Frequently Asked Questions

Are crash diets really that bad?

Yes! Not only are they bad for your health but they don’t work.

A balanced diet means eating food from all the food groups. Cutting out foods means cutting out nutrients and this can have serious short- and long-term effects on your health. If you dramatically restrict your calorie intake you will lose weight – but as soon as you start eating normally again you’ll put all the weight back on, and probably more. This is because your body’s metabolism slows down to conserve energy once it realises there’s less food available. When you start eating again your slow metabolism won’t be able to process the energy, which will be stored as fat. This stored fat will also reassure the body that it’s prepared for future crash diets.

The only way to lose weight safely and keep it off is to eat a healthy, balanced diet and do more exercise. The exercise will boost your metabolism and burn fat even between gym sessions.

Are vitamin supplements safe?

If your diet is varied and balanced there is no reason to think that you need supplements. It’s also not known whether vitamins and minerals in supplement form can provide the same benefits as food, which contains all sorts of nutrients we can’t recreate in pill form.

There are some situations where supplementation is recommended:

• Women who are planning to get pregnant, or have just become pregnant, should take a daily supplement of 400mcg (micrograms) of folic acid to help prevent their baby from developing a neural tube defect such as spina bifida.

• People who always cover their skin when outside and those who rarely get outdoors and have a limited exposure to sunlight may lack vitamin D, which could be taken in supplement form (10mcg a day).

• Vegans who never eat meat or dairy products may need to take vitamin B12 in tablet form.

It is possible to take too much of a particular vitamin. Fat-soluble vitamins that will be stored in the liver, like vitamin A, can reach toxic levels and cause liver damage. Pregnant women should avoid supplements containing vitamin A, including fish liver oil supplements, because too much vitamin A could harm their unborn baby. Of the water-soluble vitamins, taking large amounts of vitamin C can cause diarrhoea (2000mg a day) in some people.

How much alcohol is it safe to drink?

The Department of Health says that men should not regularly drink more than 3 - 4 units of alcohol per day, and women should not regularly drink more than 2 - 3 units of alcohol per day.

It also advises pregnant women or women who are trying to conceive, to avoid drinking alcohol. If they do choose to drink, to minimise the risk to the baby, they should not drink more than 1 - 2 units of alcohol once or twice a week and should not get drunk.

Alcoholic drinks vary in strength and in serving sizes. For example, ordinary strength lager like Fosters has 2 units in a pint, but a pint of strong lager like Stella contains 3 units. Wine served in pubs is stronger than it used to be and served in bigger glasses. Asda brand alcohol tells you the number of units on the label.

How much exercise should I be doing?

Government guidelines say that adults should be moderately active for at least half an hour a day, five days a week. Children should be moderately active for at least an hour every day. ‘Moderately intensive’ physical activity will leave you slightly breathless.

Some research has suggested that moderate intensity activity is not enough to promote health and say that you should combine it with more vigorous activity, including weight training, for real health benefits. It’s difficult to give a one-size-fits-all answer but 30 minutes a day is a good place to start if you currently do very little exercise.

How do I know if I’m a healthy weight for my height?

Body Mass Index, or BMI, is an indication of whether you’re a healthy weight for your height.

You can get your BMI measured at an Asda pharmacy, or follow these steps to calculate your BMI yourself:

1. Work out your height in metres and multiply the figure by itself

2. Measure your weight in kilograms

3. Divide the weight by the answer to Q1

For example:

Your height is 1.68m (5ft 6in)

Your weight is 65kg (10st 4lb)

1. 1.68 x 1.68 = 2.82

2. 65kg

3. 65 divided by 2.82 = 23 BMI

Underweight: less than 18.4

Ideal weight: between 18.5 and 24.9

Over the ideal weight: between 25 and 29.9

Obese: between 30 and 39.9

Very obese: over 40

The BMI is often criticised because it is not accurate for everyone.

It should not be used to measure children, or women who are pregnant or breastfeeding.

It is also not suitable to measure people who are frail, those with a long-term health condition or older people.