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The last section looked at the energy equation and the different factors that can affect it. Now the time has come to apply those principles to individual circumstances.

must know

Calories

One calorie (4.2 joules) is the amount of energy required to raise the temperature of 1 gram of water by 1 degree Centigrade. Nutritionists measure the calorie values of foods by burning them in a calorimeter to see how much heat they give off. The major food groups differ in ‘energy density’ –the number of calories they contain per gram:

Fats have 9 calories per gram.

Alcohol has 7 calories per gram.

Carbohydrates have 4 calories per gram.

Proteins have 4 calories per gram.

Altering the energy balance

The next few pages set out how far to reduce your calorie intake and increase your calorie output in order to create your own personalized slimming plan which will guarantee safe and steady weight loss.

As the previous chapter showed, the science behind weight loss and weight gain is all about the energy equation: consuming more energy, in the form of food, than is expended in activity results in weight gain. To lose weight, it is essential to create an ‘energy deficit’ so that more energy is expended in activity than is taken into the body as food.

Units of energy

The units of energy used to measure this process are kilojoules or calories – the word that can be very off-putting for people who have followed the kind of diet that requires the counting and measuring of every single mouthful they consume. Unfortunately, it is impossible to ignore calories when trying to lose weight. It is true that there are plenty of diets that promise you ‘need never count another calorie’. This is generally because they either give calories another name, such as ‘units’, or because they ensure that calorie intake is controlled automatically by limiting the kinds of foods that can be eaten.

Calculating your energy deficit

The aim of this section is to show you how to calculate a personalized energy deficit by working out:

Your current energy expenditure.

Your current energy consumption.

Your daily energy requirements needed to lose weight steadily.

Inevitably, this means talking about calories. However, it is possible to lose weight easily by being calorie-conscious and without having to become a calorie slave

must know

Calorie guides

Buy a calorie counter book for an at-a-glance guide to thousands of everyday foods. These are available at most newsagents and bookshops. Don’t guesstimate!

Bulky, watery foods like salad vegetables make good low-calorie fillers in a slimming diet.

must know

Diet or exercise?

When thinking about losing weight, men and women tend to have different approaches: women say it’s ‘time to start the diet’ and men say it’s ‘time to hit the gym’. It is perfectly possible to create an energy deficit by changing your diet alone, or just by doing a lot more exercise (although the exercise-only route is slower). The perfect combination for health and weight loss is to do both: to make some small changes to your diet, and to become a bit more active as often as possible.

Where does it all go?

The body uses the food we eat in three main ways: for growth; to replace damaged or worn-out tissues; and to fulfil all the body’s daily functions, which can range from breathing to ballroom dancing. The amount of energy needed from food to keep the body going, without gaining or losing weight, is called the basal metabolic rate (BMR). Any energy (calories) which is taken in over and above the requirements of the BMR is stored – and, as the last chapter showed, this is one thing at which the body is very efficient.

Once food has been digested, any surplus energy is stored either as glycogen – a short-term energy source, which is stored in the liver and the muscles – or as fat, which is stored in ‘fat depots’ under the skin, around the kidneys and in the abdomen. There is a limit as to how much glycogen can be stored before it is released back into the bloodstream to be used, but there is no limit to the amount of fat that can be stored. Fat cells get bigger, multiply and form adipose tissue which can eventually present a threat to our health.

It takes about 3,500 calories surplus to the requirements of the BMR to create 1lb (454 g) of stored energy (otherwise known as fat). So an individual whose BMR is 2,500 calories per day, and who eats 3,000 calories’ worth of food per day without changing his or her activity level in any way, could expect to put on a pound a week (7x500 = 3,500 calories). In practice, our body weight fluctuates from day to day and even at different times of the day, which is why it is best to weigh yourself only once a week at the same time –jumping on the scales more often can be misleading. However, overtime, a steady over-supply of calories without an increase in activity to compensate will surely result in a weight gain.

Healthy home-grown vegetables: fantastic for taste, freshness and providing valuable nutrients.

And in the same way, creating an energy deficit, so that more energy is expended than the BMR requires, will equally surely result, overtime, in weight loss. So, again, someone whose BMR is 2,500 calories and who eats 2,000 calories’ worth of food each day could expect to lose a pound a week.

Find your balance

There are four steps to working out your basal metabolic rate (BMR):

1 Assessing the resting metabolic expenditure (RME).

2 Making an allowance for activity.

3 Adding in 10 per cent for the energy used in digesting food.

4 Totalling it all up.

As you will see from the instructions and the example given below, this is much easier than it sounds.

Step 1

Use the table to read off your RME. The differences in the table are accounted for by gender and age: generally, men need more calories than women to maintain their weight because they have a higher percentage of muscle tissue, which burns fuel more efficiently than fat. Age is a factor, too, because the amount of energy the body needs for maintenance peaks at the age of about 25 and declines gradually after that, at a rate of about two per cent per decade.

Your RME

Age – Men	RME equation
18–30	15.3 x weight (kg) + 679
30 –60	11.6 x weight (kg) + 879
60 and above	13.5 x weight (kg) + 487

Age – Women	RME equation
18–30	14.7 x weight (kg) + 496
30 –60	8.7 x weight (kg) + 829
60 and above	10.5 x weight (kg) + 596

Step 2

Factor in your activity level, based on what you normally spend most of the day doing. The guidelines and calculation are as in the table opposite (top).

Multiply your RME from Step 1 by the activity factor to find the number of calories needed for activity each day.

Your activity level

Usual daily activities	Activity Level	Activity Factor
Desk job or light housework; driving; reading; watching TV	Very light	0.2
Childcare; light exercise, e.g. walks; moderate housework; light manual work, e.g. mechanic, waiter	Light	0.3
Moving about all day; spring-cleaning; heavy gardening; active sports	Moderate	0.4
Heavy manual work, e.g. building, digging high-energy sport, e.g. football	Heavy	0.5

Step 3

Add together your RME figure and your ‘activity calories’ figure and divide by 10 to find the calories needed for digestion.

Step 4

Add together your RME figure, ‘activity calories’ figure and ‘digestion calories’ figure in order to find your BMR (basal metabolic rate) – the total number of calories that are needed each day to maintain your weight.

To lose weight steadily, the best combination is to reduce your calorie intake and to increase your calorie expenditure by making changes to your daily diet and activity levels.

must know

Working out BMR

Jane is a 30-year-old mother of two with a part-time office job. She weighs 76 kg (12 stone).

In step 1, Jane works out her RME to be: 8.7 x 76 + 829 = 1,490 calories.

In step 2, she estimates her activity level as ‘light’ and her activity factor as 0.3. So the calories she needs for activity are: 1,490 x 0.3 = 447

In step 3, Jane adds her RME and activity calories together and divides by 10 to find the calories she needs for digestion: 1,490 + 447 = 1,937 10 = 193

In step 4, she adds the three totals together to find her BMR (total daily calorie needs): 1,490 + 447 + 193 = 2,130 calories.

Keeping a food diary

Having worked out how many calories you need to maintain your current weight, the next step is to work out how many calories you are taking in as food. Nutritionists recommend that the best way to do this is to keep a food diary. To get a full picture of calorie intake it is important to keep the diary for at least a week, or longer if you feel it would be helpful. Keeping a food diary sounds easy but, in practice, researchers have found that people who are asked to record their food intake almost always under-report what they actually eat. However, to identify patterns of where calories are coming from and where easy savings can be made, it is important to be as detailed and honest as possible – after all, no one else will see the diary. It is also important to eat and drink exactly as usual and not to change your normal routine in any way, as you need to keep track of all the occasions during the week when you might have an opportunity to save calories.

must know

Calorie savings

Look over your food diary to identify the areas where it would be easy for you to make calorie savings.

Sample food diary for a single day

Breakfast

Med egg, 2 rashers back bacon, 1 tbsp vegetable oil, 2 slices white toast, 2 tsp butter, 200 ml glass orange juice, 2 cups tea, whole milk, 2 sugars

Lunch

100 g chicken, 15 cm baguette with 1 tbsp mayo, 25 g packet plain crisps, apple, 2 cups tea, whole milk, 2 sugars

Dinner

225 g grilled rump steak, 225 g jacket potato, 1 tbsp butter, 2 tbsp poached mushrooms, 1 grilled tomato, medium bowl strawberries, 2 tbsp double cream

Snacks/drinks

2 cups coffee, whole milk and 2 sugars; 2 chocolate digestives; 2 x 175 ml glasses red wine; 1 glass water

Total calories per day: 3,048

At this pre-weight loss stage your aim is just to observe everything you eat and drink over the diary period. You are not trying to lose weight – not yet anyway. The example shows the level of detail that is required.

Food diary rules

Write down everything you eat and drink, as you are eating it.

Always be specific – include cooking methods, brand names, quantities (estimate as closely as you can) and varieties, e.g. ‘diet drink’ or ‘full-fat yogurt’.

Include ‘hidden’ ingredients such as butter in sandwiches or sugar on cereal.

Identifying calorie savings

After a few days of diary keeping it may well be that eating patterns can be seen more clearly, so that it is possible to see ways of reducing your calorie intake by swapping to lower-calorie, lower-fat foods or by reducing portion sizes. For example, from the diary it can be seen that the day’s intake is high in sugar and in full-fat products, such as butter, milk and oil. The table below shows just how many calories could be saved by swapping to different varieties:

Swap this..	For this. . .	Calorie saving
12 tsp white sugar	12 tsp sweetener	192
300 ml whole milk	300 ml skimmed milk	90
2 tbsp double cream	2 tbsp light single cream	96
1 tbsp vegetable oil	10 sprays one-cal oil spray	125
2 X 175 ml red wine	1 X175 ml red wine	120

Making the swaps shown above would save 623 calories in a single day –without having to make any noticeable changes to the diet. Some people will find that there are easy, daily calorie-savings they can make in their diet, whereas others may identify regular but not daily occasions –such as a weekly takeaway or a night out –where big calorie-savings can be made at a stroke. This is why it is important to keep the food diary for as long as it takes to establish a pattern.

must know

Average intake

At the end of the diary period, the average daily calorie intake can be worked out by adding up the daily totals and dividing by the number of days. To do this, it is worth investing in a comprehensive calorie-counting guide which has thousands of food products, including branded ones.

How quickly should you lose?

Now that you know how many calories you need to maintain your weight, and how many you are currently eating each day, you can decide how much of an energy deficit you will need to set up to lose weight steadily and safely. Cutting back on food drastically– such as by sticking to a rigid 1,000 calories a day diet when your BMR is 3,000 calories – would undoubtedly lead to rapid weight loss. But it is very unlikely that you would be able to sustain it in the long term, leading to a dispiriting ‘failure’ and, probably, an equally rapid weight gain once you started eating normally again.

Gradual weight loss is best

Health professionals recommend that a safe and steady weight loss is about 1–2 lb (0.45–0.9 kg) a week. Slimming at this rate ensures that you will be losing fat rather than lean tissue, such as muscle, and it should be fairly easy to achieve without drastic calorie-cutting measures, so that you can stick with your plan without it feeling like a ‘diet’. And, as a bonus, research shows that people who lose weight slowly are more likely to keep it off in the long run.

As it takes an energy deficit of around 3,500 calories to lose 1lb of fat, a daily saving of about 500 calories should be enough to lose 1 lb a week (7 x 500). Saving 1,000 calories a day (say, from 3,000 to 2,000) could result in a 2lb weekly loss, but this depends on current intake: women should not try to lose weight on less than around 1,500 calories a day, while for men the minimum is around 1,900 calories a day.

In the first few weeks of a weight loss plan it is possible to lose more than 1lb or 2lb a week. This is because glycogen (the short-term store of surplus energy) is stored in three times its weight of water, which accounts for a lot of the initial weight loss. This can be a very motivating start to a weight-loss campaign and it may continue for longer than a week or two, especially if you have a lot of weight to lose.

must know

Working out calorie needs

For a rough guide to your daily calorie needs, multiply your weight in pounds by 15 if you are moderately active: or 13 if you have a sedentary lifestyle. Using Jane as an example, this method would estimate her total calorie needs at 2,173 compared to 2,130 for the four-step calculation.

There is no need for any drastic calorie cutting – or boring meals – when losing weight; healthy food can be filling and delicious.

must know

Calories from alcohol

These are not stored in the body but are used immediately as energy. That sounds like good news but it’s not; this is because instead the body stores calories from other sources such as fat, which tend to accumulate in fat deposits in the abdomen, and may account for the observation that many heavy drinkers are ‘apple-shaped’.

Weight loss, balance and health

This chapter has looked at ‘calories in and calories out’, a concept which is essential to understand in order to create an energy deficit. However, it is not enough on its own to help the slimmer because it does not address the other key question: what you should eat in order to ensure that a weight loss plan is also healthy, balanced and enjoyable for you to follow.

After all, if your only aim was to lose weight by creating an energy deficit, then the diet could consist of anything at all, as long as it saved calories. However, when you are devising an effective and personalized slimming plan, it is vital to ensure that your daily diet is healthy and balanced; that hunger is kept at bay; and that enough favourite foods are included so that the plan feels comfortable and enjoyable and you don’t feel that you are missing out on meals. All of these aspects are covered in the next section.

Adding lemon to a gin and tonic doesn’t make it healthy! Alcoholic drinks provide ‘empty calories’ with little nutritional value.

Energy deficit

By calculating your BMR and your calorie intake you will build up a picture of whether your current energy balance is likely to help you maintain your weight or whether you are consistently taking in too many calories for your needs.

Adjusting both your food intake and your activity level will help to shift the balance so that you begin to lose weight; it will be important to keep a food diary for the first few weeks of your weight loss plan so that you can keep track of all the meals, snacks and drinks that you consume.

Once you have started this process, have done all the calculations and are sure that you are in energy deficit but you are not losing weight, then the most likely explanation is that somewhere something has been missed; it may be that daily activity has been over-estimated, or calorie intake has been under-estimated. Another week’s food diary and another calculation of the ‘activity factor’ could reveal what has been happening.