Most of it is spent doing nothing

Ask anyone where their food energy goes and they will talk about exercise. Running, sport, walking to school. It is the obvious answer and it is mostly wrong. ⚠️ THE LARGEST SINGLE CLAIM ON A PERSON'S ENERGY IS MADE WHILE THEY ARE LYING COMPLETELY STILL, DOING ABSOLUTELY NOTHING, ASLEEP. A body at rest is not idle. It is running a heart that never stops, holding a temperature against a colder room, driving a brain that uses energy at a rate out of all proportion to its size, replacing cells, repairing tissue, keeping a kidney filtering and a gut working. ⭐ NONE OF THAT IS OPTIONAL AND NONE OF IT CAN BE SWITCHED OFF. That resting cost has a name, and it is the foundation of this whole part of your course. ⭐⭐ SO THINK OF IT AS A BUDGET RATHER THAN AS A DIET. THE BODY HAS A BILL TO PAY EVERY DAY, MOST OF IT ARRIVES BEFORE ANYBODY GETS OUT OF BED, AND THE PART A PERSON ACTUALLY CHOOSES IS THE SMALLER PART. Once you see it that way, several things stop being arbitrary. WHY DO TWO PEOPLE THE SAME AGE NEED DIFFERENT AMOUNTS? Because the resting bill differs. A bigger body has more tissue to keep alive. More muscle costs more to maintain than the same weight of fat. The bill is set by the body, not by the person's intentions. WHY DO NEEDS CHANGE THROUGH LIFE? Because growth, repair and pregnancy are all paid for out of the resting part, not out of the activity part. ⚠️ AND WHY IS "JUST MOVE MORE" A WEAKER LEVER THAN PEOPLE EXPECT? Because it is being applied to the smaller share. One question to carry through the rest of this module: is this a claim on the resting part of the budget, or on the part that gets chosen?

Where the daily budget actually goes

Three claims on one day of energy. The first is the one nobody sees and the largest for most people.

Tap what the budget idea actually claims

Tap the TWO statements that follow from most of the budget being spent at rest.

Two people of the same age can need different amounts because their resting bills differ
Activity is best handled as a multiplier applied to the resting figure rather than as a separate total
The largest share of a typical person's daily energy is used during deliberate exercise
Growth during childhood is paid for out of the activity part of the budget

Same age, different bills

Two people are the same age, eat similarly and do similar amounts of activity, yet one needs noticeably more energy each day than the other. What is the most likely explanation?

Their resting bills differ, because body size and the proportion of muscle to fat both change how much energy a body uses simply staying alive
One of them must be putting more effort into their activity than they realise
One of them must digest food much less efficiently than the other
Two similar people should not differ, so one of the measurements must be wrong

The five terms this part rests on

Five terms, each defined by what it is. How they combine is the work of the steps that follow.

Match each situation to its effect on the budget

A child going through a period of rapid growth
Someone who has gained muscle over a year of training
An adult who moves from manual work to a desk job
Somebody recovering from an illness
Working outdoors through a genuinely cold spell

Raises the resting bill, because building new tissue is paid for out of it
Raises the resting bill permanently, because that tissue costs more to maintain than the fat it replaced
Lowers the multiplier applied to the resting bill, without changing the resting bill itself
Raises the bill temporarily, because repair is being paid for on top of normal upkeep
Adds a small extra claim, because holding temperature against the cold costs energy

Two that follow from the budget

Select the TWO statements that follow from treating energy requirement as a resting bill scaled by activity.

A person's daily requirement is better worked out by scaling their resting figure than by adding up their activities
Changes in requirement across life stages come mostly from changes in the resting bill rather than in how much people move
Since the activity part is the part people choose, differences in requirement between individuals are mainly a matter of willpower
Kilocalories and kilojoules measure different things, so a label giving both is giving two separate figures

Something revision guides get wrong about your board

If you revise this topic from a general guide or from a friend on a different exam board, you will meet a set of percentages: what share of energy should come from each of the three macronutrients. ⚠️ BE CAREFUL WITH THEM. ⚠️⚠️ THOSE FIGURES ARE CURRENT NATIONAL DIETARY GUIDANCE, PUBLISHED BY THE GOVERNMENT'S SCIENTIFIC ADVISORY COMMITTEE ON NUTRITION. THEY ARE NOT YOUR SPECIFICATION'S CONTENT. Another major board does name them and examines them. Yours does not. ⭐ SO IF YOU USE ONE, SAY WHERE IT COMES FROM IN THE SAME SENTENCE. Written as "current national guidance recommends...", a figure is a strength. Written as though your course required it, it is a claim you cannot support, and it takes up space that should have gone on something that does earn marks. ⚠️ AND THE SAME CAUTION APPLIES TO THE SET OF TIPS FOR HEALTHY EATING YOUR SPECIFICATION MENTIONS BY NAME. IT NAMES THE FRAMEWORK. IT DOES NOT LIST THE TIPS. Do not reproduce a list from memory and present it as required content. What your board does ask for is the reasoning, and that is worth more anyway. ⭐ BE ABLE TO SAY WHAT SETS A PERSON'S RESTING BILL, and why it differs between two similar people. ⭐ BE ABLE TO SCALE IT by how active somebody is, and to say why activity is a multiplier rather than an addition. ⭐ BE ABLE TO SAY WHICH WAY THE BALANCE IS TIPPED AND WHAT FOLLOWS, in mechanical terms, without moralising about anybody. ⭐ AND BE ABLE TO EXPLAIN WHAT EACH MACRONUTRIENT IS CLAIMING THE ENERGY FOR, which is the next card. ⚠️ ONE LAST HABIT. DO NOT INVENT A NUMBER. A daily requirement, a recommended intake, a figure for how common a condition is: if you are not certain, leave it out and explain the mechanism instead. The mechanism is what is being marked.

Three claims on the same budget

Not three kinds of food. Three different claims on one day of energy, only one of which is primarily a building material.

What a shortfall does to protein

Somebody takes in noticeably less energy than their daily bill over a long period, while still eating protein-containing food. Why can their repair and growth still suffer?

Because the body will burn protein as fuel to cover the shortfall, so building material is spent on energy instead of on repair
Because protein cannot be absorbed properly when total intake is low
Because the body has no way of storing protein for later use
Because the protein they are eating must be of low biological value

Scale the resting bill

A worked example with figures supplied. A person has a basal metabolic rate of 1,500 kcal per day and a physical activity level of 1.6. Work out their total daily energy requirement, then subtract the resting bill, to find how many kilocalories are accounted for by everything other than staying alive.

Two people, two budgets

Take two adults of the same age and follow the arithmetic rather than the assumptions. THE FIRST HAS A LARGER BODY WITH MORE MUSCLE ON IT, AND WORKS AT A DESK. Their resting figure is high, because there is more living tissue to keep running and muscle is expensive to maintain. Their activity multiplier is low, because most of the day is spent sitting. THE SECOND IS SMALLER AND LIGHTER, AND DOES PHYSICAL WORK ALL DAY. Their resting figure is lower, because there is less tissue to keep going. Their multiplier is high. ⚠️ YOU CANNOT SAY WHICH OF THEM NEEDS MORE WITHOUT DOING THE SUM, AND THAT IS THE POINT OF DOING IT THIS WAY ROUND. A big resting figure with a small multiplier can easily land near a small resting figure with a large one. ⭐ NEITHER THE BODY NOR THE JOB SETTLES IT ALONE. Now watch what happens when something changes, because this is where the reasoning earns marks. THE DESK WORKER TAKES UP REGULAR TRAINING AND, OVER A YEAR, GAINS MUSCLE. ⭐ TWO THINGS MOVED, NOT ONE. The multiplier went up while they were training, and the resting figure went up permanently, because that new tissue has to be maintained every day whether they train or not. THE MANUAL WORKER CHANGES TO AN OFFICE JOB. Their multiplier falls straight away. Their resting figure does not change at all, because their body is the same body it was the week before. ⚠️ SO THEIR REQUIREMENT DROPS, AND NOTHING ABOUT THEM HAS BECOME WORSE OR LAZIER. THE BILL SIMPLY CHANGED, AND THE HABITS BUILT AROUND THE OLD BILL NO LONGER MATCH IT. And one more, because it is the case the specification cares about most. A TEENAGER GROWING QUICKLY HAS A RESTING FIGURE RAISED BY THE GROWTH ITSELF, since new tissue is built out of that part of the budget. They may need more than an adult of the same size who has finished growing, while doing no more activity at all. ⭐ WHICH IS THE WHOLE ARGUMENT OF THIS MODULE IN ONE SENTENCE: THE DEMAND CAME FROM THE BODY, NOT FROM THE TIMETABLE.

Order how to work out what somebody needs

Put these five steps into the order you would follow to estimate a person's daily energy requirement, ending with what the figure is for.

Establish the body: size, and how much of it is muscle rather than fat
Use that to find the energy used at complete rest
Add anything the body is currently paying for, such as growth, pregnancy or recovery
Apply a multiplier for how much the person moves over a day
Read off the total, and compare it with what is actually being taken in

Build the sentence that explains a difference

This is the sentence that turns two figures into an explanation. Assemble it.

The energy budget run

Five questions on the resting bill, the multiplier and the three claims. Three lives.

Complete the energy balance facts

The energy a body uses at complete rest simply to stay alive is its _____. A multiplier describing how much movement a person does over a day is their _____. The metric unit of energy, printed on labels alongside the more familiar one, is the _____. The unit usually printed largest on food labels in Britain is the _____.

basal metabolic rate physical activity level kilojoule kilocalorie energy balance dietary reference value macronutrient micronutrient

Three explanations to correct

Three student answers about energy requirements. In each case the mark is in the mechanism, not the verdict.

An answer explains why an older adult may need less energy than they did at thirty by saying they have simply become less active. What is incomplete about it?
A student writes that the specification requires certain percentages of energy to come from each macronutrient, and quotes them. What should they do instead?
An answer about a long-term energy shortfall discusses weight only, and does not mention protein at all. What has it missed?

Explain two different requirements

Two people of the same age have noticeably different daily energy requirements. Explain how that comes about, and what would happen to each of them if their intake fell well short of it for a long period.

Explain what sets the energy each body uses at complete rest, and why it differs between the two
Explain why activity is applied as a multiplier to that figure rather than added to it
Explain one thing other than body size that can raise the resting figure, and say why it is paid for out of that part
Explain what each of the three macronutrients is claiming the energy for, and which of them is primarily a building material
Explain what happens to protein when the budget falls short, and why repair suffers as a result
Avoid quoting any figure you are not certain of, and if you use national dietary guidance say that is what it is

Energy Balance and Macronutrients: Protein, Fat and Carbohydrate

Justify the choices, the way you are assessed

What you'll cover