Treatment: diet

Coping with diabetes

Diabetes can be tackled in three main ways.

Diet

A diabetic diet actually means following a healthy eating plan rather than a difficult or restrictive programme. This applies to everyone with diabetes, regardless of which type they have, and may be enough by itself to control type 2 in some people.
However, if you have type 1 diabetes, you will need to learn about balancing your intake of food with your insulin injections in order to achieve the best possible control of your blood glucose levels.

Tablets

These are used to control type 2 and there are different types. For more about this kind of treatment, see page 44.

Insulin

Everyone with type 1 diabetes will have to take insulin by injection, but only a minority of those with type 2 diabetes will be treated this way. More about insulin on page 49.

Your healthy eating plan

The sort of diet that you should follow when you have diabetes definitely does not mean a future of self-denial on the food front. What it does mean is eating more of the foods that are good for you, and cutting right down on those that are not so good. Actually it’s the kind of eating that experts recommend for everyone, whether or not they have diabetes.

The difference that it can make to your overall health and well-being is even more worthwhile when you do have diabetes, however, because without it your medication will not be nearly as effective.

A balanced diet

It is important to have a good mix of foods so eat a wide range of different nutrients; also try to cut back on those that are high in fat and sugar. Once you get used to the basics, however, it’s mostly quite simple, as you will see from our guidelines on the next few pages.

Eat regular meals

You should find it easier to keep your blood glucose levels under control if you eat at regular mealtimes. This may also be beneficial to aid weight loss. Aim to have three meals per day or eat approximately every four hours, that is breakfast, lunch and evening meal (see ‘Healthy eating menu’, page 20).
Some people may need to have a small snack, for example cereal or toast or snacks between meals, but this should be discussed with your diabetes team.

Healthy eating menu

A well-balanced diet helps control your diabetes and ensures that your medication works effectively. This chart will give you some ideas for the foods that you should include in your meals.

Breakfast

• Skimmed or semi-skimmed milk
• Artificial sweetener instead of sugar
• High-fibre cereal, e.g. porridge, Branflakes, Weetabix, Shredded Wheat
• Wholemeal or wholegrain bread
• Poly- or monounsaturated or low-fat spreads
• Low-sugar jam or marmalade
• Fruit

Main meal

• Include some starchy food – bread, potatoes, pasta, rice or chapatti, for example
• At least two portions of vegetables, and try to include peas and beans as often as possible
• Small portions of lean meat or fish. Cut off fat, and avoid frying
• Fresh or tinned fruit (in natural, unsweetened juices), plus unsweetened/sugar-free jelly or custard

Snack meals

• Bread, pasta, chapatti or jacket potatoes – go for low-fat fillings such as lean meat, baked beans, low-fat cheese or tinned fish (not in oil)
• Fresh or tinned fruit in natural juice

Eating between meals

Snacks/Supper

• Avoid eating too many of these if you’re trying to lose weight, and stick to fruit instead
• Sandwiches or toast with low-fat fillings
• Bowl of cereal or porridge
• Low-fat crisps
• Plain biscuits
• Toasted crumpets and muffins

The different food types

Carbohydrates

There are different types of carbohydrate, which are broken down by the body at different rates to produce glucose (sugar). In simple terms a carbohydrate can raise blood glucose levels dramatically (quick release), moderately or a little bit (slow release). Foods that have only a slow release have a small effect on blood glucose, whereas those with a quick release cause a rapid and massive rise in blood glucose level.
Try to have some slower-release carbohydrates at each meal, because they are a good source of energy and help to fill you up. They can also keep your blood glucose levels stable. Slow-release carbohydrates can be found in bread, pasta, rice, chapattis, breakfast cereals, potatoes, and so on.
Sugary foods are digested quickly and are rapidly absorbed into your bloodstream and increase your blood glucose levels, for example sugar, sweet fizzy drinks, sweets and chocolate, cakes and biscuits. There is no harm in having these foods occasionally but try to take sugar-free or low-sugar alternatives. Use diet or no-added-sugar drinks, have plain biscuits and cakes occasionally, and limit portion size.
The best time to have something sweet is with or after a main meal because the sugar is more slowly absorbed with other food types.
Modify your favourite recipes to use less sugar, for example cakes. Sugary foods are high in calories so it is best to limit these foods if you are concerned about your weight.

Carbohydrate counting

As carbohydrate is the main immediate source of glucose from the diet, there is a school of thought that suggests that people with diabetes should try to calculate how much there is in each meal and adjust the insulin dose accordingly. Thus, a meal with more carbohydrate would need a larger dose of insulin and vice versa.
This system is called carbohydrate counting and is particularly useful for patients using multiple insulin injections (see page 53) or an infusion pump (page 61).
The convention is to have 1 unit of insulin for every 7 to 20 grams of carbohydrate, depending on age and body size.
This method is similar to the old system of carbohydrate exchanges but does not involve a daily limit on the amount in the diet. It is simply a method
of trying to match insulin dose to meal size.
The table opposite shows examples of the amounts of some common foods that are equivalent to 15 grams of carbohydrate. This system has been tested in a large research study sponsored by Diabetes UK – the Dose Adjustment For Normal Eating (DAFNE) Project.

Portions of foods equivalent to 15 grams of carbohydrate

Bread and cereals

One slice wholemeal

Six dry crackers

One muffin/hot dog roll/hamburger bun

25 grams (1 oz) unsweetened cereal

Vegetables

50 g (2 oz) cooked Brussels sprouts, carrots, leeks, cabbage, cauliflower
Mashed potato – 100 g
Chips – 50 g (equivalent to 16–25)
Half a medium-sized baked potato
Cooked rice 50 g (2 oz)
Pasta – 70 g (2.5 oz)
Double quantity for raw portions

Fruit

One apple (150 g)

One large orange

One small banana

Half a grapefruit

Two kiwi fruit

Drink

Fruit juice 150 ml (3 oz)
Beer 1 pint
Milk half a pint (any type)

By teaching type 1 patients how to adjust insulin to the carbohydrate content of an unrestricted diet, blood glucose levels were much better controlled at the end of one year than in a group of patients in whom this training had been delayed. It is planned to extend this programme across the UK.
For type 2 patients, a programme called DESMOND (Diabetes Education and Self-Management for Ongoing and Newly Diagnosed) has shown promising results. More information can be obtained from Diabetes UK (see page 147).

Fat

A diet rich in fat can lead to weight gain, raise blood cholesterol and contribute to heart disease. It can also make the body less responsive to insulin. There are two main types: saturated and unsaturated fat.

Saturated (animal) fat

This is found in butter, lard, fatty meats, pastries, and so on. This type of fat can increase your cholesterol level (see ‘If it gets complicated’, page 107). It is therefore important to reduce the intake of these types of foods. Instead try to increase the amount of fruit and vegetables, pulses such as lentils and beans, oily fish and oats.

Unsaturated fats

These are slightly better for you than saturated fats
and come in two forms:
1 Polyunsaturated fats are found in sunflower oil, pure vegetable oil, corn oil and sunflower margarines. They have little effect on cholesterol levels.

2 Monounsaturated fats are found in olive oil and olive oil-based margarines, rapeseed and safflower oil, and most nuts. This type of fat is thought to be most beneficial because it may reduce blood levels of your ‘bad’ cholesterol (low-density lipoprotein or LDL for short) and increase your ‘good’ cholesterol (high-density lipoprotein or HDL for short). This type of fat should be used instead of saturated or polyunsaturated, whenever possible.
Trans-fatty acids are formed when fats undergo a chemical process to make them hard, termed ‘hydrogenation’. Trans-fat raises LDL-cholesterol and lowers HDL-cholesterol levels, and so can increase the risk of heart disease. It is therefore important to limit the amount of foods containing them.

They are found mainly in hard margarine, crackers, biscuits, cakes, fried foods, pastries, baked goods and other processed foods made with or fried in partially
hydrogenated oils. They may also be found in small amounts in various meat and dairy products.
Remember that all fats are high in calories and may lead to weight gain if taken in excess.

Oily fish

Oily fish such as mackerel, herring, kippers, salmon, trout, sardines and pilchards contain beneficial oils known as omega-3 (or .-3) oils. Research has shown that these oils help to reduce the stickiness of the blood and lower cholesterol levels.
They may also protect against heart disease by helping the heart beat more regularly and protecting blood vessels. They are also thought to be beneficial in reducing inflammation and can help reduce arthritis symptoms.
Despite the recent research suggesting only a modest benefit, dietary experts recommend trying to have oily fish once or twice a week. Buy them fresh,
tinned in brine (tinned tuna does not count because the omega-3 oil is destroyed during processing) or in tomato sauce, but avoid fish in any type of oil.
There are omega-3 supplement capsules available, which contain beneficial fish oils. However, there is not enough evidence to support their use in people with
diabetes at the moment and they are expensive. It is best to obtain oils from fish themselves rather than from supplements.
If you do not like fish, then try the following instead: green leafy vegetables, nuts and seeds or omega 3-enriched foods, for example Columbus eggs.

Fibre

Fibre (also called roughage) can be either soluble (dissolves in water and slows absorption of food) or insoluble (cannot be digested and helps to prevent constipation). Insoluble fibre is also useful when you are trying to lose weight because it makes you feel full up.

Advice to help you get the most out of your food

Handy tips

• Have fruit or vegetables with every meal and have as snacks between meals
• Add extra vegetables to casseroles, curries, soups
• Add fruit to breakfast cereals

Cooking tips

• Cook vegetables for a short time in a little water to avoid destroying the vitamins and minerals
• Try microwaving, steaming or stir frying vegetables in a small amount of oil

Increasing the fibre content of your diet doesn’t mean having brown rice and bran with everything, but you should aim to consume around 30 grams of fibre a day. It is essential to keep your intestine working well, and some food types such as soluble fibre can help with both good blood glucose control and keeping your blood cholesterol levels down.

Soluble fibre foods

Foods such as baked beans, mushy peas, lentil soup and dhal, plus oat-based dishes such as porridge and other cereals and oat cakes, are high in soluble fibre.

Insoluble fibre foods

Food such as high-fibre cereals, wholemeal or granary bread, unpeeled vegetables and fruit, plus wholemeal versions of pasta, flour and rice, have mainly insoluble fibre.

The importance of water

If you increase the fibre content of your diet it is important to increase fluid. Aim to drink eight to ten glasses of fluid per day – for example, squash with no added sugar, water, tea – because this helps to soften your motions and prevents constipation.

Fruit and vegetables

These are important, because they are low in fat and calories and provide plenty of vitamins, minerals and fibre. All fruit contains a small amount of natural sugar. It is therefore important that you spread your fruit intake over the day in order to minimise the amount of sugar that you take in at any one time.
It is recommended that you aim for five portions per day. This may help to protect against heart disease and decrease cholesterol levels. Fresh, frozen and tinned fruit in natural juice are all suitable. Potatoes are not usually counted as a vegetable portion but they are of course an important source of carbohydrate. If you are eating a well-balanced diet, you really should not need to take any extra vitamin or mineral supplements.

Protein

Protein is an important part of your diet because it is required for repair of tissue and muscle and is needed to fuel normal growth in children. You need only a relatively small amount – look up the value in the table on page 34.
Good sources of protein include eggs, fish, meat and dairy produce. Some of these foods can be high in fat, so it is important to use low-fat or diet versions when you are able to.

Salt

Too much salt can increase your blood pressure (known as hypertension). You should not eat more than six grams (one heaped teaspoon) of salt per day. If you suffer from hypertension then you should eat less than three grams of salt per day (half a teaspoon). To calculate how much salt is in a product, multiply the sodium level (often found on the label of tins or packets) by 2.5.
Try to taste your food first. You may not need to add salt; instead use herbs, spices, lemon juice, pepper, garlic, and so on. Do not add salt in cooking or at the table. There is a lot of salt hidden in processed food such as tinned or ready-made meals, cured meats, pizzas, and so on, so try to eat less of these. Cut down on salty snacks such as crisps and salted/toasted nuts.

Special diets

High-protein/low-carbohydrate diets are marketed by some as being particularly good for individuals who wish to lose weight. There is some scientific basis for these claims, but, if you are on any form of tablet or insulin treatment, you should get expert advice from your diabetes team before starting such a diet. A dramatic reduction in carbohydrate intake might result in hypoglycaemia (see page 76).
High-protein diets may have a long-term damaging effect on the kidneys, particularly in patients with proteinuria and early kidney failure (see page 113). Until the long-term safety of these diets is confirmed a balanced intake of a mixture of proteins, carbohydrates and fats, as outlined above, is still the safest choice.

Diabetic foods

It is better to avoid those foods such as diabetic chocolate, sweets and jam because they offer no benefits to people with diabetes. They can cause diarrhoea if eaten in large quantities because they contain a sweetener called sorbitol, which is not absorbed. They can also be high in fat and are expensive.

Controlling your weight

Type 2 diabetes is often associated with being overweight and obesity can make it more difficult to control blood glucose. If you are overweight (see chart opposite) then losing some weight will be beneficial to your health. Even losing just 10 per cent of your body weight can make huge improvements to your health by improving your diabetes control, blood pressure and cholesterol levels.
Remember that you will lose weight only if you eat less food than your body needs to fuel its daily activities. You may find it easier to introduce changes gradually rather than all at once. Your family may like to be involved and change their diet in order to eat more healthily. Our healthy eating menu (see page 20) shows how you might do this; substitute the foods listed for your usual ones.

Try these tips to lose weight

• Cut down on fried and fatty foods (see page 26)
• Eat smaller portions
• Cut out snacks such as crisps and biscuits; try fruit instead
• Eat regular meals
• Take more exercise

If you would like to discuss any of these points or would like more information, ask your doctor to refer you to see a dietitian.

Glycaemic index (GI)

The glycaemic index (GI) can be used as a guide to measure how quickly foods that contain carbohydrate raise blood glucose levels. The index has been calculated by looking at the rise in blood glucose levels after ingesting 50 grams of carbohydrate contained in individual carbohydrate foods.

High and low GI foods

Foods are given a value of 0 to 100, with glucose being
100. Foods with a GI greater than 70 are classed as high GI foods, so they increase blood glucose quickly; those with a GI of 58 to 69 are classed as medium GI foods and have a moderate effect on blood glucose; those with a GI less than 55 are classed as low GI foods because they have a slow or only minor impact on blood glucose levels.
It seems sensible to follow a low GI diet, but you need to be aware of the following points:
• Foods with a low GI value tend to be high in fibre. They are digested slowly and so lower the GI response; they will have less effect on blood glucose after a meal.
• Foods with a low GI value tend to fill you up for longer, which can be beneficial for weight loss because you may be inclined to eat less.
• There is some evidence to suggest that glycaemic control improves in people who eat foods with a low GI value.
• Low GI foods have been found to increase HDL-cholesterol and lower the total cholesterol and triglyceride levels – a good thing!
• The addition of seeds or grains tends to lower the GI, for example granary bread has a lower GI than wholemeal bread.
• The GI takes into account only single foods. If you eat more than one type of carbohydrate at a time then the GI changes. If high and low GI foods are eaten together, the GI value of the meal will be halfway between the two individual values.
• Cooking and preparation of food can alter the GI value, for example mashed potato (high) or chips (medium). Cooking breaks down the chemical bonds in complex carbohydrates, which makes them easier to absorb and will therefore increase the GI. This does not happen with pulses, however, which have a GI that remains low after cooking. The bonds are also broken when food is chewed, which can therefore raise the GI.
• Highly processed convenience foods tend to have a high GI, for example pastries.
• Ripeness can affect the GI. A ripe banana will have a higher GI than an unripe one.

Some low GI foods are so slowly absorbed, for example pulses/nuts, that insulin may be absorbed more rapidly than digested food. A diet high in these types of foods may predispose to low blood glucose levels (see ‘All about hypoglycaemia’, page 76).
Fat and protein slow down the absorption of carbohydrate and therefore lower the GI value, for example chips and crisps have a lower GI than potatoes because of their fat content. However, eating low GI foods that are high in fat can lead to weight gain.
As a result of these concerns there may be problems in following a GI diet to the letter, but it is useful to be aware of the GI of foods that you eat
regularly. It is sensible to have a low GI food at each mealtime.
Overall it is important to follow a balanced diet, rich in fibre, fruit and vegetables, low in fat and salt, so use any knowledge of GI as part of an overall dietary strategy.

Glycaemic index of different foods

High glycaemic index

• Glucose
• Instant mashed potato
• Mashed potato
• Jacket potato
• Cornflakes
• Jelly sweets
• White bread

Medium glycaemic index

• Basmati rice
• Honey
• Banana (ripe)
• Boiled potatoes
• Grain bread, e.g. granary

Low glycaemic index

• Banana (unripe)
• Apple
• Lentils
• Nuts

Alcohol

Having diabetes doesn’t mean turning teetotal unless you prefer to, but you do have to follow a few commonsense rules, particularly if you are on tablets or insulin. Remember that alcohol can cause hypoglycaemia in certain circumstances (low blood glucose, see page 76).
• Limit yourself to the correct number of ‘units’ in any one day as shown on page 42. One unit of alcohol means a single measure of spirits, half a pint of beer or a small glass of wine.
• Avoid ‘diabetic’ or Pils-type beers or lagers because, although they have less sugar, they are high in alcohol and more likely to cause a low blood glucose.
• Drink alcohol with or just after a meal and make sure that you have some slow-release carbohydrate with it. You will need a snack before you go to bed in order to help prevent your blood glucose levels from dropping during the night.
• You may find that your face flushes red if you mix alcohol with some kinds of diabetes tablet treatment.
• Remember to allow for the calorie content of alcoholic drinks and mixers, which should be diet/slimline versions.

Current government recommendations for alcohol intake are as follows:
• 1–2 units per day, 14 units per week for women
• 2–3 units per day, 21 units per week for men
• Always have some alcohol-free days during the week.

KEY POINTS

• Eat regularly

• Include some starchy food (carbohydrate) with each meal, choosing high-fibre versions where possible

• Reduce your fat intake and remember to watch the type of fat

• Limit your intake of sugars and sugary foods

• Aim to keep to your ideal body weight and exercise regularly when possible

• Use salt sparingly

• Do not drink too much alcohol