Ratio of Basal to Bolus

What is your Basal to Bolus ratio? Does anyone use anything other than 50/50?

@lewiscor Lewis, since the 1970’s when I worked under the direction of endocrinologists/scientists developing what was to become called MDI - the basis for the 1980’s DCCT Worldwide Study - my ratio has been closer to 70/30; that is 70% bolus [food + correction] and 30 % basal.

Thanks Dennis for sharing your experience. That is about what my ratio is (75% Bolus & 25% Basal), and has been since I went on a pump maybe 13 years ago. I have been a T1D for 49 years. I am going to a new Endo. and it looks like he wants me to change to 50/50 ratio. I am not sure I see the logic in changing.

Lewis and Dennis (@lewiscor & @Dennis),

When I first read your post I thought, “Holy cow! You’re going to get hammered to your knees!” And then I re-read what you have both posted and realized my insulin need is (and always has been) “upside-down” from the “standard.” Now remember, I need anywhere from about 14 to 19 units of Humalog per day, and my basals are generally 80% of the total (usually between a 1 and 1.2 unit bolus to cover a meal). So I’m scooting along at about a 20/80 ratio (20% bolus/80% basal).

I don’t have a clue what your new endo is wanting to see. But 50/50 would have me on quite a roller-coaster. And 70/30 would, well, it just wouldn’t work very well for me.

Good luck! I hope things work out very well whatever the end result.


@lewiscor Lewis, your “new endo” read a book - or a paper written by a diabetes expert.
About ten years ago an endo I was seeing showed me that and told me that I should try to get close to 50/50. I got about 2% closer and found the 50/50 wasn’t for me.

I currently use 6.5 units basal [32.4%] and 12.15 units bolus to cover the 200+ grams of carb I eat. That is the 7 day average my pump just told me.

According to my pump history, my 30-day average is 82% basal and 18% bolus. I eat low-carb (below 40 grams a day) and my A1c is 5.9%. Typically I stay below 30 units of Novolog a day.

I’m more of an 80/20 80% basil 20% bonus, but it comes down to how you eat how often you eat how many carbs you eat and how active, I maintain a very low carb diet, snack on small meals through out the day which matches activity. I’m active most everyday so having a constant basil that supplies the majority of insulin suits my purpose. Also I exercise some every day biking or dog walking and usually preload some carbs prior to exercise. I’ve heard several patient educators talk about the ratio as if there is some magic to the formula, I think that’s naive there’s so many other factors that affect your need for insulin and when you need it.

I had adjusted my pump settings a few years back to something that worked for me. My A1c dropped from over 7 to 6.2. My doctor was thrilled. Then I switched pumps and the gal who trained me said my basals were too high. She adjusted my settings to the “standard” 50/50, and I went back on the roller coaster I was previously on. Unfortunately, I’m not good at keeping track, so I’m back to trying to get the settings right again. So my advice/question is, if your current settings are working, why change it?


PS: Something I realized I left out! My doctor had moved, closing the office here. So, I was with a new endo at the time.


Mine tends to be roughly 50/50, but since I’m on MDIs I don’t keep as careful track as I probably should. I agree with @pamcklein–as long as it’s working for you, I don’t see a reason to change it! :slight_smile:

You’ve got that right Pam @pamcklein, if it is working [effectively and well], why make changes. That is the question I asked an endo who suggested that I ‘try to get closer to 50/50’. As I said before to a question as to why an endo was recommending 50/50 that it was because that doctor had read some book or paper - and didn’t have the wisdom to know that there isn’t any one ration that will work for app PWD. If there was, you can rest assured that there would be only one “fits-all” insulin on the marked with a set dose for ALL users.

Pam, a way to keep track of your pump settings and be able to easily go back to ‘something that worked’, is to “save pump settings” on your computer when you go into the information viewing program established by your pump manufacturer. For all the years I used Medtronic pumps I have periodically saved from CareLink program my settings in a date format [yyyy-mm-dd]; now with Tandem I use the t-Connect program. I also keep a copy saved on my cloud-drive [Microsoft “One Drive”] just in case something happens to my pump or settings when I’m traveling. One time I had a pump failure when away for a Board meeting and Medtronic sent a replacement pump to the hotel where I was staying - my on-line settings were a life-saver.

The 50/50 concept is the basis for initial treatment for many doctors. A study I read recently suggested that basal rates should be 30-40% in people who have higher carb diets, while “American” diets higher in fats benefit from higher basal rates. This has to do with carb uptake. My son, for example, is very into computers, and needs a higher basal rate during the day to deal with his meals because he’s a bit sedentary (at least over the summer). His pump says he’s 72% basal, 28% bolus. We also enjoy homemade focaccia, which is a very heavily oiled bread, and he has developed a habit of dosing for the carbs with an extended bolus from his pump that spreads the dose over 4-5 hours(!!) because the olive oil keeps those carbs from flooding his system. There are actual formulas that can be used to calculate your dosing based on your weight, but even these are not perfect.

Unfortunately for doctors and research studies, every patient is an individual, and ultimately you as the patient will have to find what works for you. If your numbers are well controlled, and you feel well, then I don’t see any reason to change your insulin regimen. The real work of tracking your eating and activity habits will help you understand how your insulin regimen needs for be adjusted for your body. This can change over time, of course.

Getting comfortable with a new provider can be a bit of a process, and requires lots of open communication, and a willingness to try new or different things sometimes. Best wishes for a good working relationship.

In my opinion, who cares what the ratio of basal:bolus is? The one and only thing that matters with basal is that your blood sugar stays constant if you aren’t eating. Period. It’s worth checking every 6 months to a year if you aren’t recently diagnosed. My basal rates change slightly with the seasons. As for bolus, it’s only job is to bring your sugar back to starting point in 4 hours. Period.

And so if it’s 90:10 or 10:90 or 50:50 or whatever… and it’s working… then DO NOT CHANGE ANYTHING. If some kid doctor or newbie pump trainer talks you into making changes, it’s still ultimately up to you. Cheers and good luck :four_leaf_clover:

I agree with you Joel @T1dadandICU-RN, if it works, why break it. Very few doctors that I have worked with in over 60 years with diabetes have ever lived one day with TypeOne. Before giving advice, like advising a patient to live with a 50:50 basal:bolus ratio, an intelligent doctor would first observe and ask questions.

Each of us is different as far as amounts of insulin we need, and as @Joe says, what difference does it really make if one’s basal bolus ratio is 50:50, 70:30, 30:70 as long as it is the correct ratio for you.

I periodically validate my basal rates by fasting; for instance, I will eat a “normal supper” on a day where my activity level is normal and will not eat again until after noon the following day. If my BGL remains within target [100 to 140 mg/dl] during that period without need for correction dosing or eating anything containing carbohydrate then I know my basal rates are correct. This paid off well for me during surgery when I wasn’t permitted to eat after mid-night [a senseless / without thought requirement]; I was prepped and laying on the table for my surgery scheduled for 7 AM which was delayed until 11 AM. My BGL remained in range even with my anxiety and frustration.