Pre and Post Meal Testing

Pre and Post Meal Testing

Blood glucose testing is one part of managing your diabetes successfully.

Testing your blood glucose both before and after a meal allows you to see how that meal affects your blood glucose levels and helps you to understand which meals may be best for your blood glucose control.

The most powerful influence on blood glucose levels comes from food. Whether you have type 1 or type 2 diabetes , the peak blood glucose levels are often likely to occur around two hours after meals.

What is pre and post meal blood glucose testing?

Pre and post meal testing allows you to see how your meal and, where relevant, your medication for that meal affects your blood glucose levels

Post-prandial blood glucose measurements are commonly taken two hours after you have eaten.

Pre-prandial and post-prandial means the same thing as before meal and after meal testing.

Why is pre and post-prandial testing useful?

If you test only before meals or only after meals, you don’t get to see how your levels are actually being affected by the meal itself.

The advantage of testing in so called ‘pairs’ of before and after meal tests is that you can see how much your sugar levels have gone up (or even down) between meals.

If your blood glucose levels tend to rise to high numbers after meals, it can leave you feeling tired and also could increase your likelihood of developing complications so there’s very good reasons behind testing before and after meals.

Some people may be put off by seeing high after meal readings but this can represent a chance to re-evaluate your diet or meal choices or to discuss your regime with your doctor or consultant.

What do pre-prandial blood glucose levels show?

What the pre-meal test results show may differ slightly for people with type 1 and type 2 diabetes

Type 1 diabetes: Pre-meal tests are a good way of seeing whether you have injected the right size of dose for your previous meal. If it’s a pre-breakfast test, the result will show you whether your insulin to carbohydrate ratio was correct overnight.

If you have injected too little insulin, you will see your pre-meal results are higher than they should be before your next meal. If you have injected too much, your test results will be too low before your next meal. If you have questions about insulin dosing , write these down and discuss these with your healthcare team.

Type 2 diabetes: Your pre-meal tests can provide an indication of how well your body is coping, with support from any medication , with your previous meal. If you have high results, it may indicate that either the carbohydrate you are eating is too much or that your medication may not be adequate.

If you have questions about your results and what they may be showing, ask your healthcare team.

What are the recommended pre-meal blood glucose levels?

The NICE guidelines for pre-meal blood glucose level targets are:

  • Type 2 diabetes: 4 to 7 mmol/l
  • Type 1 diabetes: 4 to 7 mmol/l
  • Children with type 1 diabetes: 4 to 8 mmol/l

What influences post-prandial blood glucose levels?

Your post-prandial blood glucose levels will largely be influenced by the meal you have eaten, the type and dose of medication you take and how sensitive your body is to insulin. Most people with diabetes can expect to see a rise in blood glucose levels for their after meal results.

The NICE guidelines state the following post meal blood glucose level targets:

  • Type 2 diabetes: under 8.5 mmol/l
  • Type 1 diabetes: under 9 mmol/l
  • Children with type 1 diabetes: under 10 mmol/l

You may want to discuss your personal targets with your healthcare team.

What if my test strips are limited?

If the number of test strips you can have is limited, it makes making the most out of the test strips you have all the more important.

You may not need to test before and after every meal, but any pair results you can take will greatly help your understanding of how the meals are affecting your levels.

Page 1 of 2: Patient perspectives on Pre and Post Meal Testing >>

I have found the best advice for healthy eating is to start with the diabetes web site, then ask your doctor to include you in one of the Desmond courses, which will show you what foods do to you. I’ve found it’s not exactly what, but how much of what you eat or drink. Good advice though.
Posted by Clive S Williams, Hampshire on Wednesday, June 13, 2012
Hi, I have just been diagnosed as pre-diabetic type 2. The nurse at my surgery has given me dietary advice, but told me to include some carbs in my meals (I had been on a healthy eating plan for some months, leaving as many carbs/ starches out of my diet as possible as I am aware that breads etc cause bloating, difficulty losing weight) now I have added them back in I am crashing after lunch, falling asleep, very low etc. I was not told about personal testing (just to go back in 3 months) nor was I given any advice about prescriptions? Am I just expected to guess at what foods are working for men, or allow the surgery to experiment with my diet/ bg etc…. Am I entitled to the same dispensation as a diabetic or what, I feel like I’m in no man’s land?!
Posted by Lynda, Milton Keynes on Saturday, June 09, 2012
I was having real problems getting my blood levels down but was only being tested periodically by my GP. I complained to him that I was eating all the right things and in moderation but without a testing kit, it was akin to being told to drive for 100s of miles at 32mph without a speedometer. He saw my point and pescribed a testing kit. 12 months later and what a difference – I hit 6.2 (my target) virtually every day. It has also allowed me to eliminate some foods that one would think okay but don’t work for me. The moral is, get a testing kit from your GP and don’t take no for an answer.
Posted by Fergus, Wiltshire on Wednesday, March 07, 2012
I have been type 2 for 1 year now. I have always been fit and underweight all my life and I cannot get a grip of my sugar levels. I am trying to put weight on but I am in a catch 22, I am wasting away. If I eat more my levels increase. If I go to bed having eaten 2 or 3 hours before, I wake up and have a high level reading even though levels were normal on going to bed. I never have low readings unless I do not eat and exercise but then I feel a bit unwell. I see no solution and no help from local GP system. I think I have fallen through the net as they do not ask me to come round for checks anymore.
Posted by Peter Lamont , Inverness Scotland on Sunday, January 01, 2012
From all the correspondence I see on your web site it is obvious that the medical profession sees Type 2 diabetics as being mainly self inflicted and in these straightened financial times not something that deserves money being spent on as its the patients own fault. (A similar attitude to those who smoke or drink) Fortunately my doctor is more enlightened than those mentioned above and prescribes sufficient test strips to allow reasonable testing. Why is Diabetics UK not issuing firm guidelines on this subject and forcing, through parliamentary lobbying if necessary, that these guidelines be adopted universally by the medical professing instead of money being the guiding criteria. Fortunately I am of the correct BMI, drink virtually no alcohol and do not smoke. Type 2 which I have had for several years now and now being treated by insulin and tablets is hereditary in my family so perhaps he has more sympathy with my situation than those who cause it by obesity and poor diet.
Posted by Homer, Durham (Durham – Cumbria border) on Sunday, October 16, 2011
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