How To: Time Insulin Injections for Simple Insulin Regimes

This section is for everyone.

If you are on a fixed dose insulin regime for any reason about the only thing you can manipulate to control blood sugar control is what you eat and the timing of your meals in relation to this.

These fixed insulin regimes are less common in the US but are very popular in the UK especially type 2s and also for type ones who are just starting on injections. Carb counting is not usually taught outwith special education courses such as DAFNE in the UK.

This educational course has given you lots of information that you can use to improve your diabetes control. If you have not yet got to grips with carb counting and the other advanced insulin techniques you may like to have some simple techniques that will improve your control meanwhile.

If you expect a meal to take longer to digest than is usual for sugars and starches eg it is high in protein, fat and low glycaemic carbohydrates (eg lasagne, pizza, lamb curry) you can:

  • Bolus 15 – 30minutes after you start eating for rapid acting analogues.(RAAs)
  • Split the bolus into two or three parts and give at 6-90 minute intervals. (RAAs)
  • Take regular insulin with the meal instead of a RAA.
  • Extend the bolus delivery time to over 2.5 hours if you are on a pump.

For people who are on or prefer to use a single injection of a RAAs:

  • For foods that are high GI foods – bolus before eating. eg a jam sandwich.
  • For moderate GI foods – bolus while eating. eg fish and chips.
  • For low GI foods- bolus after eating.


Your pre-meal blood sugar will also affect the optimal time you give your food boluses:

BS above target range:

High GI 30 – 45  minutes before a meal.

Medium GI 15 – 30 minutes before the meal.

Low GI 0-5 mins before the meal.

BS in target range:

High GI 15-30 mins before the meal.

Medium GI 0-5 mins before the meal.

Low GI 10-15 mins after you start the meal.

BS below your target range:

High GI 0-5 mins before the meal.

Medium  GI 10-15 mins after you start the meal.

Low GI 30-45 minutes after you start the meal.

If this sounds complicated, well it is!  But you have diabetes as your constant companion for the rest of your life. You will be having at least 2 meals and more usually 3 to 4 every day.  You have plenty of time to experiment to get the best results.

For people on or who prefer fixed basal/bolus regimes

If you are on a fixed basal/bolus regime much of what you have been learning about the versatility of different insulins will be irrelevant to you. You can only use the tools you have after all. One thing that is particularly relevant to you is the delaying or advancing injections in relation to breakfast and your evening meal.

If your pre-meal sugars are high you can give the insulin dose and then wait longer for your sugar to drop before eating. For instance on Mixtard you normally wait 30 minutes before a meal but you could extend this as far as an hour and a quarter depending on how high your sugars are. For novomix or humalog mix the usual instruction is to bolus just before eating. You could inject 14-40 minutes before depending on your level.

The opposite applies to low blood sugars. For mixtard users you would inject and eat right away or earlier than the usual 30 minutes. For novomix/humalog mix users the injection could be delayed part way into the meal or afterwards.  There is no substitute for experimentation and learning from your efforts.

How do I change my insulin regime if I am an NHS patient?

Many US readers will be splitting their sides laughing at the very idea of these detailed schedules for fixed insulin users. Why not learn to carb count and use separate bolus/ basal regimes? Why indeed?

As a UK General Practitioner I realise how difficult it is for patients to change their diabetologist’s mind about what insulin is considered right for them.  I hope you will read about all the different food patterns and insulin regimes so you can consider if what you are doing now is what you really want to do. Are you getting the results you want? How much effort would you be willing to put in to experiment to get the best results for you?

Fixed basal / bolus regimes offer little cover for lunch time meals.  To remedy this you can either eat a very low carb meal at lunch time or ask the diabetologist to give you some rapid acting analogue or regular insulin to inject to cover your lunch.

The diabetic staff  may not want to have to train you in the use of a multiple daily injection regime. They may not want to teach you carb counting. A lot of this has nothing to do with their perception about how you will cope or  whether they like you or not. It is to do with resource allocation in the NHS. NHS staff don’t call it the National Sickness Service for nothing!

Please consider going  through this entire  programme thoroughly.  Prove that you are better informed about what will work to improve your diabetes than they are.

If you get stuck your Member of Parliament or a letter of complaint to the Clinical Director of the Hospital may help.

And the Best of British Luck to you!

Quick Quiz:
1. When a type one is eating in a restaurant it could be risky to to one of these…
a Inject your regular insulin right after ordering.
b Inject your rapid acting insulin right after ordering.
c Ask for vegetables instead of potatoes or rice with the main course.
d Tell the waiter you are diabetic and need food right away if you have been waiting for a time or feeling low.

2. For insulin dependent diabetics they should avoid large amounts of alcohol at one go because…
a It will make them fat.
b It causes acute peripheral neuropathy.
c They will lose their inhibitions and eat sugary food too.
d It can suppress gluconeogenesis and give severely low blood sugars.

3. Type ones need to consider extra insulin when the protein portion to be eaten amounts to…
    a One pound of meat.
    b The size of a man’s palm.
    c The size of a woman’s palm.
    d The size of a boiled egg.
4. Three of these methods can effectively cover protein for insulin users…
     a  Using a single injection of rapid acting insulin such as novorapid/novolog orhumalog.
     b  Using  single injection of regular acting insulin such as actrapid.
     c  Using two insulin injection of rapid acting insulin separated by a length of time. (split bolus technique)
     d  Using an extended bolus of rapid acting insulin in a pump.
5. Ways of extending the length of time an insulin is active also helps to cover three of these foods such as…
     a Pizza
     b Lasagne
     c Mashed potatoes.
     d Chicken korma.
6.  You are using rapid acting insulin to cover your meals. Which three of these techniques could be appropriate around mealtimes…..
    a If your blood sugar was low you could take the appropriate amount of glucose and delay your meal till your blood sugar was back to normal….
    b If your bood sugar was low you could inject 15-30 mins after starting to eat.
    c If your blood sugar was on target you could inject 15-0 minutes before eating.
    d If your blood sugar was high you could inject 15-3 minutes before eating.
7.  You decide to have a  high carbohydrate dessert to celebrate your birthday.  What three measures could you take to minimise adverse effects on your blood sugars…..
    a Eat it early enough in the day when you can exercise vigorously after eating and have plenty of time to check your sugars and correct accordingly.
    b Add a little more insulin than the carb count and your insulin sensitivity would suggest to compensate for the relative insulin resistance caused by high blood sugars.
   c Add lots of unsweetened heavy /  double cream to the dessert to slow the blood sugar spike down.
   d Take the amount of insulin you think you will need but induce vomiting to prevent it digesting fully.
Have you got it?
1.B is unduly risky. Food tends to arrive 2-40 minutes after ordering and you may be putting yourself at risk of a hypo by injecting a rapid acting insulin too soon before the meal. The waiter is there to help you. Ask if you need done specially for you.

2. D is correct. Insulin users in particular should always be moderate about their drinking and eat slowly releasing carb or protein with drink to avoid delayed hypoglycaemia from alcohol. A and C apply to some extent too of course. Prolonged heavy drinking can cause peripheral neuropathy.

3. C is correct. This is around 3-4oz (apparently!) Other visual clues are the size of a deck of cards or a quarter pound burger.
4. BCD are correct. A single injection of rapid acting insulin will tend to spike too early and could give you a hypo soon after you start to eat.  It will have stopped working before the protein has been digested so will give you higher sugars a few hours after the meal.
5. ABD are correct. These have a high fat/protein content and digest fairly slowly. Mashed potatoes on the other hand are converted to sugar very quickly.
6. BCD are correct. With high blood sugars you do need to bring them down for optimal control before eating. Otherwise you would be starting off a meal with a degree of insulin resistance which then tends to require a disproportionately high amount of insulin to sort out after the meal is eaten compared to the levels needed to reduce a highish blood sugar before the meal is eaten. You don’t need to correct for low blood sugars with glucose though. Just eat earlier and  time your insulin a little later…
7.  ABC are correct.  High carb treats can be enjoyable. To eat them very sparingly will enhance the sense of specialnesss and need not damage your health.  The problem of course is if you can’t stop once you start or you eat them too frequently. Some people are best to avoid them completely.
Vomiting to control your blood sugars, your weight or anything else is a bad idea. It plays havoc with your teeth, blood sugars and metabolism.
Unfortunately diabetics have a higher rate of eating disorders such as bulimia and anorexia than the general population.  Sometimes the pressure to be thin can feel so great that insuln injections can be missed so that the calories are passed as sugar in the urine. Life threatening complications such as diabetic ketoacidosis can result. Rapid development of complications such as proliferative retinopathy can appear in a fraction of the time they would with just “average” control.
If you think you could be developing an eating disorder please seek help from your doctor or diabetic clinic. You need expert psychological help and they can get this for you.

Reference Info:
Acknowlegements to Gary Schiener.

Where to Next?
Please all continue onto the section  How To: Help Diabetics Who Can’t Afford Insulin section.