Timing of Meals for Diabetes

Having blood sugar that is too high or low can lead to complications. Managing blood sugar levels so they stay in the target range can help prevent or delay the effects of diabetes. Most people with diabetes are aware of how certain foods—particularly those with carbohydrates—can impact blood sugar levels. But what many people may not realize is that meal timing also plays a vital role in blood sugar control in diabetes.

Why Meal Timing Is Important for People With Diabetes

Eating regular meals and snacks with a consistent amount of carbohydrates at the same time every day is essential for maintaining steady energy levels and blood sugar control among people with diabetes.

Eating regular meals is especially important for people with type 1 diabetes and for people with type 2 who are treated with traditional insulin therapy or oral glucose-lowering medications like meglitinides and sulfonylureas. Skipping meals or snacks while on these regimens places a person at risk for low blood sugar, a condition known as hypoglycemia.

Not only will you feel unwell when your blood sugar is low—shaking, sweating, dizziness, hunger—but if it happens frequently, the extra calories required to correct it may eventually cause weight gain. Research has shown an association between hypoglycemia and weight gain in people with type 1 diabetes. 

Skipping meals can also lead to overeating later in the day, which can cause blood sugar spikes.

Low blood sugar can occur at any time during the day. However, people who don't consume regular meals and snacks throughout the day are particularly susceptible to experiencing low blood sugar at night. This is known as nocturnal hypoglycemia. Low blood sugar overnight can be potentially dangerous since you might not realize it’s happening, which can increase your risk of further episodes and make you fatigued during the day.

In some cases, you may not have any noticeable symptoms—known as hypoglycemia unawareness. This is more likely to happen when you have hypoglycemia frequently, diabetes for more than five years, or taken certain medications for high blood pressure. Having low blood sugar during the day without realizing can also be potentially dangerous—especially when exercising or driving.

People who use insulin pumps; take certain oral diabetes medications, such as metformin; or take multiple insulin injections tend to have more flexibility with meal timing and are less likely to experience low blood sugar when skipping or delaying meals.

Meal Timing for Diabetes

While the timing of meals and snacks in diabetes is important, there is no one-size-fits-all meal-timing recommendation. That’s because everyone has different lifestyles, nutritional needs, and health concerns. 

Here is what the latest research says about meal timing for diabetes.

Breakfast

Most experts agree that eating a healthy breakfast after waking up benefits people with diabetes. Not only does a balanced breakfast help you feel full throughout the day, but it also can help control blood sugar.

Eating a larger breakfast followed by smaller meals for lunch and dinner has been linked to weight loss, lower blood sugar, and decreased insulin requirements in people with type 2 diabetes.

Skipping breakfast, on the other hand, has been linked to higher blood sugar levels and weight gain. 

For example, one study of adults with type 1 diabetes found that skipping breakfast increased blood sugar levels during the afternoon and overnight, resulting in an overall higher 24-hour blood sugar concentration.

Interestingly, there was no significant difference in calorie intake between those eating and skipping breakfast. This suggests that those who skipped breakfast overconsumed calories later in the day to compensate for missing breakfast, causing blood sugar spikes.

Another study linked skipping breakfast to obesity among people with type 2 diabetes. Being overweight or having obesity increases your risk for other chronic health conditions, such as heart disease and stroke. While the study did not establish a relationship between skipping breakfast and poor blood sugar control, it is understood that blood sugar can be better managed if you are not overweight or have obesity.

Lunch and Dinner

Consuming a balanced lunch and dinner with the same amount of carbs each day is generally advised to keep your blood sugar and energy levels stable. This is especially important if you take insulin or oral diabetes medications because your blood sugar can drop when you skip or delay a meal.

While there are no set recommendations on exact meal timing, eating an early dinner may be helpful. One study in patients with type 2 diabetes found that eating dinner within two hours of bedtime is associated with obesity and poor blood sugar control.

Snacks

When it comes to snacking, let your blood sugar levels and hunger cues guide you. Traditionally, most meal plans for diabetes include two snacks in addition to three regular meals to stabilize blood sugars. While snacks can prevent and treat hypoglycemia in people with diabetes, not everyone with diabetes—especially type 2 diabetes—may need to snack.

Drinking alcohol can increase your risk of low blood sugar, so you may want to consider having a snack (or keeping one on hand) during these times. 

If you’re at risk for having nocturnal hypoglycemia, having a bedtime snack may help prevent your blood sugar from dropping too low overnight.

Meal Timing and Exercise

Exercising after meals may be an effective way to lower blood sugar levels. Research has shown that people with type 2 diabetes who exercise 30 minutes after a meal can help better regulate their blood sugar.  

Some people with diabetes—especially those who take mealtime insulin or certain other diabetes medications like sulfonylureas—may actually need to eat something before they work out to prevent blood sugar from dropping too low. Your blood sugar can drop low during exercise because your muscles use more glucose, the sugar in your bloodstream, during physical activity.

If you plan to exercise immediately after eating, your healthcare provider may recommend decreasing your insulin dose. You can also eat a small carbohydrate-containing snack before, during, or after exercising. Alternatively, you can exercise before you eat and take your mealtime insulin to lower your risk of low blood sugar and avoid consuming additional carbs during exercise.

Intermittent Fasting and Diabetes

Intermittent fasting is a dietary pattern that involves cycling between periods of fasting and eating. While there are different variations of intermittent fasting, it most commonly refers to a practice where individuals fast for 16 hours each day while consuming all calories during the remaining eight hours. It may also involve fasting for 24 hours every other day. 

Research shows that intermittent fasting is considered a safe and viable option to improve blood sugar control and reduce total daily insulin requirements and weight in people with type 2 diabetes. Several small studies suggest those with type 1 diabetes may also experience similar benefits.

That said, intermittent fasting isn’t for everyone and may have negative side effects in some people with diabetes. 

In particular, intermittent fasting is generally advised against in people with type 1 diabetes because it can increase the risk of high and low blood sugar. However, new studies have demonstrated that intermittent fasting may be safe for those with uncomplicated type 1 diabetes as long as they receive structured diabetes education and use advanced glucose monitoring, such as insulin pump therapy.

Individuals with type 2 diabetes who take insulin or sulfonylureas are also at risk for low blood sugar while on an intermittent fasting plan.

In addition to low blood sugar, other potential risks of intermittent fasting include dehydration, insufficient nutrient intake, excessive hunger, headaches, and weakness.

Certain populations should not engage in intermittent fasting, especially if they have diabetes. These include people who are pregnant or lactating, older adults, young children, people with a history of an eating disorder, and individuals who are immunocompromised.

If you have diabetes and are considering intermittent fasting, be sure to discuss the diet with your healthcare provider to make sure it fits your specific health needs.

How to Develop a Meal Timing Plan That Works for You

Because everyone has different nutrient needs and responds differently to food and medications, it may take trial and error to find a meal timing plan that works best for you.

Here are a few things to consider when developing a meal-timing plan:

• Plan regular meals that include a balance of vegetables, protein, and carbohydrates to keep your blood sugar and energy levels stable throughout the day.
• Balance your carbohydrate intake with exercise as well as the use of insulin and other diabetes medications.
• Keep a record of when and what you eat. Also, note your blood sugar levels before and two hours after meals to see how the foods you eat and meal timing affects your blood sugar. Talk to your healthcare provider about using a continuous glucose monitoring (CGM) device or a blood glucose meter (BGM)—these devices can help measure glucose levels.
• Include healthy snacks, as needed, based on hunger cues and blood sugar levels.
• Check your blood sugar levels before and after exercise to learn how different types of activity impact your blood sugar.

It’s also important to consider work schedules, sleep, and other medications you are taking when creating a meal timing plan.

Working with your healthcare team can help you develop an eating pattern and meal timing plan that best suits your needs.