Why Do You Administer Insulin Before Meals & Not After?

Taken before meals, fast-acting insulin helps counteract the carbohydrates you eat as you digest them.
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Diabetes is a complicated disease and can be hard to manage. Should you take insulin before or after meals? Is taking insulin at bedtime a bad idea?


There are so many rules that lots of people with diabetes can get it wrong. Here's what you need to know to help keep your blood sugar levels stable.

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Taken before meals, fast-acting insulin helps counteract the carbohydrates you eat as you digest them. This prevents your blood sugar from going up, or “spiking."

What Is Insulin?

As stated by the American Diabetes Association, insulin is a hormone secreted by the pancreas that controls the level of blood sugar (or glucose) in your body. People who have type I diabetes don't produce insulin on their own and must take insulin throughout their lives. Those living with type II diabetes are insulin resistant, meaning that their bodies don't use this hormone properly. That's why they sometimes have to take insulin.


In a July 2017 press release, the Centers for Disease Control and Prevention reported that 30.3 million Americans, or 9.4 percent of the U.S. population, have diabetes. Not all of them require insulin, though. Type II diabetes can often be controlled through a combination of oral medications, diet and exercise.

Insulin removes sugar from the blood and stores it in the cells, where it acts like gasoline in a car engine, providing the energy you need to get through the day. Without this hormone, sugar is not processed and stored as energy. Instead, it builds up in the bloodstream and overflows into the urine.


Read more: List of Foods That Do Not Cause Insulin Release

When to Take Insulin

Establishing an insulin routine is important for people with diabetes. It requires diligence on your part as a patient because the doctor can't monitor you all the time. You'll need to test your blood sugar regularly to discover how insulin works in your body, how much to take and why you should take insulin before or after meals.


Take too little, and your blood sugar will reach dangerously high levels, causing damage in the long term. Take too much, and your blood sugar will dip too low — a dangerous situation that could lead to coma and even death. Learning to administer insulin using a dosage scale along with regular testing will help ensure that you control the highs and lows.


Regular testing will help you understand how your body reacts to things that influence blood glucose levels. Carbohydrates are one factor, but your blood sugar may be affected, either negatively or positively, by your overall health, stress, exercise, how much sleep you get, how much insulin your body naturally produces, your weight and more.


Exercising and controlling your carb intake and the type of carbs you eat can have a profound effect on your blood sugar levels. When you lower your carb intake, get more exercise and improve your sleeping habits, you are likely to end up needing less insulin.

Whenever you make a change to your diet or your daily routine, be sure to document what you did, when you did it and what effect it had on your blood sugar. These notes will help you make the changes necessary to lead a longer and healthier life.


Read more: How to Lower Blood Sugar Levels Fast

Using Fast-Acting Humalog Insulin

When you eat a meal that contains carbohydrates, you may need to administer insulin to prevent a spike. Administering the correct amount of insulin means calculating how many carbs you're about to eat and using the Humalog dosage scale to figure out how many units of insulin you'll need to balance out the carbs.


Once you've added up all the carbs in your meal, you'll need to do a little math. Per the Diabetes Teaching Center at the University of California in San Francisco, depending on your insulin sensitivity (how well your body responds to insulin), you may need to use one unit of insulin for every 12 to 15 grams of carbs.

Let's say you planned to eat steak, a baked potato and steamed broccoli for dinner. Steak has no carbs, so you would need to find out how many carbs are in broccoli and baked potatoes.



According to the USDA, a medium baked potato has about 37 grams of carbs, while one serving of cooked broccoli (a half-cup) has about 6 grams. That's a total of 43 grams of carbs. If, in your case, the Humalog dosage scale is one unit of insulin for every 12 carbs, you'll need to use between three and four units of fast-acting insulin before dinner to balance out the carbs.

It may seem complicated at first, but it's easier than it sounds. Most people with diabetes quickly learn how many carbs are in their favorite foods and can do the math almost without thinking.

Your doctor will tell you the exact number they've calculated for your unique situation. The amount needed can vary from person to person, depending on the type of carbs you're eating and even the time of day. It can be influenced by stress, exercise and other factors. That's why testing is so important for controlling diabetes.

It's important to note that you can take insulin before or after meals. If you can't take insulin before your meal, do it as soon as you can after you eat.

Fast-acting insulin is commonly used for pre-meal injecting. The Humalog insulin website explains that fast-acting insulin starts lowering your blood sugar five to 15 minutes after you take it. To be most effective, you should use it no more than 15 minutes before eating. Fast-acting Humalog insulin stays in your bloodstream for four to six hours, peaking at one to three hours as your body processes the carbs you ingested.

While it's a great idea to research diabetes and insulin use, you should consult your doctor before making any changes to your insulin regimen. To better understand your disease, track everything — meals, insulin intake, blood sugar readings, exercise and water intake. It may seem tedious, but keeping careful track will help your doctor make informed decisions about the amount of insulin you need and how it should be administered.

Read more: How Long After Eating Does Blood Sugar Peak?




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