fibre.

Let's have a look.

So micronutrients are important components of a healthy diet, but Sophia asks, "Why do you think they might be called micronutrients?" And we had macro earlier.

Well, the reason is micro means small.

They're called micronutrients because they are only required in small amounts when compared to those macronutrients.

Now micronutrients can be split into two types, vitamins and minerals.

And vitamins in particular, we're gonna look at first.

Vitamins play essential roles in helping your body to grow and function properly.

Each vitamin is found in different foods, highlighting the need to eat a colourful and varied diet.

There's lots of vitamins.

You can have a look here.

They're generally named.

well, they are all named after letters.

We have vitamin A, B, C, D, and E, and they each have their own role, which you can have a look at there.

Ensuring you get all the vitamins in your diet will help you to.

Is it A, maintain your immune system? B, ensure you never get tired? C, guarantee you don't gain weight? Or D, support your vision? What do you think? Well, there were two correct answers there.

A, it will help maintain your immune system.

And D, support your vision.

Okay, well done if you recognise A and D.

And let's go to the other micronutrient, which is minerals.

What do we know about minerals? Well, minerals are essential for maintaining a healthy body as well.

Two of the most essential minerals that you're going to need to know about are calcium and iron.

I wonder if you've come across those before.

Let's have a look.

So calcium or iron, which one do you think before I reveal? Yes, calcium.

It helps us to grow teeth and bones and to keep them strong and dense.

It's found in milk, cheese, broccoli, and cereals, amongst other things.

Iron on the other hand is needed to form haemoglobin, a word I'm sure you're familiar with.

Sam said, "What is the important job of haemoglobin?" It's sort of very important job actually.

What do you think? Well, haemoglobin is the part of a red blood cell which carries oxygen, hence the picture on the left.

And iron can be found in many foods such as meat, beans, and spinach.

Let's just check your understanding.

Is this true or false? Haemoglobin is important in performing well in sport and so sports people need to have iron in their diet.

What do you think? That's true, absolutely true.

Why? Well, haemoglobin is vital when it comes to performing in sports because working muscles need a constant supply of oxygen to produce energy.

Low ion levels in the diet will hinder the ability to transport oxygen where it is needed and performance will suffer as a result.

Well done if you said true.

How about fibre? Well, fibre is the final component needed in a balanced diet.

We've had carbohydrates, proteins, fats, minerals, vitamins, and now we have fibre finally.

Fibre is the part of your food that the body can't digest and it's found in foods like fruits, vegetables, and whole grains and it plays an important role in aiding the digestive system, keeping your bowel movements regular, and balancing blood sugar levels.

So all of these play a very important role, don't they? Here's a task for this section called describe the role of micronutrients and fibre and we have here on the left Alex and Alex is a triathlete.

I'd like you to give an example of how calcium, iron, and one of these other vitamins can help Alex's performance over the season.

Name the mineral and vitamin alongside the impact it will have on Alex's performance.

Pause the video here and answer those questions and rejoin me again in a second for some answers.

Okay, so what might you have said about Alex? Calcium, you may have chosen to talk about calcium, will help to keep Alex's bones dense and strong.

That means he's less likely to get injuries to his skeletal system such as stress fractures, which if he got those injuries would mean he has to miss competitions.

How about iron? Well, iron as we know is vital to Alex as an endurance athlete because it's used to form haemoglobin and that's gonna transport the oxygen he needs to compete and supply enough to perform well in training and competitions and avoid fatigue.

And triathlon is an event where it's very easy to become fatigued.

We also had vitamin, so what might you have said? Vitamin A, to help Alex's immune system to keep him healthy and free of illness, therefore able to train and compete.

Vitamin B, to help Alex produce energy which he needs to train and compete.

Vitamin C will help Alex's immune system to keep him healthy and free of illness, therefore able to train and compete.

Vitamin D will help keep Alex's muscles functioning so that he can perform at his best.

And vitamin E will help Alex's immune system to keep him healthy and free of illness, therefore able to train and compete.

So as you can see, lots of reasons why vitamins and minerals are really useful for helping somebody to continue to be able to train for their event and compete in their event and not have to miss time through illness or injury.

Vital we get the right amount of micronutrients into our diet.

Third part of the lesson is called explain sports specific diets and optimum weights.

Okay, so what is optimum weight? It means the weight somebody should be on average taking into account for factors and that is the sex of the person, the height of the person, the bone structure, and the muscle girth.

We're gonna learn a little bit more about those now.

"How do they each affect optimum weight?" Wonders Laura.

How do you think sex, height, bone structure, and muscle girth might impact what your optimum weight is? Let's find out, shall we? So sex, males are generally heavier due to having greater muscle mass.

You would generally expect a male to have a higher optimum weight.

Height, well, the taller you are, the greater your optimum weight.

Okay, that probably makes sense to you.

Okay, if you're a taller person, you would expect a taller person to be naturally heavier than a shorter person and that optimum weight would be heavier.

Bone structure, so if you have bigger and denser bones, it means you're higher optimum weight.

And muscle girth, so muscle thickness essentially will mean higher optimum weights for those people with big muscles.

Okay, so Lucas says, "What is the optimum weight for somebody who competes in a sport?" What do you think about that? Well, it's a slight trick question that there isn't one because different sports have different optimum weights.

Sometimes even different positions in the same sport have different optimum weights.

So perhaps in rugby there's an ideal weight for one of the positions which is different to the ideal weight for another position on the team.

Some examples.

Okay, so in sumo wrestling, the national sport of Japan, wrestlers' average weight is around 170 kilogrammes.

The average male professional footballer, however weighs around 77 kilogrammes and the average weight of a professional jockey is around 50 kilogrammes.

So we've got three different types of sports person there and you can see vastly different average weights.

Here's some more examples.

So here we have Keely Hodgkinson.

Now Keely's a middle distance runner and if you run middle or long distance, you're gonna benefit from having a lighter weight because it's more energy efficient.

You don't wanna have to try and move a heavy body around the track, it's going to take more energy to do so.

And so the optimum weight for somebody who runs a middle distance or a long distance is going to be quite light.

They don't want to be heavy.

On the other hand, somebody who's a power lifter, they're much heavier because they require a much, much greater muscle mass to move the heavy weights.

Essentially their competition is about who can lift the most weight and so the more muscle they have, the better.

And so clearly that muscle girth is going to be much bigger and therefore their optimum weight will be higher.

Now sports people can highlight some of the limitations with using body mass index, BMI as a measure of health and I'm sure you've come across BMI previously.

Here's a really good example.

We have Owen Farrell there on the left who's a rugby player.

He's 188 centimetres tall, and weighs 96 kilogrammes.

And those are the two measures you need to be able to work out someone's BMI.

His BMI therefore is 27.

2 and that tells us that he's overweight as you can see here on the BMI chart.

Now Alex says, "Why might this be an inaccurate description of Farrell's weight?" What do you think about that? Does he look like he's overweight to you? So rugby players, for example, Owen Farrell have a higher optimum weight because of the demands of the game such as tackling or barging past people, okay? They need to be big and strong.

So rugby players generally will have a greater muscle mass or muscle girth and have denser bones.

So BMI, using this weight measurement but not considering whether weight is due to having lots of muscle and dense bones or having a lot of fat.

And in the case of Owen Farrell and other rugby players, it will be because they have lots of muscle and probably very dense strong bones that their body is heavier.

But BMI doesn't recognise that and so athletes often find that their BMI might say that they're overweight or even obese when actually they're in really good shape.

Quick check for your understanding.

Which of these are most likely to have the optimum weight to be a professional jockey? A, B, or C? Well done if you said A.

Okay, why is that? Well, the lighter frame, there's not a huge amount of muscle there is there on person A.

A muscle girth is going to contribute to added weight.

And C has a heavier body than A, which isn't going to be ideal to be a professional jockey because you want to be as light as possible so the horse doesn't have to work so hard.

Okay, John's got a question for you, quite a long one, so follow along with me.

"If complex carbohydrates provide us with energy stored as glycogen in the body, in the muscles, which type of sports person would want to maximise how much they have stored?" So who would really want to focus on getting as much glycogen as possible stored in their muscles before they compete? What do you think? Well, well done if you were thinking of endurance athletes such as marathon runners.

They will maximise how much glycogen they have stored for an event using a method called carbohydrate loading.

Something we're gonna look at now.

So carbohydrate loading is when athletes will eat a lot more carbohydrate rich foods than usual, commonly pasta in the few days before the competition.

In fact, sometimes the event organisers for something like a marathon or a triathlon will even arrange a pasta party for competitors the night before a race to allow them to load up on carbohydrates.

Now in conjunction with this increase in carbohydrates, athletes will also taper their training at the same time.

That means they greatly reduce their training load.

Okay, so for that last six or seven days before the marathon, they won't train as hard as they have done in previous weeks.

They will reduce their training rate, their training load and they will increase their carbohydrate intake.

What's the result of that? Well, tapering training plus carbohydrate loading means the stores of glycogen in the muscles are maximised and that will hopefully lead to the athlete being able to perform for a long, long time before they get tired, maybe even complete the whole event before they get tired because they can rely on all that glycogen stored in their muscles.

Okay, so carbohydrate loading is a popular method with endurance athletes for a few reasons and it's mainly because their events are long in duration and refuelling is not always possible.

You might see cyclists and marathon runners eating some sort of gel to give them some instant fuel because it's a simple sugar, but it's not gonna satisfy all the energy needs they have during the race.

And so they need to make sure they've got as much energy stored away before they begin.

Now their events require a lot of energy to complete successfully, okay? Think about the energy it takes to complete a marathon or to complete a stage on tour cycling.

Now power athletes such as sprinters wouldn't benefit from carbohydrate loading.

Their diet will provide enough energy for their event without the need to load.

So people who are in shorter events like the sprints, maybe 10, maybe 20 seconds worth of action, they don't have to worry about stocking up on carbohydrates before they compete.

It's not something that they need to worry about.

However, what they might need to pay a lot of attention to is a different aspect of their diet.

This is because their training will involve a lot of strength training, heavy weight training, or doing plyometrics to achieve muscular hypertrophy.

Andeep says, "This type of training causes microtears in the muscles like tiny tears.

Which macronutrient is especially important because of this?" Thinking back to the start of the lesson.

Hopefully you said protein because protein is the vital macronutrient for repairing microtears and growing muscles.

Its main job is growth and repair.

So protein should be consumed as soon as possible after exercise for these power athletes, ideally within a golden window of one hour.

That's why protein shakes and protein bars have become really popular because they're very convenient and a way of getting protein into your body very, very quickly.

So timing protein intake in this way will maximise protein synthesis.

That means the muscles will recover as quickly as possible.

So get your protein in in the first hour after exercise.

So Lucas is here and he says, "Look, this chart here in the top left hand corner is the approximate balance of micronutrients for people in general." And we've seen this already, hopefully we're familiar with this already, "But who do you think these other diets might suit?" Let's have a look.

In the bottom left there, we have one with 30% protein and the bottom right there, we have one with 65% carbohydrates.

Who do you think they would suit? Pause if you want to have a little bit longer to think because I'm going to reveal the answers now.

So we are looking at power athletes there in the bottom left with more protein than the average person would need and endurance athletes there on the bottom right with more carbohydrates than a normal person would need.

And hopefully you can understand the reasons why, but just to be very brief on it, more protein because you want to have growth and repair from all that heavy weight training and endurance athletes, more carbohydrates because they want to fuel all those long distance endurance events and training sessions that they take part in.

Quick check for understanding.

Do these athletes need to focus more on carbohydrate loading or timing their protein intake? Let's have a look what athletes we're talking about.

A marathon runner, a gymnast, a discus thrower, and a triathlete.

What do you think? Which way round? Okay, well done if you said that a marathon runner would focus on carbohydrate loading, gymnast on timing the protein intake as would a discus thrower, and a triathlete on carbohydrate loading, why is that? Well, marathon runners and triathletes are endurance athletes, aren't they? And they'll be more concerned with making sure they have enough carbohydrates to fuel their events, whereas gymnasts and discus throwers are more power events, much shorter end duration, much more concerned about muscle strength and perhaps hypertrophy and so they'll be more concerned about their protein intake and getting the timing of it correct.

Well done if you've got those the right way round.

Here's the task for this third section of the lesson.

We have Angela here on the left and she competes in shot put, which is a power event.

I'm sure you've had a go at it at some point.

And the two parts of this task are to write a short statement explaining how the optimum weight for a shot putter might be different to other athletes.

And secondly, Angela must do a lot of strength training for her event.

How will the balance and timing of macronutrients in her diet reflect this? Write a paragraph to identify reasons for this.

Okay, so pause the video here, complete those two parts of the task and I'll be back in a minute with some suggested answers.

Okay, so we wanted you to write a short statement explaining the optimum weight differences for shot putters and other athletes.

So things you might have said, shot putters require a greater muscle mass than most other athletes, not all but most.

So they can exert the maximum force on the shot and throw it as far as possible.

Now they have greater, lower, and upper body strength than most athletes.

This means they tend to have much higher optimum weight than a marathon runner.

For example, who needs to be light in order to be energy efficient.

So we made a comparison there to a different type of athlete.

So yes, shot putters if you see them, they're always very, very strong people to give the shot the most force it possibly can.

Second part, Angela must do a lot of strength training for event.

How will the balance and timing of macronutrients in her diet reflect this? Write a paragraph.

So you should have said something along the lines of Angela will need more protein in her diet than the average balanced diet.

This is to provide the protein required for protein synthesis and to allow the muscles to grow and repair.

Her training will cause microtears in her muscles, so she should attempt to consume protein as soon as possible after training to ensure a quick recovery, ideally within an hour, which is known as the golden window.

Well done if you've got those notes in your answer.

That brings us to the fourth and final section.

This one's called understanding the role of hydration.

So keeping hydrated is one of the most important considerations for any athlete.

Being hydrated means the body has the correct amount of water in the cells, the tissues, and organs to function correctly.

Not maintaining your hydration and becoming dehydrated can have several negative consequences on your performance.

The average recommended daily intake is 2.

5 litres of water for men and two litres for women.

I wonder if you drink that much, many people don't.

So consequences of dehydration.

Well, it reduces your ability to sweat and that's linked to where your core temperature will increase.

You'll have low energy levels and you will fatigue quickly when you try and do something like exercise.

It will impair your cognitive function.

It may lead to headaches and dizziness and impaired muscle function.

So loads of reasons why we want to avoid dehydration there, isn't there? Another consequence is that the blood becomes more viscous, which means it's thicker.

And as a result of that, the heart must work harder and faster to pump the viscous blood.

Imagine you're having to push something thicker than it normally is.

That means the blood pressure increases and the amount of oxygenated blood being pumped to the working muscles is reduced because it's just not getting there as fast as it should.

Quick check for your understanding.

Which of these are possible consequences of dehydration that we've just talked about? Is it A, blood is less viscous? B, core temperature increases? C, more sweating? Or D, dizziness? Possible consequences.

What do you think? Well done if you said B and D, core temperature will increase and you might suffer from dizziness.

Okay, so how can athletes maintain their hydration levels? Because it's very clearly important that they do maintain hydration even when they're exercising.

Well, they can do something called pre hydration, which is making sure they're really hydrated in the hours leading up to the performance.

Then they can try and keep hydrated by drinking during breaks or even sometimes during the performance.

If you think about a cyclist, you'll often see them take a water bottle off their bike, drink and then put it back.

So they're lucky that their sport allows them to have the opportunity to drink during the event itself, which not every sport does.

And being sure to rehydrate really quickly after the performance.

You'll see a lot of performers in different sports quickly grab a bottle of water as soon as they finish their event.

Quick check for understanding.

Is it true or false? The only time athletes need to worry about hydration is during the performance.

Is that true or false? That's false, isn't it? And why is that false? Well, athletes should ensure they are pre hydrated before any performance and also focus on rehydrating afterwards.

Otherwise, they may suffer the negative consequences of dehydration.

You don't want to just be worrying about it during that might be too late.

Here's the task for this part of the lesson on hydration.

So Jasmine is hoping to complete an Olympic triathlon in a time of three hours.

And I want you to identify three strategies she can use to maintain her hydration levels.

There may be a clue there in the picture.

And then I'd like you to identify three possible consequences if she does not maintain her hydration levels.

Finally, describe how dehydration, if she didn't maintain her hydration levels would impact her performance.

Okay, so first of all, identifying three strategies.

She should pre hydrate, regularly drink water during the event itself by carrying a bottle on her bike as the picture seems to demonstrate.

And also there'll be water stations during the run that she can grab a bottle of water as she runs past.

And she should drink plenty of water after finishing to rehydrate so that when she gets back to training, maybe later in the week that she's hydrated.

Second part of the task, you might have said.

It will reduce the ability to sweat, core temperature might increase.

She might have low energy levels or fatigue quickly in the race.

Her blood might become more viscous.

Her cognitive function might be impaired.

She doesn't think very well, make good decisions.

Her muscle function may be impaired so she starts to struggle to move properly.

She might suffer from dizziness or headaches.

Well done if you said some of those, three out of that list.

And the final part was to describe how dehydration would impact her performance.

You might have said dehydration will have a negative effect on Jasmine's performance as it is unlikely she will perform as well as she hopes to.

She had that goal where she wanted to complete the racing within three hours.

It's unlikely she will do that if she is dehydrated.

It's likely she'll get tired instead before the end and struggle to move well because her muscles are impaired or think straight because her cognitive function is impaired.

Well done if you've completed the three parts of that task in a similar way to myself.

Okay, here's the summary, follow the summary with me.

A balanced diet is vital for health.

This means ensuring you consume enough macronutrients, micronutrients, and fibre for the benefit they provide.

Optimum weight is subject to a number of factors.

Different sports or activities have different optimum weights according to their demands.

Certain activities will also require different diets to ensure the athlete has the right nutrition to train and perform optimally.

For example, carbohydrate loading for endurance athletes.

Now hydration is another important factor to consider.

Dehydration has several negative consequences for performance and athletes should manage hydration levels before, during, and after participation.

Okay, so I really hope you've enjoyed that lesson.

It's a fascinating subject because everybody eats every day and there's lots of things we should learn about how we fuel ourselves correctly with the right kind of nutrients.

And perhaps you've learned a little bit today about how you might fuel yourself for the sports that you enjoy participating in and perhaps a little bit on what the optimum weight is for the type of activity that you perform as well.

So some really relatable ideas that we can all take something from.

Certainly, I enjoy going back over this topic because of that.

Okay, look forward to seeing you in another lesson soon.

Bye-bye.