Meals and Insulin: Timing Is Key

Medically Reviewed by Michael Dansinger, MD on August 15, 2024
4 min read

If you have diabetes, your main goal is to control your blood sugar. A daily routine of when you eat and when you take your insulin will make it a lot less likely for your blood sugar to peak and valley.

When your doctor discovers you have diabetes, they and your medical team will work with you on:

  • What you should eat
  • Which medicines you need
  • How often you should check your blood sugar
  • The role of exercise and weight loss

Timing is big when you take insulin. For one thing, your meals need to match up with your insulin dose.

What you eat determines how much sugar goes into your bloodstream and how quickly it gets there. Carbohydrates, like bread and potatoes, have the biggest and fastest impact. But when you eat is just as important.

If you eat the same amount of food (especially carbs) at the same time every day, that will help your blood sugar stay on an even keel. There’s another benefit: With well-planned meals at regular times, you’re more likely to eat right. When you feel like you’re starving, you may gobble up whatever’s handy, even if it’s not good for you. Or you may eat too much.

For most people with diabetes, mealtimes should space out through the day like this:

  • Have breakfast within an hour and half of waking up.
  • Eat a meal every 4 to 5 hours after that.
  • Have a snack between meals if you get hungry.

A snack before bedtime may help you.

You don’t have to figure out the menus and times on your own. To help create a plan tailored to you, your doctor may send you to a nutrition specialist. They may call it a registered dietitian. Besides thinking about your nutrition, your dietitian will help match you up with foods that you like and that fit your budget.

If you get your health care through Medicare, Part B covers medical nutrition therapy with a nutrition specialist for people with diabetes. The coverage includes a first session to work out the plan, plus follow-ups to check how it’s working. If you have different insurance, ask whether it will pay for this before you start.

After your doctor and dietitian help you sketch out your meals, you may want to make out a daily action plan that will help you stay on track. Build it around specific things that will be doable. It might say that on certain days of the week, you’ll have a healthy snack (such as fruit) in the afternoon. Or it might say that on certain days of the week, you’ll count the carbs you eat at dinner.

What meds you'll take will depend on what kind of diabetes you have. Your doctor might prescribe insulin, which you’d probably take by giving yourself a shot. Or you may need other medicines that control your blood sugar. You might take those through either pills or shots.

Your doctor may plan your daily doses to match the amount of carbs you’re eating. In that case, your meals and medicine might need to be timed correctly. If they aren't, your blood sugar could spike or drop.

The schedule will depend on what your doctor prescribes. You might just need to take your insulin once a day, or you might need to take it more times.

If your doctor prescribes more than one dose each day, they may include:

  • An overall one called a basal dose.
  • Other doses at mealtimes. Each of these is called a bolus.

Different medicines may need to be taken at different times. For instance, if it’s an extended-release pill, you might swallow one each morning. Other medicines need to be taken while you’re eating.

Along with the right food and medicine, working out can help you control your diabetes. Physical activity will:

  • Lower your blood sugar
  • Lower your blood pressure
  • Improve your blood circulation
  • Burn calories

Your blood sugar tends to be highest about an hour after you have a meal or snack. After you eat, a little exercise will help your body handle that. Why? When your muscles go into action, blood sugar helps fuel them.

You can get the benefit without doing anything strenuous. All you need is 10 to 15 minutes of mild activity, such as:

  • A short walk
  • Walking the dog
  • Shooting a basketball
  • Cleaning up the kitchen

If you want to get into a more vigorous exercise routine, check with your doctor first. Strenuous activity can make your blood sugar fall. You don’t want that. Your medical team can help you build exercise into your daily plans for eating and medicine.

Your meals, medicine, and exercise all revolve around your blood sugar. So you’ll need to test it regularly.

Your doctor will tell you how many times to do it each day. It'll depend on the kind of diabetes you have and how much insulin or other medicine you’re taking.

If you’re taking insulin several times a day, you may need to do a test before each meal and before you go to bed.

If you’re taking long-acting insulin, you may only need to test before breakfast and before dinner.

If you’re taking other medicine but not insulin, you may not need a test every day.

Keep extra-close watch on your blood sugar if you do vigorous exercise. Physical activity can affect your level for hours; even the next day. You may need to check your blood sugar before, during, and after each workout.