Meal timing with diabetes: Why when you eat matters (not just what)

COVID-19 has changed the way we eat. Over a year into the pandemic and 72% of Americans say they’re still making at least one change in the food they eat or the way they source or prepare it. As someone with prediabetes or diabetes, you have likely heard this: what you eat has a dramatic effect on your blood sugar control, heart health, disease risks and even protection from severe COVID-19.

But the evidence says WHEN you eat matters, too.

Keep a consistent, evenly spaced meal schedule.

Everyone with or at risk for diabetes needs a healthy eating plan that is tailored to and works specifically for you, based on your unique lifestyle and health history. Your food preferences, what you eat, where and when, can be tweaked to make a big dent in your own personal diabetes and weight management goals. It just takes a little time and practice (and sometimes working together with someone like me), as there’s just no one-size-fits-all plan.

One constant, however, is timing meals—and smart snacks—with a consistent amount of carbohydrates on a consistent schedule throughout the day (say, three main meals 4-5 hours apart at the same or similar times of the day). This helps keep your blood sugar levels more stable, your hunger cravings under control, and your body loaded with the energy it needs for daily activities and self-care.

Wait too long between meals and your blood sugar can dip. Splurge on one big meal and your blood sugar can rise. Skip meals frequently and you can lower your metabolism, making it actually harder to manage blood sugars and weight.

Studies suggest one reason why regular mealtimes are optimal for your health: they help regulate your body’s internal circadian clock. This clock runs in the background to optimally carry out your body’s essential functions like sleep and digestion. Disrupt this clock and it’s believed to contribute to chronic conditions like cardiovascular disease or type 2 diabetes, and it also makes you more susceptible to viral respiratory diseases.

Set eating interval durations.

Eating interval duration is the time between your first and last eating occasion. One small investigation found that, without changing any other dietary habits, men at risk for diabetes who ate what they normally ate but within a restricted 9-hour eating interval showed improved glucose tolerance regardless of when they began their first meal.

Move breakfast earlier.

Eating start time is another strategy that can benefit cardiometabolic health. A study in Chicago recently discovered that adults who ate their first meal before 8:30 a.m. each day showed lower insulin resistance compared with those who ate after 8:30 a.m., regardless of their eating interval duration.

Don’t make a habit of eating too late at night.

Similarly, your last meal might be moved intentionally earlier too, say 5-6 p.m. A 2020 observational study at Johns Hopkins Bayview Medical Center found that adult subjects who ate late at night (10 p.m.) burned as much as 10 percent less fat when compared to those who ate an early (6 p.m.) dinner—and late eaters had almost a 20 percent higher blood sugar peak.

Try your own experiments.

No matter what your current healthy eating plan is, practice being your own diabetes detective.

1. Keep a record of what, how much and when you eat, along with what your blood sugar level is before and two hours after you eat.
2. Repeat for a few days.
3. Look at your record and ask yourself: how might a specific food or meal be affecting my blood sugar level? How might timing be affecting it? How might eating more or less often be affecting it? Do I need more meal planning help?

Remember: as with when you exercise or take prescribed medications, what AND when you eat affects everyone uniquely! One of the largest diet inquiries of its kind confirms that different people’s blood sugar levels respond very differently when given exactly the same real-life meals.

“Think of diabetes management as a series of experiments that can help you maximize your self-management,” recommends the American Association of Diabetes Care & Education Specialists. “They are not a pass or fail exercise and do not have good or bad judgments associated with them. By experimenting, you learn more about YOUR diabetes and what gets you the results you want.”

Need help with your present nutrition or meal planning needs? Try talking with a registered dietitian or certified diabetes care and education specialist near you.