Meal Timing and Frequency Correlate with Changes in BMI, According to 7-Year Review of 50,000 People in the Adventist Health Study 2

WASHINGTON—New research published in the Journal of Nutrition finds meal timing may be one way to reach and maintain a lower body weight, based on feedback from 50,000 participants in the Adventist Health Study 2 (AHS-2) who participated in a 7-year follow-up study. The researchers analyzed data on meal timing and meal frequency, in relationship to changes in body mass index (BMI), a measure of body weight.

Lead author Hana Kahleova, M.D., Ph.D., completed the study as a postdoctoral research fellow at Loma Linda University and co-authors the study with Gary Fraser, Ph.D., a professor at the Loma Linda University School of Medicine and Public Health and the director of AHS-2, and researchers with the Loma Linda University School of Public Health.

Dr. Hana Kahleova, director of clinical research at the nonprofit Physicians Committee, finds AHS-2 participants with the lowest increase in body mass index (BMI) participate in four behaviors: 1. They eat breakfast instead of skipping it; 2. They make breakfast the largest meal of the day; 3. They don’t eat snacks; and 4. Their overnight fast is longer and may last 18 hours. 

The study participants with the highest increase in BMI consumed more than three daily meals, which means they ate snacks, and ate their largest meal after 6 p.m. 

“The ancient advice to eat breakfast like a king and dinner like a pauper has new science to back its claim,” says Dr. Kahleova. “Based on previous research, we continue to find our body’s metabolism works most efficiently earlier on in the day.”

For those who want to reach and maintain a healthy weight and boost insulin function, Dr. Kahleova recommends eating breakfast and lunch, spacing the meals five to six hours apart; making breakfast the largest meal of the day; skipping snacks and dinner; and fasting for 18 hours, say from 2 p.m. to 8 a.m. For an added edge, based on prior research, she recommends exercising for an hour each day and building meals around nutrient-dense, plant-based foods.

“As a clinical researcher, my day changes on a moment’s notice and I understand overnight fasts may not fit into everyone’s lifestyle, at least not every day,” says Dr. Kahleova. “However, by understanding our biology, we can rearrange our meals so that they work for us, instead of against us, to fast-track our health and weight-loss goals, whether it’s losing five pounds or reversing a family history of type 2 diabetes.” 

In the discussion notes, the researchers mention this study supports previous findings that suggest regular breakfast consumption may help increase satiety; reduce total energy intake; improve overall dietary quality, measured by increased consumption of fiber- and nutrient-dense foods, which are often consumed at breakfast; reduce blood lipids; and improve insulin sensitivity at a subsequent meal. Compared to eating meals in the evening, breakfast may help boost insulin function and provide a steady release of energy throughout the day.

The study used a linear regression analysis, adjusted to measure important demographic and lifestyle factors.

The study strengths include analyzing a large, diverse population with a variety of BMI ranges—over a 7-year period—and capturing precise meal times and BMI values. Potential weaknesses include a correlative analysis, lack of information about the number of calories consumed per meal, and the ability to differentiate between intentional and unintentional weight loss.

The full text of the study, entitled “Meal Frequency and Timing Are Associated with Changes in Body Mass Index in Adventist Health Study 2,” is supported by grants from the National Cancer Institute, the World Cancer Research Fund, and the Ministry of Health of the Czech Republic.

The study will run in the 2017 print edition of the Journal of Nutrition.

For an interview with lead study author Dr. Hana Kahleova, please contact  JMcVey [at] pcrm.org (Jeanne Stuart McVey), Media Relations Manager, 202-527-7316, 202-686-2210, ext. 316.

For an interview with AHS-2 director Dr. Gary Fraser, please contact Briana Pastorino at 909-558-8357 or bpastorino [at] llu.edu (bpastorino[at]llu[dot]edu).

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Hana Kahleova, M.D., Ph.D. is the director of clinical research for the nonprofit Physicians Committee. In addition to studying the health benefits of a plant-based vegetarian diet, Dr. Kahleova is passionate about studying external factors that shape our metabolism.

Loma Linda University Health includes Loma Linda University’s eight professional schools, Loma Linda University Medical Center’s six hospitals, and 800 faculty physicians located in the Inland Empire of Southern California. Established in 1905, LLUH is a global leader in education, research, and clinical care. It offers over 100 academic programs and provides quality health care to 40,000 inpatients and 1.5 million outpatients each year.