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Is there a “best time” to eat food after insulin injections? I want to reduce my BG spikes as I’ve read that it can also lead to other health risks. I’m wondering if the timing plays a role or not for my BG spikes? If not, then what are some other ways of reducing the variability of BG spikes (large BG differences in a short period of time)?
 
If you are basal/bolus insulin, a prebolus is a good idea...ie injecting some time before eating.
I am on novorapid and find a prebolus of 15 min works for most meals, though its 35min at breakfast
 
Insulin works at a set speed - you can check out the activity profile graphs although it will vary from person to person and (to a lesser extent) what is your BG.
The speed at which the carbs from your food hit your blood as glucose varies depending upon what you eat. As you are probably aware, there are some fast acting carbs that we use for hypo treatment which can start working in 10 to 15 minutes. But when you eat high fat high carb meals like curry or pizza or pasta, it can take hours for the last of the carbs to join your blood.
Then there is different times of the day. Typically, we are more insulin resistant in the morning so insulin can take longer to work with breakfast.

The initial guideline was to inject 15 minutes before eating but this is only guidance because as you can see from above, with all the planets aligned with your BG at optimum level and with the "perfect carbs" the carb absorption peak may happen at the same time as the insulin activity peak. But it might not.
And, it assumes you are not taking one of the ultra fast insulins like Fiasp because these can start working instantly and cause a hypo if you take your dose 15 minutes before eating.

So, you need to work out how fast your insulin works for you and the food you eat.
It is always useful to start with a consistent meal like breakfast and slowly move the injection time slightly earlier (no more than 5 minutes per day) than you eat and find out how this affects your peaks.

But remember - everyone has a BG spike when they eat including people without diabetes. Do not aim for a flat line and do not let diabetes control your life.
 
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commit said:
Is there a “best time” to eat food after insulin injections? I want to reduce my BG spikes as I’ve read that it can also lead to other health risks. I’m wondering if the timing plays a role or not for my BG spikes? If not, then what are some other ways of reducing the variability of BG spikes (large BG differences in a short period of time)?
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Absolutely, @commit. The timing between bolus and food plays a big part in getting that "utopia" of digestion and conversion of food into blood glucose to be simultaneous with the availability of insulin. Alas knowing that is the easy part. Achieving it is less so. Ultimately it's not something that has a simple or even repeatable "formula".

One factor is your own natural resistance to insulin. For many of us we are more insulin resistant first thing in the morning than by early evening. For you as a recently diagnosed T1 you have the extra complication of potentially still having some "home-grown" insulin that may also be "helping" just after you've committed to an extraneous dose (or not appearing when you've assumed it will because it did yesterday).

Another factor is the meal itself. The mix of carbs, fats and proteins affects the overall glycaemic index of whatever is being metabolised. So a breakfast centred on cereal, milk and perhaps fruit would have a different GI to toast and scrambled eggs. Personally I have at least 3 different standard (but very different) breakfasts and one of those is always my go to choice if I need my BG behaviour to be helpful and reasonably predictable after my breakfast because I have a commitment or a long drive, etc. But this variable GI factor applies to each meal through the day. Extra fat content in particular is a big player, which is why you will often read that there is the pizza effect; the delay in digestion because of the nature of a finger-licking great pizza.

A 3rd factor is how much exercise you have been doing yesterday, earlier today or planning to do later today. In a way that exercise is an extension of the insulin resistance factor. Exercise affects your ability to achieve some regulating of your metabolism

However there are still a sizeable number of other factors such as the weather, stress, overall health (particularly if this is changing - such as an incoming cold that you don't yet know is happening but your body does and is trying to fend that off). And, of course what insulins you are using, with their different theoretical performance criteria.

There is, from my experience so far, no simple answer. BUT we are these days blessed with having CGM and thus able to exploit the trial and learning that is an essential part of working out "what is right FOR YOU". We are all different and how each part of the medley of factors affects you is something only you can sort out - not least because you might have circumstances where you would prefer to have a safety margin of a significant BG rise ahead of an important event or circumstance.

Incidentally I try not to call my BG rises "spikes". They certainly look like spikes when seen on my phone screen in portrait, but much less so when displayed in landscape (which my Dexcom G7 offers as part of the app). Viewed in landscape apart from not being particularly spiky they show a distinct variation in how fast these unwanted rises appear and how long they take to dissipate. Seeing the bigger picture in landscape also helps keep all of this in better proportion; somehow "spikes" seen in portrait are more intimidating than seen with a better horizontal time-line axis. Before CGM I didn't know they were spikes - I just knew that I spent almost a year on the BG roller coaster as I raced from hypo to hyper several times a day and I had none of my current background understanding of how I might slow the playground toy sufficiently to allow me to get off it!
 
Others got here before me. I might have also added one further factor is that Diabetes doesn't know there are supposed to be rules or a framework we can cling to and sometimes (too often for my preference) one is wearing the wrong coloured socks - without knowing the socks are wrong and nothing is explainable. It's just a mystery!
 
Really, you have to try it out....perhaps a 5 min prebolus, then 10, then 15 etc til you fnd something that works for the meal, indulin, time of day...have you seen the ino on minimising spikes pinned to the top of the food board?
 
As everyone else has said it depends on what you're eating and personal circumstances. I was told to take my rapid insulin 20 mins before my meal but I kept getting hypos. I now generally take it with my meal and if its a high fat or 'complex' (i.e. lots of different elements) I often take some more about an hour or two afterwards. I think rises afterwards are inevitable unless you have a very regimented diet which personally would be boring.

There are health risks of being continually high but general view seems to be the occasional high is generally ok. What that number is seems to be up for debate. My consultant felt 12 was too high but just about everyone else on this forum disagrees or at least that its not practical. I tend to take a correcting dose at 13/14 if the trend is upwards. Having said that I'm pretty new to this so may have a completely different view next month.

If you have a glucose monitor your 'time in range' should give you a rough idea of how things are overall rather than just looking at the occasional 'spike'.
 
I used to spike up to 15 after breakfast every morning prebolusing 20 mins before I ate with NovoRapid and ten came crashing back down to 5 later and it was not pleasant. I experimented with increasing the prebolus time and found that for me at breakfast time with NovoRapid I needed over an hour, usually about 75 mins to prevent the spike and this was with a low carb breakfast of creamy yoghurt with berries and seeds. Other times of day I needed 20-30 mins.

I eventually switched to Fiasp and that reduced it down to about 45mins for me although Fiasp seems to be much more dependent on your waking BG than NR was and if I wake in the 4s or low 5s I may only need 20-30mins. For me the important thing on a morning is injecting before I get out of bed because once my feet hit the floor, my levels are rising fast and any insulin I inject after that has a strong tide of glucose to overcome from my liver before I even think about breakfast. My morning routine is that I inject my morning Levemir and 1.5-2 units of Fiasp to cover Foot on the Floor plus whatever I will need for my breakfast if I am having breakfast and then get up and start my morning routine. This works a treat for me and I usually have barely any rise at all at breakfast and almost always under 8. Other times of day, as others have said, it depends on BG levels before the meal and what I am going to have. You have to experiment to find what works for you at different times of day, by gradually increasing the prebolus time for different meals until you bring the spike down t whatever is acceptable for you with your insulin and the food that you are eating and what you are going to be doing after the meal, like exercise.
 
It’s the good old diabetes answer (also data protection) “it depends”

I go with 15ish minutes, sometimes it’s more stubborn in the morning. If I’m over 12 I wait longer until I see it start to drop but make sure my food is ready to eat.

If I am in my period or it’s warm my insulin seems to work better so less time.
 
I aim for 30 min in the morning, 20 for lunch and evening meal, but.. it depends on all those other variables that @helli mentioned, and also on me remembering to do it ( I am better at it when OH is cooking, but sometimes forget when I am cooking) . I find when I am eating out, apart from a few local restaurants that ‘get it and deliver my meal 20 min after I have bolused, I will wait until the food is in front of me. There will then be a bit of a bigger rise but safer than going hypo if the meal doesn’t arrive.

So it is a good idea to pre-bolus and the timing for you depends and will be individual to you.
 
SB2015 said:
I aim for 30 min in the morning, 20 for lunch and evening meal, but.. it depends on all those other variables that @helli mentioned, and also on me remembering to do it ( I am better at it when OH is cooking, but sometimes forget when I am cooking) . I find when I am eating out, apart from a few local restaurants that ‘get it and deliver my meal 20 min after I have bolused, I will wait until the food is in front of me. There will then be a bit of a bigger rise but safer than going hypo if the meal doesn’t arrive.

So it is a good idea to pre-bolus and the timing for you depends and will be individual to you.
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I am better if I am cooking, no OH never gives me usual timeframes / or notice.

And I had forgot about eating out and takeaway deliveries, those things can be 5 minutes or over an hour.

I had that situation at a cafe, back in May, I know they are quick normally and I ordered a coffee (which I have to cover with insulin) and my husband went to order so I took my insulin and he cam back after a few minutes and said we weren't ordering due to wait times and items they didnt have. My pump was still going and they said 15 minutes for the coffee. I had enough sweets and carbs on me to cover most of the insulin taken but I was in such a flap. I felt ill. Never doing that again. I might part dose if having a meal out and I know the food is ordered and the place we are eating, otherwise as you say as it arrives.
 
We've just come back from local garden centre, had lunch there & bolused as we sat down, they take your food order then there a wee queue for hot drinks so time you get them food isn't so far away.

After sitting for 10mins today food arrived so insulin got a head start, if your a regular in places you kinda get to know how long meals take from ordering, if it's somewhere new tend to wait for it to arrive.
 
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