Lesson video

Hello everybody.

Welcome to this lesson called Components of a Balanced Diet.

This is from the Health and Wellbeing Diet and Nutrition Unit.

My name is Mr. Brim and I can't wait to lead you through this lesson in which we're going to delve deeper into some really important information.

We're going to look at what it is we should be consuming every day in terms of food and drink to optimally energise us for all those activities that we include in our day, especially those physical activities and sports that you might take part in.

Let's begin, all right, so by the end of today's lesson, you should be able to explain the importance of a balanced diet and hydration and how it supports overall health and performance.

Here are your keywords.

They are balanced diet.

Now it's important that you know the definition here of a balanced diet.

So it's a diet that contains the correct proportions of carbohydrates, fats, proteins, vitamins, minerals and water necessary to maintain food health.

We also have carbohydrate, protein, energy and hydration.

Pause the video here if you'd like to look at those in more detail.

It's a three part lesson.

The first part is called describe the need for nutrients.

So let's get going.

Jacob's question to you is, which type of food will provide you with all the nutrients your body needs if you eat it? Which is that super food out there, which if we just ate this food, it would give us all the nutrients we could possibly need.

What do you think? Well, actually it was a trick question because there is no single food that contains all the nutrients the body needs, and that means we need to eat a balanced diet with different food types to provide suitable nutrients, vitamins and minerals.

Aisha says, have a look at this food label for a medium sized banana.

Do you know what the three missing words are? I wonder if you ever had a look at the nutrition label, which you'll find on the side of packets and boxes of cereal and pretty much everything you eat.

Well those three words are carbohydrates, protein and fat.

And they're the names of the three nutrients our body needs the most.

And we're gonna look at why our body needs those three in a short while.

So beginning with carbohydrates, carbohydrates are the body's preferred source of energy, okay? And around 55 to 60% of our calories should come from carbohydrates.

Now, in physical activity we will use carbohydrates for energy for both aerobic and anaerobic activities.

So it's really important that we're eating plenty of carbohydrates, hence the 55 to 60% of our calories coming from carbohydrates.

Now they come in two forms. I wonder if you knew this already.

Complex and simple.

Let's start with looking at complex.

So good sources of complex carbohydrates.

One of them is pasta.

I wonder if you can think of any more before I reveal a few more.

Well, potatoes, bread and rice are also good sources of complex carbohydrates.

So what do complex carbohydrates do? Well, once they're digested by the body, they're stored in the muscles as something called glycogen and they can provide energy over a long period of time.

So when our body needs to move, it will go to the muscles and use those glycogen stores to provide energy.

Okay, now we said there are complex and simple.

Now simple carbohydrates are what we might call instant energy because they're sugars which are quickly digested and absorbed.

They're not stored in the muscle like complex carbohydrates.

They are instantly available once they've been digested.

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

Let's have a look at some natural sources.

Fruit and honey, they're both natural sources of simple carbohydrates, whereas chocolate and refined sugar are processed sources of simple sugars, okay, or simple carbohydrates.

The fruit and honey, of course they will come with added nutritional value, whereas chocolate and refined sugar don't have much more nutrition in them other than the simple carbohydrate.

So fats are also a source of energy.

So carbohydrates are the body's preferred source, but fats also a source of energy and the body uses fat for energy during low intensity and long duration activities, particularly if carbohydrates stores have been used up.

So if all that glycogen in the muscle has been used, the body will switch to using fats as an energy source.

Now we have two different types of fat we're going to look at here.

We have unsaturated fat, which are healthy fats and you can find that in things like olive oil, avocado and fish.

There are also what we call saturated fats and they are unhealthy sources of fat and you should limit the amount of these that you consume.

Things like butter and snack foods contain a lot of saturated fat.

The kind of fat as I said, that you want to be trying to avoid eating too much of.

Now Jacob says, shouldn't we avoid eating fat? That's an idea that a lot of people have.

Isn't it that we shouldn't be eating fat because fat makes you fat.

What do you think? Well, hopefully judging by the previous slides, you'll realise that actually fats get a bad reputation, but they play an important role as part of a healthy, balanced diet.

And in fact, around 25 to 30% of your daily calories should come from fat sources.

So fat rich foods are calorie dense, which is why perhaps people think we should avoid eating them.

And why you find fat-free yoghourts for example, each gramme of fat contains more than double the calories of a gramme of protein or carbohydrates.

That means that fat rich foods should be eaten in moderation to avoid a calorie surplus.

If you eat lots of fat rich foods, it would be very easy to quickly get to the amount of calories you need in a day, much more so than if you're eating carbohydrate and protein rich foods.

And this diagram sort of shares with you how it looks in terms of the calories in one gramme of fat being nine calories.

Whereas one gramme of protein or one gramme of carbohydrate will give you four calories.

So more than double the calories in the same weight of food.

Check for understanding.

Is this true or false? A fat-free diet would be ideal for everyone.

What do you think? That's false, hopefully you know that.

Why is that? Well, fats are an important energy source as well as playing other important roles in keeping the body healthy.

Fat should be included in a balanced diet and provide 25 to 30% of our daily calories.

So if you ever hear somebody saying you shouldn't eat fat, you now know that actually fats are a very important part of a balanced diet and they shouldn't be avoided, just kept in moderation.

So that brings us to the third of our main nutrients and protein should make up the remaining 15 to 20% of our calorie intake.

Protein occasionally is used to provide us with energy, but actually that's really the job of carbohydrates as we know.

And then perhaps secondary, it's the role of fats.

But protein can play a small role in providing us with energy.

But really their main role and their very important role is in growth and repair of muscle tissue.

That means it plays a vital role in recovery from exercise.

So if you've done a hard session of exercise, you need protein to help you recover.

What are good sources of protein, meat, fish, nuts and eggs.

As you can see a variety, not an awful lot of options there for vegans, but vegans can find different types of protein source as well.

So we've had a look at the three different nutrients.

This is roughly how it should balance out then in terms of the calories provided in your daily diet.

So carbohydrates should be around 55% of your daily calorie intake.

Okay, important energy source and therefore you can see over half of your calories should come from carbohydrates.

Fats should be roughly around 30% and protein around 15%.

Now in addition to those three main nutrients, carbohydrates, fats and protein, there is also a need for smaller amounts, much smaller amounts of vitamins, minerals and fibre 'cause they play important roles too.

They play an important role in keeping the body healthy and functioning properly.

So have some examples of how they might do that.

So calcium helps us to maintain strong teeth and bones.

Iron is really important in haemoglobin formation and hopefully you understand how important haemoglobin is in transporting oxygen around the body.

And fibre plays a really important role in maintaining your digestive function and managing your blood sugar levels.

So important roles there in the maintenance of a healthy body.

Quick check for your understanding.

We've talked about the balance of nutrients.

I'd like you to tell me which of these best represents the ideal balance of nutrients.

Is it A, B, or C? With P standing for protein, C for carbohydrates and F for fats.

Well done if you recognise C, yes, of course we've got around 55% of carbohydrates there, haven't we? Around 30% fat and 15% protein.

The others were slightly out of balance there with less carbohydrates than we need and perhaps too much protein or too much fat.

Well done if you said C.

Okay, now here's the task for this part of the lesson and we are introducing you to Alex.

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

So lots of demand on his body and lots of calories needed by the looks of things.

Now he makes himself this tuna salad that you can see on the left consists of a tuna steak, lettuce and tomatoes.

What I'd like you to do is say, how well does this meal seem to meet the recommended balance of carbohydrates, fats and protein? And then write a sentence for each of those nutrients.

Secondly, I'd like to suggest one change to the meal which would make it even better nutritionally to suit Alex's needs, bearing in mind that he's doing all this circuit training, pause video here and then rejoin me for some suggested answers after you've completed the tasks.

Okay, our tuna of salad, what did you say about the three different nutrients? Let's start with carbohydrates.

Well there isn't a good source of complex carbohydrates here is there? And that should provide 55 to 60% of your daily calories.

So the fact that's missing is quite worrying for Alex, protein, the tuna steak is a really good source of protein.

Seems to be plenty of protein for growth and repair and fats, while tuna and fish are good sources of healthy unsaturated fats.

So that was the first task.

Secondly, I'd like you to make some suggestions on how you might change it.

So this meal does provide Alex with some good sources of protein and healthy fats.

He's gonna need that protein for recovery from his training and for growth and repair and also fats for energy.

However, there is a lack of carbohydrates in the meal which Alex is going to need plenty of for energy to complete his circuit training.

If he's working as hard as it sounds, he's going to need lots of carbohydrates stored as glycogen in his muscles to help him to complete his circuit training.

So he would benefit from adding a portion of complex carbohydrates such as rice.

So hopefully you recognise how Alex's meal has a couple of those nutrients in good number, but actually we're really missing that carbohydrate there.

Well done if it did.

That brings us to the second part of today's lesson and we're explaining dietary needs for different activities.

Okay, Alex has a question for you.

The average calorie needs for a female is 2000 calories per day.

Do you think that differs for men? Well yes it does.

The approximate recommended intake for a male is 2,500 calories and that's largely because, well we know that BMR is affected by height and weight and generally males are taller and heavier than females and that would result in having a higher BMR and therefore needing more calories throughout the day.

Alex's question now is if that's for the average person, what about athletes? So what do you think about that? What's your prediction? Well here's a professional footballer, they're gonna need an average of about 3,200 calories per day, okay? Very large increase on the average person, isn't it? And that can be put down to the fact that they are going to be training most days or possibly playing one or two times a week in a game and therefore of course they're going to be using more energy and if they want to stay in energy balance, they need to consume more calories.

Here's a great example.

So a tour cyclist, you might have heard of the Tour de France, a cyclist in the Tour de France burns on average of 6,000 calories per day, but it can go up to 8,000 calories per day if they're doing the mountain stage where they're racing up the side of a mountain up to the top where the finish line is, 8,000 calories per day.

An incredible number.

So a quick check for your understanding, is this true or false? The more active your day is, the more calories you need to consume to find an energy balance.

Is that true or false? What do you think? That's true, why is that? Well, of course activities will burn more calories and that depends on their intensity and duration.

You must fuel this activity by consuming the same number of calories in a balanced diet to remain in energy balance.

So again, going back to that to de France cyclist who's getting 6,000 calories worth of activity in every, they're going to need to replace that with 6,000 calories worth of food and drink.

Lucas's question is how about what an athlete eats? So we've talked about calories, now we're thinking about the nutrients that you need in a diet.

Does that differ from the norm too he wonders.

What do you think about that? Maybe pause the video here while you do have a think about what athletes would eat and whether that's different from the 55% carbohydrates that we looked at earlier or the 30% fat or the 15% protein.

What do you think? Well let's have a look at that chart that I just described.

We've seen this a couple of times now, haven't we? Lucas says that we know this is the approximate balance of nutrients for people in general, and then he's shown us two new charts, one on the bottom left and one on the bottom right.

Who do you think these other diets might suit? Have a closer look.

Maybe pause a video, have a closer look and think who would suit these two different nutrient balances? Okay, well the one on the bottom left would suit somebody who's a power athlete who does a power event and the one on the bottom right would suit an endurance athlete.

We're gonna have a look in greater detail about why that's the case.

Let's think about the power athlete first then.

So Lucas is back and he says, what is it about the combination of nutrients in that graph there that would suit a power athlete? What do you think knowing what you know about those three nutrients? Well, power athletes spend a lot of their training doing activities such as weight training or plyometrics and they're aiming to achieve hypertrophy of the muscles.

So because they are essentially damaging the muscles and in a good way, okay, they're causing micro tears in the muscles through this weight training or plyometrics and those micro tests need repairing, okay? And so a power athlete by focusing on weight training or plyometrics will need more protein than the normal person to grow and repair muscles and create the adaptations they need to lead to hypertrophy.

Here's a quick check for understanding, which of these snacks would suit someone who regularly does weight training more than someone who does not? Is it A, a protein shake, B cookies or C and apple? Well then if you said protein shake, of course, now protein shakes have become very popular with people who do weight training for exactly the reason we've just discussed.

People who do weight training or power athletes who do things like weight training or plyometrics, they need to increase their protein intake and protein shakes have become a really convenient way of upping the amount of protein that you can consume.

Now let's think about why this graph on the left there suits an endurance athlete.

And Lucas says, how do we explain endurance athletes' extra intake of carbohydrates? Because that's the main thing we can take, isn't it? From that graph, the amount of carbohydrates as shot up from 55 to 65%.

So what do you think about that? Well, endurance events are long in duration and they have limited options for refuelling.

If you are a marathon runner for example, you might take a couple of gels with you energy gels and they are simple carbohydrates which are absorbed quickly and give you a boost of energy, but you don't get to refuel too often along the way while you're doing this marathon for like two, three or four hours perhaps.

And so endurance athletes try to ensure they have as much energy and that's carbohydrates, but stored as glycogen from complex carbohydrates in their muscles as possible so that they can perform at their best.

So they want to begin the race knowing that their muscles are packed with as much glycogen as possible ready to be used for energy.

This is the task for this middle section of the lesson.

I'd like you to look at this and briefly explain the dietary needs of these three athletes that you can see, a power lifter, a golfer and a boxer.

I'd like you to estimate and just have a good estimation of how much their daily calorie intake might differ from the recommendation of 2,500 calories for males and 2,000 for females.

And how might the balance of nutrients differ from the norm.

Also, imagine if we were creating one of those graphs, one of those pie charts for these three athletes, what might that look like? Okay, so pause the video here and answer that task.

So pause the video here and answer that task and then come and rejoin me and I'll talk through some of the answers.

All right, let's begin with the power lifter.

What might you have said? Well, power lifters work hard in training to increase their muscle mass.

They generally have a high body weight because you need to be quite large to be able to move the weights.

Essentially, their competitions are all about who can move the most weight and you're not gonna move much weight if you don't weigh quite a lot yourself.

Now this is going to require a calorie surplus, therefore a power lifter will consume between 3,504,000 calories a day to fuel their training and still remain in calorie surplus.

Okay, so if you're going to have muscular hypertrophy and increase your muscle mass and have a high body weight, you need to have a calorie surplus where you're eating a little bit more in terms of calories than you are burning or expending.

That means power lifters must have quite a high number of calories each day around 3,500 to 4,000, which is much higher than the recommendation, isn't it? Now what about their nutrient balance? So that is likely to include more protein.

Hopefully you recognise that, we've talked about this just a few slides back.

More protein is needed to help rebuild muscles after heavyweight training sessions.

Next is a golfer.

Now performance in golf is not really dictated by body weight, okay? Certainly not to the extent of a lot of other sports.

Most people of different shapes and sizes can play golf and be successful.

It's really a game of skill where the body shape doesn't have too much of an impact.

There has been a trend in recent years where some of the male golfers have become quite stocky in terms of putting on muscle.

That's to help them drive the ball further and it's given them a slight advantage.

But generally golf is played by people of all sorts of shapes and sizes and you can be successful, irrespective of what your body shape is.

So the requirements of the sport, if we think about it, you swing the golf club and then you walk to the next shop, neither of which burn a large amount of calories.

So walking along the 18 holes of a golf course might require slightly more calories than the normal recommendations, but not a huge amount.

So golfers might need something like 2,800 calories on a day where they are performing just to stay in energy balance, but not a huge amount.

And because in general, golf is a sport where you can be successful based on skill and not have to train in a particular way to be a certain shape.

A golfer doesn't really need to deviate from the normal neutral balance either.

Final sport was boxing, wasn't it? And many boxers work incredibly hard in training to be in peak condition for their upcoming fight.

They work really hard, this requires a lot of fuel.

Boxers might need to consume up to 5,000 calories per day during their most intense training days.

Because their training is a blend of cardio and strength training, the body is going to require carbohydrates for fuel, plenty of carbohydrates to keep that cardio work going, but also lots of protein for recovery 'cause those muscles are going to be worked hard, these nutrients will certainly be more than the norm.

So well done if you recognised how the diet for power lifters, for golfers and for boxers might differ slightly to suit their sport.

Let's move on to the third and final section of the lesson, which is called understanding the role of hydration.

All right, so keeping hydrated is one of the most important considerations for any athlete.

In fact, any person.

So being hydrated means the body has to correct amount of water in your cells, your tissues and your organs to function correctly, not maintaining your hydration and becoming dehydrated.

I'm sure you've come across that before.

Can have several negative consequences on your performance.

You might be surprised at just how many negative consequences being dehydrated will have on you.

Now the average recommended daily intake is 2.

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

But of course if you are training, working really hard, working in a hot environment, you're going to need more than the recommended daily intake.

Okay, so what are those consequences of dehydration? Believe me, there are a lot and there are all negative.

So you have a reduced ability to sweat because there's not enough water and sweat is essentially water, isn't it? And that will have a result of your core temperature increasing, okay? You'll feel hotter, you'll end up with low energy levels, which certainly isn't something you want to be experiencing very often.

You want to feel as energetic as possible, don't we? Certainly if we're doing physical activity in sport and linked to that is that your fatigue quickly or much quicker than you would've done if you were hydrated.

So if you go for a run, for example, you can likely expect to need to stop a lot earlier than you would've done if you were hydrated.

Impaired cognitive function.

So you can't think straight, you might have headaches or dizziness and impaired muscle function, so your muscles and your ability to move might be impaired, you might not be able to do it as well as normal.

And another consequence is that your blood becomes more viscous.

Now that means it becomes thicker, okay? Imagine if your blood became thicker and as a result of that thick blood, the heart then must work harder and faster to pump the viscous blood.

And that also results in your blood pressure increasing as the heart is working so much harder to push that viscous blood through the arteries and the amount of oxygenated blood being pumped to the working muscles is reduced, your heart is not able to get enough oxygen to the working muscles quickly, and that's why you will fatigue a lot quicker.

Let's check for your understanding.

Let's have a look at these.

Which of these are possible consequences of dehydration? Is it A, that blood is less viscous? B, that core temperature increases, C, more sweating or D, dizziness? What do you think? Well done if you spotted two correct answers there.

B, your core temperature will increase.

And D, dizziness is a possible consequence.

Blood is less viscous was incorrect because it's actually more viscous, which means thicker and more sweating is incorrect because actually you'll have a reduced ability to sweat.

Well done if you said B and D.

Aisha's question is, how can athletes maintain their hydration levels if it's so important? What do you think? Well, we can pre hydrate and pre hydration means that in the hours leading up to the performance, you make sure you drink plenty of water so that the moment you begin your activity you are as hydrated as possible.

So keeping hydrated by drinking during breaks as we can see in the image or sometimes during the performance.

So people who cycle perhaps might have a bottle attached to the bike and they can drink while they're actually performing.

In a lot of sports you can't drink while you're performing, but you might be able to during a break.

And then being sure to rehydrate quickly after the performance because of course in most cases you might be training again in a couple of days or perform again in a couple of days.

So as soon as you finish a performance where it might have worked you so hard that you're a little dehydrated, you very quickly be sure to rehydrate once the performance is over.

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

That's false, isn't it? And why is that false? Hopefully you know that athletes should ensure they are pre hydrated before any performance and also focus on rehydrating after the performance.

Otherwise they may suffer all those negative consequences of dehydration and we certainly want to avoid those.

This is the task for this final section of the lesson here we have on the left Jasmine and Jasmine is hoping to complete an Olympic triathlon in a time of three hours.

First part of this task is to identify three strategies she could use to maintain her hydration levels and there is a clue there in the picture, isn't there? Secondly, identify three possible consequences if she does not maintain her hydration levels.

And thirdly, describe how dehydration would impact her overall performance and perhaps her attempt to complete this Olympic triathlon in a time of three hours.

Pause the video here, get those three parts of the question answered, and then come and rejoin me for some suggested answers.

Okay, let's have a look then, shall we? So the third part was to identify three strategies.

What should she be doing? You might have said that she should pre hydrate in the buildup to the race so that she's fully hydrated before she starts.

She should take regular drinks of water by carrying a bottle on the bike as the image shows, and also any water stations during the running part of the triathlon.

She should drink plenty of water afterwards to make sure that she rehydrates.

Okay, if she's serious about her triathlon, it's likely that she'll be training again for the next one within a few days, and so she should make sure that she's recovered by rehydrating.

Secondly, identify three possible consequences.

While we're talking about dehydration, aren't we here? So the reduced ability to sweat, you could have had core temperature increases, low energy levels, fatigue quickly during the race.

Her blood may become more viscous, her cognitive function might be impaired, her muscle function might be impaired, or she might suffer dizziness or headaches.

You only needed to give three of those but there's certainly a long list there that you could have chosen from.

Finally, describe how dehydration would impact her performance.

Things you might have said.

Well, dehydration will have a negative effect on Jasmine's performance.

It's unlikely she will perform as well as she hopes to.

Certainly not going to reach that three hour goal if that was a challenging target for her.

Likely she will tyre before the end, struggle to move well or think straight.

She might make some bad decisions because cognitive function has been impaired.

So well done if you manage to answer the three parts of that question.

Recognising how important hydration is to Jasmine in a similar vein as to how I did, and that brings us to the summary on this lesson called Components of a Balanced Diet.

Would you like to read along with me? So there is no single food that contains all the nutrients the body needs.

Hence, a balanced diet should include a variety of food sources to provide us with nutrients, vitamins and minerals that we need.

Carbohydrates are the body's preferred source of energy.

While fats provide energy for low intensity or long duration activities, protein is vital in growth and repair of muscles.

And for most people, a balance of 55 to 60% carbohydrates, 25 to 30% fats, and 15 to 20% protein is about ideal.

Calorie requirements are dependent on the activity levels and athletes may need to eat more of a specific nutrient to meet their energy needs.

Finally, hydration is vital to performance because becoming dehydrated has several negative effects on the body's ability to perform physical activity.

Okay, so we've managed to fit a lot in there, haven't we? About how we should eat and drink to make sure that we've got the right level of energy that we need for all those physical activities and sports.

As I said at the beginning, this is vital information.

This is not something just for GCSE PE students, that's for sure.

This is the kind of thing that everybody should know about.

How do I fuel myself every day to make sure that I'm maintaining my hydration levels, I am having enough energy to get about my daily tasks and maybe even a little bit extra energy to make sure that you can be physically active or do some sport at some point.

Great messages to share with anybody who wants to listen to it.

I look forward to seeing you in another lesson soon.

Bye-bye.