Why the same foods you eat during the day can lead to belly fat, higher blood sugar & poorer cholesterol levels at night; study has the answer

People who prefer staying up late and eating most of their meals at night may be at a greater risk of developing obesity and metabolic health problems, according to a new study.

Researchers found that night owls were more likely to have a higher body fat percentage, increased belly fat, poorer blood sugar control and less favourable cholesterol levels than people who naturally wake up early.

The findings, published in the peer-reviewed journal Frontiers in Nutrition, suggest that when you eat may be just as important as what you eat.

Night owls more likely to eat high-fat, high-carbohydrate foods late at night

The study found that people with an evening chronotype, commonly known as night owls, tended to consume foods rich in energy, carbohydrates and fats during the late evening and overnight hours.

In contrast, morning chronotypes, or early birds, consumed more of their daily food intake earlier in the day and significantly less at night.

Interestingly, researchers found that both groups consumed similar total amounts of food and calories over the course of the day. The key difference was meal timing, rather than overall calorie intake.

Study links late-night eating to higher body fat and belly fat

The research was led by Rozanne Kruger from Griffith University's School of Allied Health, Sport and Social Work.

The team analysed data from 287 European and Pacific New Zealand women aged between 18 and 45 years, classifying them as morning types, intermediate types or evening types based on their natural sleep and wake preferences.

Women with an evening chronotype consumed less food between 3 am and 9:59 am, but significantly more food between 8 pm and 2:59 am.

Researchers found that this eating pattern was associated with:

• Higher body fat percentage
• Greater abdominal (belly) fat
• Higher android-to-gynoid fat ratio
• Poorer blood sugar regulation
• Less favourable blood lipid profiles

Why eating late at night may affect your health

According to the researchers, eating during the hours when the body is naturally programmed for sleep and fasting may affect the way food is processed.

Instead of efficiently using energy, the body may be more likely to store excess calories as fat, increasing the risk of weight gain and obesity.

The study also found that evening chronotypes consumed fewer protein-rich and micronutrient-dense foods in the morning, while relying more heavily on calorie-dense foods later in the day.

Researchers say meal timing matters

Kruger said the findings reinforce the growing importance of chrononutrition, the science of how meal timing affects health.

"Chronotypes influence our preferences for food intake, our behaviours and our metabolism."

She added: "Both morning-types and evening-types consumed similar amounts of food or energy across the day, but it was the timing of eating that was crucial."

Kruger also emphasised that reducing late-night eating could become an important strategy for improving health among people who naturally stay up late.

"The research highlights that when people eat may be just as important as what they eat. Targeting meal timing, particularly reducing late-night eating, could be an important strategy for improving health amongst people with an evening chronotype."

What is chrononutrition?

Chrononutrition is an emerging field of nutritional science that examines how the timing of meals interacts with the body's internal biological clock, also known as the circadian rhythm.

Previous studies have shown that eating in alignment with natural daylight hours may support healthier metabolism, while frequent late-night eating has been linked to obesity, insulin resistance and cardiovascular disease.

The latest findings add to growing evidence that adjusting meal timing may help reduce the risk of metabolic disorders, particularly for people who naturally prefer later bedtimes.

Study suggests simple lifestyle changes could improve health

Although the study focused on women aged 18 to 45 years, researchers believe the findings highlight the importance of considering meal timing alongside healthy food choices.

For people who identify as night owls, gradually shifting larger meals earlier in the day and limiting high-calorie late-night snacks may help improve body composition and metabolic health.

The researchers concluded that understanding individual chronotypes could play an important role in future strategies aimed at preventing obesity and metabolic diseases.


Disclaimer: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.