Meal timing may be the secret to intermittent fasting success

A new scientific study suggests that when you eat could be just as important as how long you fast when following an intermittent fasting lifestyle — especially for improving metabolic health, blood sugar control, and body weight.

The research, conducted by scientists at National Taiwan University and published in the journal BMJ Medicine, found that people who consume their meals earlier in the day experience greater health benefits than those who eat later — even when the daily eating window is the same length.

Beyond Just Skipping Meals

Intermittent fasting typically involves limiting food intake to a set number of hours each day without strict calorie counting. Its flexibility has made it one of the most popular nutrition trends worldwide.

However, most earlier studies focused mainly on whether intermittent fasting works. This new research examined a more detailed question: Does the timing of meals during the day influence the results?

Researchers reviewed data from several randomized clinical trials across different countries. They compared eating patterns based on:

• Time of day meals were consumed
• Length of the daily eating window
• Effects on metabolic and heart-health markers

Morning Eaters See Better Results

The findings were clear: individuals who ate primarily in the morning or around midday showed:

• Better blood sugar regulation
• Greater weight improvement
• Healthier heart-related indicators

In contrast, people who concentrated their meals in the evening or nighttime saw fewer benefits.

Timing May Matter More Than Duration

One of the study’s most surprising conclusions was that simply shortening the eating window did not always guarantee better health outcomes.

The least favorable results were seen in participants who:

• Ate late in the day
• Had a long eating window

Interestingly, eating late with a shorter window was less harmful, suggesting that meal timing plays the dominant role.

Working With the Body’s Internal Clock

Researchers linked the results to the body’s biological clock (circadian rhythm). During daylight hours, the body is more efficient at processing food, regulating blood sugar, and managing energy. These processes slow down in the evening.

Lead researcher Professor Ling-Wei Chen said, “Intermittent fasting may be effective and easy to implement, but our results show that when you eat is just as important as how long you fast.”

What This Means for Daily Life

The study reinforces that intermittent fasting can be beneficial — but aligning meals with daytime hours may significantly enhance those benefits. Focusing only on the number of fasting hours while ignoring meal timing could limit the positive effects.

In simple terms, if you want to maximize the health impact of intermittent fasting, eat earlier — not just less often.