Lesson video

Hello, everybody, it's Mr. Broome here with a lesson called "A Balanced Diet" from the "Health and Wellbeing Diet and Nutrition" unit.

Hope you're looking forward to this lesson.

It's a lesson that's really relevant to every single person who's alive today because we all consume calories, we all expend calories, we all should know exactly how we should be eating to make sure that we're fueled so that we can do as much activity as possible and that we can lead healthy, active lives.

So something you're really going to enjoy today, I'm sure.

Let's get started.

All right, then.

So by the end of today's session, you should be able to explain the importance of a balanced diet and how it supports overall health and performance.

Here's your keywords for today.

Balanced diet, carbohydrate, protein, energy.

In particular, pay attention to that definition there of balanced diet.

We've got a two-part lesson today.

The first part is called describe the need for nutrients.

So let's begin.

Jacob's question from the off, is which type of food will provide you with all the nutrients your body needs if you eat it? Is there a superfood out there that does that for us? "Well, it's a trick question.

Sorry," says Jacob.

Because there is no single food that contains all the nutrients the body needs.

We need lots of different types of nutrients.

And as I said, there is no single food that contains them all.

That's why we need to eat a balanced diet with different food types, providing the nutrients, vitamins, and minerals that we need to nourish us, to give us energy and to keep us alive.

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

Do you know what the three missing words are? There with the question marks in purple.

Have you ever looked at a nutrition label before? And what are those words? Well, they're the names of the three nutrients our body needs the most.

They are carbohydrates, proteins, and fat.

So carbohydrates are the body's preferred source of energy.

It's the go-to source of energy when the body needs energy.

For that reason, around 55 to 60% of our calories should come from carbohydrates.

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

Okay, so as you can see, really important source of energy.

Now, they come in two forms, carbohydrates.

We have complex carbohydrates and we have simple carbohydrates.

Let's think about the complex carbohydrates first.

Good sources of complex carbohydrates are pasta.

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

I wonder if you thought of potatoes, bread, and rice.

All four of those are good sources of complex carbohydrates.

So a little bit more about complex carbohydrates because they're very important.

Once digested, the complex carbohydrates are stored in your muscles as something called glycogen and they provide energy over a long period of time.

So the body will go to that stored glycogen when it needs energy to move.

Simple carbohydrates are different.

They are like instant energy because they're sugars.

When you digest them, it's really quick and they're absorbed very, very quickly into your bloodstream.

So sources of simple carbohydrates are, well, some of them are natural and some of them are processed.

I wonder if you could think of a simple carbohydrate source before I reveal some.

Well, fruit and honey are two of the natural sources of simple carbohydrates.

And chocolate and refined sugar are two examples of processed simple carbohydrates.

Generally, the natural sources of carbohydrates are much better than the processed because they also contain different nutrients, whereas chocolate and refined sugar are not very nutritious beyond the very quick boost of energy you'll get from the sugars within them.

Now, fats are also a source of energy.

The body uses fat for energy during low intensity, long duration activities, particularly after carbohydrates stores have been used up.

So let's say you go for a really long run.

At some point, your muscles will run out of glycogen stores and so they will switch to using fat for energy instead to keep you going.

Now, there are unsaturated fats which are healthy.

These sources are olive oil and avocado and oily fish.

There are also unhealthy sources of saturated fat.

So you might see the difference on a food label between unsaturated and saturated.

Unsaturated fats are healthy, saturated fats are unhealthy and they include things like butter and you find saturated fat in lots of snack foods.

Now, Jacob is sharing quite a common idea that shouldn't we avoid eating fat? Isn't fat bad for us? Doesn't fat make us fat? Well, actually no, fat gets a bad reputation, but they play an important role in part of our healthy balanced diet.

And actually, 25 to 30% of our daily calories should be from fat sources.

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

So eating 100 grammes of a really fatty food will give you almost double the number of calories as eating 100 grammes of something that's carbohydrate or protein.

And you can see that here in this diagram where one gramme of fat equals nine calories, whereas a gramme of protein or carbohydrate would give us only four calories.

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

What do you think That's false.

In answer to Jacob's question earlier, shouldn't we avoid eating fat? The answer was no, wasn't it? Because actually, fats are an important energy source as well as playing other important roles in keeping the body healthy.

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

Okay, so if you hear people saying you shouldn't eat fat, they're wrong because fats are very important for the body.

Now let's think about protein, the third of our nutrients.

Protein should make up the remaining 15 to 20% of our calorie intake.

Now, even though this play a small role in providing us with energy, remembering that carbohydrates are our main source of energy and then fats take over at some point when perhaps we've run out of carbohydrates, protein give us a little bit of energy if we really need them to.

However, their main role is in growth and repair of muscle tissue, meaning it plays a really vital role when we recover from exercise and we need to repair muscle tissues that are being damaged.

What are good sources of protein? I wonder if you can think of any before I reveal them.

Well, meat, fish, nuts, and eggs.

There are lots of good sources of protein, perhaps a little bit more difficult for those who are vegetarians or especially vegans to find good sources of proteins, but they are out there.

Here's the approximate balance of nutrients that are required in your daily diet.

We've had a look at this, haven't we already, but here it is in graphical form with a pie chart.

So carbohydrates around 55, fats around 30%, protein around 15%.

Okay, so in addition to the three main nutrients of carbohydrates, proteins, and fats, we definitely require those, but we also need a smaller amount of vitamins, minerals, and fibre.

That's because they each play an important role in keeping the body healthy and functioning properly.

For example, you need to get calcium in your diet for strong teeth and bones.

You need iron in your diet because iron forms haemoglobin.

Can you think of what haemoglobin does in the body? The picture there hopefully is a bit of a clue to that.

Fibre especially will help your digestive function.

Okay, keep you regular and also regulate your blood sugar levels.

Okay, so really important roles that we need these, these smaller amounts of vitamins, minerals, and fibre to keep us going, to keep us healthy.

Quick check for your understanding.

Which of these graphs best represents the ideal balance of nutrients with P standing for protein, F for fats, and C for carbohydrates? Which of those graphs is the best balance of nutrients? Well, it was C, wasn't it? Because C represents around 55% of carbohydrates, 30% of fats, and maybe 15% of protein, roughly around that balance.

The other two, too much fat perhaps in that first one.

In A, too much protein.

A very small amount of carbohydrate, isn't there, with option B, and we really need carbohydrate to be much higher so that it can fuel all of our activities.

Well done if you said C.

Here's the task for this half of the lesson.

So we have Alex and Alex regularly go circuit training, which includes lifting weights, lots of aerobic exercise.

He makes himself this tuna salad you can see in the image, consists of a tuna steak, some lettuce, and some tomatoes.

First part of this task is I want you to think about how well this meal that Alex has made seems to meet the recommended balance of carbohydrates, fats, and proteins as we just saw in the check for understanding in image C.

I'd like you to write a sentence about each of those nutrients and how well it's achieved the target of getting them into the diet.

Then I'd like you to suggest one change to the meal which Alex could make to make it even better nutritionally and suit Alex's needs, bearing in mind that he's lifting weights and doing lots of aerobic exercise so he clearly needs lots of energy and also recovery.

Pause the video here and then rejoin me after you've written your answers to those two parts and we'll have a look at some of the suggested answers.

Okay, so part one, what might you have said? Well, carbohydrates, if we look at that meal, there isn't really a good source of complex carbohydrates and we know that they should provide 55 to 60% of our daily calories.

Okay, we're lacking there in carbohydrates and that means a lack of energy.

In terms of protein, tuna steak is a very good source of protein and there seems to be plenty of protein in this meal because it's a big piece of tuna there, isn't it? And fats, tuna is also a good source of healthy unsaturated fats.

So Alex is achieving a good amount of protein and fats in this meal.

So the second part is to sort of do a little bit more analysis and make a suggestion on what Alex could do better with this meal.

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

Now, it's said earlier that he's doing circuit training with weights, so he is gonna need protein to recover from his training for growth and repair.

He's also gonna need fats for energy.

However, this lack of carbohydrates is the big issue really with this meal.

Alex is gonna need plenty of energy to complete his circuit training, but he's lacking the carbohydrates he needs to provide that energy.

So what would Alex benefit from? Well, he would benefit from adding a portion of complex carbohydrates, that could be rice or maybe pasta or potato, but he definitely needs to add some complex carbohydrates into this meal to improve it.

I hope that you recognise that and that was included in your answer.

Well done if so.

That brings us to the second part of the lesson called explain dietary needs for different activities.

So Alex is gonna guide us through a couple of slides here, as he says that the average calorie needs for a female is 2,000 calories per day.

Does that differ for men, he asks? What do you think? Well, it does in fact differ for men.

The average calorie needs for a female or the daily recommended intake is 2,500 calories for the average male.

That's for the average person, notes Alex.

But what about athletes? What do we think? Would an athlete need the average or the recommended daily amount or something different? Well, let's have a look.

A professional footballer who's training most days of the week or playing on a weekend will need an average of 3,200 calories per day.

Clearly, a lot larger amount of calories there, isn't it, than the average recommendation.

And wow, a cyclist in the Tour de France burns an average of 6,000 calories per day.

And on some of the really tough stages where they're cycling up the side of a mountain to the top, they might use up to 8,000 calories on a mountain stage.

An incredible amount of calories.

Is this true or false? The more active your day is, the more calories you need to consume to find an energy balance.

What do you think? True or false? That, of course, is true, isn't it? And why is that? Well, activities will burn more calories depending on their intensity and duration.

You've got to fuel this activity by consuming the same number of calories in your balanced diet to remain in an energy balance.

So every calorie you expend, you must replace by consuming with food or drink.

And that way, you'll remain in energy balance.

Well done if you said true.

Lucas' question is, "How about what an athlete eats? Does that differ from the norm too?" He's thinking about nutrition there and the types of nutrients.

Would an athlete eat different nutrients from the normal person? Well, let's consider it.

Okay, so Lucas is still with us.

And he says, "We know that this graph here on the top left, and we've seen this one a couple of times already in today's lesson, is the approximate balance of nutrients for people in general." The average person should be consuming 55% carbohydrates, 30% fats, 15% proteins in their diet.

However, Lucas says, "Who do you think these other diets might suit?" In the bottom left there, we've got a diet with much more protein, 30% protein.

And in the bottom right there, we've got a diet which has 65% carbohydrates, so much more than the average person would need.

Who do we think these diets might suit? Well, the bottom left diet would suit power athletes and the bottom right diet would suit endurance athletes.

Let's have a look in more detail about why that's the case.

So Lucas says, "What is it about this combination of nutrients that would suit a power athlete?" Before I reveal some answers, maybe you have a little think yourself.

Okay, well, power athletes spend a lot of their training doing activities such as weight training or plyometrics because they're trying to achieve hypertrophy of the muscles.

They want bigger, stronger, more powerful muscles.

So a greater percentage of protein than normal is required because what happens when we do these types of training, weight training, plyometrics, and we're trying to achieve hypertrophy, the muscles actually get some small micro tears in them.

That's deliberate, it's not an injury and they need to repair and repair back stronger than they were and that's why the muscle gets bigger and stronger as the adaptations that they need begin to accrue.

Okay, now a quick check for your understanding.

Which of these snacks would suit someone who regularly does weight training more than someone who does not? Would they benefit from snacking on A, protein shakes? B, cookies? Or C, an apple? Okay, well, we've just talked about this, haven't we? The need for an increase in protein, and protein shakes are one way of getting more protein into your diet quite conveniently and quickly.

So well done if you said A.

Back to those three charts, the one on the bottom right said that endurance athletes need more carbohydrates.

So Lucas says, "How do we explain why endurance athletes need an extra intake of carbohydrates?" What do you think about that? Well, endurance events are long in duration.

They can be hours long, aren't they? And have limited options for refuelling.

Perhaps on a marathon, you might have some energy gels with you, which you can take, but it's not gonna give you a whole amount of energy, certainly not enough to get you around the whole course.

So endurance athletes try to ensure they have as much energy and that's through carbohydrates stored in the muscles as glycogen in their muscles as possible to perform at their best.

They need that energy stored in their muscles before they even begin.

They can't get it during the event.

It has to be already there before they begin.

Otherwise, they're going to get tired, aren't they, quite quickly and run out of energy.

The task for this section, we're gonna look at the dietary needs of three athletes, power lifter, a golfer, and a boxer.

I'd like you to estimate and just have a good, good estimation.

Okay, don't worry about getting it exact.

How much their daily calorie intake might differ from the recommended 2,500 calories for males and 2,000 for females? How might the balance of nutrients differ from the norm also? So thinking about those pie charts again, aren't we? So with a power lifter, a golfer, and a boxer, how might their calorie intake differ and how might their balance of nutrients differ? Pause the video here, write down your answers and then rejoin me for some suggested answers.

Okay, so let's go sport at a time or athlete at a time.

We have the power lifter.

So power lifters work really hard in training to increase their muscle mass.

The bigger the muscles they have, the more likely they are to lift a heavy weight during competition.

They generally have a high body weight to help them move that weight.

This requires a calorie surplus, doesn't it? If we want to get bigger and bigger muscles, we need to have some sort of calorie surplus that takes us beyond the amount of calories we burnt during training and during our daily activities plus our BMR. This will require a calorie surplus.

Therefore, power lifters will consume between 3,500 and 4,000 calories a day to fuel their training and still remain in that calorie surplus.

How about the nutrient balance? Well, they are likely to include more protein than average due to the need to rebuild muscles after heavyweight training sessions, remember those micro tears we talked about are caused by weight training and those micro tears need repairing and they'll be repaired stronger as long as there's enough protein to do so.

How about the golfer now? So golf is not a sport in which body weight really dictates how well you play.

Certainly not to the same extent as other sports.

Lots of people in lots of body shapes and body weights can take part in golf and still play very well.

There has been a movement sort of in male golf to be a little bit bigger and muscly so that they can drive the ball a bit further.

But generally, it's a game of skill rather than something that relies on a physical size to get you through the game.

So the requirements of golf are doing the golf swing and walking to the next shot, neither of which burn a huge amount of calories, do they? Walking an 18-hole golf course can be quite far and may require a small amount of additional calories to the normal recommendations.

So a male may need like 2,800 calories on a day where they're playing an 18-hole course.

But generally, it's roughly around the normal recommendations for golfers.

How about nutrient balances? Well, they don't particularly need to deviate from the norm unless they are one of those golfers who tries sporting a bit of muscle.

In that case, they might need to have a little extra protein in their diet than normal.

But generally, golfers can get away without having to really deviate from the normal recommendations.

Finally, we had boxers.

Boxers work incredibly hard in training.

If you've ever seen them training, they work really, really hard.

They're trying to get into peak physical condition for their upcoming fight, and that requires a lot of fuel.

So boxers may consume up to 5,000 calories per day during their most intense training days.

Their training is a blend of cardio and strength training, so they need lots of carbohydrates for fuel, but they also need lots of protein for recovery.

These nutrients will certainly be more than the normal person consumes.

Okay, so well done if you had a good estimate there on the calories.

Don't worry if you're a little bit out.

I was asking you to really have a guess almost or an educated guess, let's say, about how many calories those athletes would burn.

But hopefully, in terms of the blend of nutrients in their diet, you recognised how each sport perhaps needs a different level of either carbohydrates, proteins, or fats.

Good job if you included all those.

That brings us to the summary for today's lesson on a balanced diet.

Let's have a look at it.

Read it along with me.

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 the minerals that we need.

Carbohydrates are the body's preferred energy source, while fats provide energy for low intensity and long duration activities.

Protein is vital in growth and repair of muscles.

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

Calorie requirements are dependent on the activity levels, with sports and physical activities which are high in intensity and long in duration requiring a greater amount, like the 8,000 calories a Tour de France cyclist on a mountain stage will need.

Finally, athletes need to eat more of a specific nutrient to meet their needs in many cases, isn't it? So thanks for joining me for today's lesson.

I really hope you got something out, that everybody should get something out of this lesson because no matter whether you're doing GCSEPE or not, this is something that we can all apply to our own lives.

Perhaps today you've had a chance to consider how many calories you need for your daily needs and your daily activities, or perhaps you've thought about the blend of nutrients that suit the kind of activities that you do or the way that you train every week.

Lots of information here for everybody to benefit from.

I look forward to seeing you in the next lesson.

Bye-bye.