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Health and Nutrition

M&S Health & Nutrition

Losing Weight

Losing Weight


Energy is needed for every body function - moving, breathing, growth and repair all need energy. We get our energy from the foods and it is measured in either kilo joules (kJ) or kilo calories (kcals).

The energy content of a food or drink depends on how many grams of carbohydrate, fat, protein and/or alcohol the food contains. Fat has almost twice the amount of energy per gram than carbohydrates or protein- and alcohol provides nearly as many calories as fat (so drink it in moderation).

Energy Balance

Energy balance is the difference between our energy intake (from the food we eat) and energy expenditure (from our body functions and physical activity).

If your energy intake equals your energy expenditure, you are in energy balance and your weight will be stable. When you eat more energy than your body needs, you're no longer in energy balance and your body stores the excess energy as fat in adipose tissue- so try not to consume more calories than you use!

If we continually consume more energy than we expend our body fat stores will increase. This will lead to weight gain and eventually to overweight and obesity. If we are overweight this is an indication that your energy balance has been "out of balance" for quite a while.

Energy Requirements

The average number of calories required each day for women is 2,000 calories and 2,500 calories for men, however this varies on an individual basis and depends on many factors including sex, height, weight and how active you are. The more active you are the more calories your body needs. Use our Diet Plan tool to find out how many calories your body needs each day.

Causes of Weight Gain and Obesity

It's all driven by energy balance but the causes are complex:

The Environment - We now live our lives in what can be described as an 'obesogenic' environment. Food today is available 24-7 and in addition we spend most of our day in front of computers, televisions, using lifts, escalators and driving - all of which affects our energy balance.

Genetics- There is some evidence to suggest that our genetics have a role to play in determining whether we are more likely to become obese, however it is our lifestyles and diet that really determines whether we become overweight or obese.

Why Worry About Being Overweight?

Obesity and being overweight are on the increase in the UK and the rest of the world. In Britain almost two thirds of adults and one third of children are overweight or obese. If current trends continue, this is set to rise to 9 in 10 adults and two thirds of children being overweight or obese by 2050 (Department of Health)

Obesity can be defined as a condition of abnormal or excessive fat accumulation to the extent that health may be impaired. If you are overweight or obese, you also have an increased risk of a number of illnesses- some of these include:

  • Some types of cancer
  • Heart disease
  • Type 2 diabetes
  • Gall stones
  • Osteoarthritis
  • High blood pressure
  • Raised cholesterol
  • Stroke
  • Gall bladder disease
  • Back pain
  • Depression - low self-esteem and social isolation
  • Breathlessness
  • Asthma
  • Sleep problems including sleep apnoea
  • Infertility and irregular periods
  • Polycystic ovarian syndrome (PCOS)

Changing your lifestyle by being more active (increasing your energy use) and by choosing a balance of the right foods (decreasing in your energy consumption) can all help you to become your healthy weight and enjoy your life to the full.

How to tell if you are overweight?

  1. Weigh yourself
    By weighing yourself on the scales every week, you'll see if you are gaining or losing weight. Click here to track your weight online. However this does not indicate whether you are overweight or obese and need to lose weight though
  2. Calculate your Body Mass Index (BMI)
    Your body mass index can provide an indication that you may need to lose weight.  BMI is calculated by the following formula (weight always in kg and height in m):

BMI = weight (kg) [divided by] height (m)2

For example, if you weight 85kg and your height is 1.73m, your BMI would be:
85/ 1.732  = 28.3

The following is a guide to whether you're under, over or a healthy weight:

  • If BMI less than 18.5 - underweight
  • If BMI 18.5-25 - healthy weight
  • If BMI more than 25 - overweight - important not to gain weight
  • If BMI more than 30 -40 obese - lose weight
  • If  BMI more than 40- morbidly obese

A strong relationship exists between BMI and associated risk from diseases such as heart disease and Type 2 diabetes. Having a BMI greater than 25 has been shown to increase the risk of these diseases.

However, if you have a lot of muscle you could have a BMI over 25 but still have a healthy body shape. So body shape is also important in determining if you need to lose weight.

Calculate your BMI using our BMI Calculator

3) Check Your Body Shape

The Ashwell® Shape Chart can help you determine whether your waist is the right size for your height. Carrying too much weight around your middle may increase your risk of developing heart disease and diabetes. Click here to check your body shape

Use our weight loss tools to calculate your BMI and check your body shape

Losing weight

So you have been advised that you may need to lose weight? Despite our genetic make-up and the obesogenic environment working against us, there are small changes you can make to your lifestyle to take control of your weight and tip the scales in your favour!

For weight loss, as a guide, women should aim to stick to 1500 calories and men around 2000 a day.  Or more generally eat around 500 calories less than you are at the moment! Use your diet plan to help you to find out how many calories you need to lose weight.

It is important to lose weight gradually, no more than 0.5kg-1 kg a week, In the same way as we put on weight - if we expend (or use up) more energy than we consume our body fat stores will decrease.
This can be done by :

  • Increasing the amount of energy expended by getting active - for ideas and tips on getting started see our get active section
  • Decreasing energy intake made through dietary changes - our Balanced For You and Count on us ranges have been specially developed to be calorie controlled.

The latest research shows weight loss will only be successful if you are truly ready to lose weight. We can provide you with information and support but nobody can take responsibility for your own weight- it's down to you.

Think about why you want to lose weight. Are you doing this for you? Are you doing this for your health or because you would feel better about your appearance if you were slimmer? Set yourself goals and make a list of all the reasons you would like to take more control over your weight and keep hold of it to motivate yourself - why not print it out and stick it on the fridge door to remind yourself!

Weight loss tips

1) Don't skip meals. Research has shown regular eating habits are important for weight control - so it is important that you plan to have three meals a day. Skipping meals, in particular breakfast will not help you to lose weight. Instead you will be more likely to snack on high-fat or high-sugar snacks later in the day.

2) If you tend to snack between meals then plan ahead and cut down at meal times, or save your dessert as a snack for later.

3) Follow the Balance of Good Health guidelines for achieving a healthy and well-balanced diet.

4) Choose low fat foods whenever possible, for example, skimmed or semi-skimmed milk, low fat spreads, tomato-based rather than creamy pasta sauces, lemon juice or balsamic vinegar salad dressings instead of oil or mayonnaise.

5) If you are not losing weight, choose smaller portions or try to up your activity levels