Diabetes (Type 2) and Breakfast Consumption
Rania A Mekary, PhD, MSc
Harvard School of Public Health
665 Huntington Avenue
Boston, MA, 02115
(617) 879 5910 / (617) 732 2228 (FAX)
rmekary@hsph.harvard.edu
rania.mekary@mcphs.edu
“Eating Patterns and Type 2 Diabetes Risk in Older Women: Breakfast Consumption and Eating Frequency,”
Am J Clin Nutr. 2013 Aug;98(2):436-43. 50243 (8/2103)
Kirk Hamilton: Can you please share with us your educational background and current position?
Rania A Mekary: I have an interdisciplinary background in nutrition (PhD), statistics (MSc), epidemiology (minor as well as 7 years training and auditing advanced courses in epidemiology and statistics at the Harvard School of Public Health), and kinesiology (minor). I am currently an Assistant Professor in Social and Administrative Sciences at Mass College of Pharmacy and Health Sciences University and also a Research Associate at the Harvard School of Public Health where I have been conducting epidemiological research on nutrition and health disease outcomes such as type 2 diabetes (with Dr. Frank Hu) and colorectal cancer (with Dr. Edward Giovannucci) as well as physical activity epidemiology and obesity outcome for the past 7 years (with Drs Frank Hu and Walter Willett).
KH: What got you interested in studying the role of breakfast consumption and type 2 diabetes incidence?
RAM. I have always been interested in nutrition, physical activity, and other lifestyle characteristics and their relationship with chronic disease outcomes such as obesity and type 2 diabetes (T2D). Growing up as a child, I always heard about the importance of breakfast and that it is the most important meal of the day. Then there were studies showing a positive relationship between breakfast skipping and weight gain. I was curious to see if there was any relationship between breakfast skipping and T2D and whether this was completely due to increased weight gain or to other independent metabolic effects. It is also important to guide physicians who treat patients with T2D on what to advise these patients.
KH: What is/was the hypothesis of why breakfast consumption might affect glucose metabolism and subsequent incidence of type 2 diabetes?
RAM: Increasing evidence indicates that skipping breakfast is directly associated with weight gain and other adverse health outcomes, including insulin resistance and T2D; but studies on this topic are limited and inconsistent. The mechanism behind this is thought to be related to (1) insulin concentration and (2) ghrelin concentration. Insulin concentration needs to be kept at low flat levels rather than at the high spikes that might result from consuming fewer meals with a high glycemic load. Ghrelin concentration increases during hunger. Upon fasting for long hours, insulin levels become too low and ghrelin concentrations become high, which could induce hunger and overeating. Breakfast is a unique meal because it is the time when prolonged fasting ceases. Breakfast consumption, especially if it consisted of fiber rich foods rather than refined cereals, could lead to an improved postprandial glycemic response and insulin sensitivity; hence, betweenmeal hypoglycemia would then be reduced as well as appetite.
KH: Were blood levels of glucose metabolism (HA1c, FBS, insulin) or other biochemical markers taken before, during or after the study? If so did they correlate with breakfast consumption?
RAM: We haven’t validated our findings with these biomarkers yet but we are in the process of doing so.
KH: Can you tell us about your study and the basic results?
RAM: A cohort of 46,289 US women in the Nurses’ Health Study who were free of T2D, cardiovascular disease, or cancer were followed for 6 years. We documented 1560 T2D cases during follow-up. Most of the women (76%) consumed breakfast daily. After adjustment for known risk factors for T2D—except for body mass index (BMI), a potential mediator—women who consumed breakfast irregularly (0–6 times/wk) were at 28% higher risk of T2D than were women who consumed breakfast daily. This association was moderately attenuated to 20% after adjustment for BMI, suggesting that this association was only partially mediated by BMI. An increased eating frequency (>3 times/d) did not appear to attenuate the higher T2D risk associated with irregular breakfast consumption. Contrarily, for irregular breakfast consumption pattern,
increased eating frequency was associated with a higher T2D risk; these associations were partially mediated by BMI.
KH: What are the “side effects” of not eating a regular breakfast?
RAM: Side effects of skipping breakfast according to this study are increased risk of type 2 diabetes that is only partially explained buy weight gain. This appeared in both men and women. In another paper, my colleagues and I also observed a significant association between skipping breakfast and a higher risk of CHD. Take home message: Do Not skip breakfast!
KH: How hard is it to get females to eat a regular breakfast?
RAM: This was not addressed in our study. However, it could be challenging for women who have children in addition to a full-time job to get them to eat breakfast regularly, let alone a healthy breakfast. Time constraints could be a limiting factor. However, I believe with time management, one can always find time to consume breakfast, if not at home, may be on the way to work or at work, based on the transportationtype and the job type. Interestingly, in our study, we found that women who worked full time and did not consume breakfast regularly were at 54% higher risk of T2D than were women who worked part-time and did not consume breakfast regularly (20% higher risk before adjusting for BMI and became non significant after adjusting for BMI). This finding could have been a result of the work-related stress and its association with elevated concentrations of glycated hemoglobin and the metabolic syndrome among persons without diabetes, as shown in other studies. I hope this is convincing evidence for females, especially those working full-time, that it is very crucial they have breakfast every single day.
KH: What are the excuses given of why a regular breakfast is not consumed?
RAM: Again, this was not addressed in our study. But based on my knowledge to the subject matter and my experience as a dietitian who counseled patients for weight loss and other blood problems, the major excuses are time constraints, lack of appetite, misconception of “dieting”, and sometimes religious fasting for a certain period of time.
KH: What are some tips in getting females to eat breakfast?
RAM: Some tips to get females to eat breakfast are the following: 1) Informing them about how breakfast is crucial for health in general. 2) Giving them ideas of what they should or could eat for breakfast (soy milk with fruits, nuts, and low-sugar high fiber cereals; oatmeal with fruits and nuts; omelet and whole wheat bread and some veggies; etc….). It is also important to highlight that coffee or tea alone is not considered breakfast. 3) If they don’t have time to eat breakfast at home, they can eat it on their way to work or at work, whichever is more practical. A handful of nuts, dried fruits, fruits, whole grain cereals along with water are always a good solution to consume breakfast on-the-go.
KH: Were the components of the breakfast evaluated? Was a more protein rich breakfast advantageous? Complexed carbohydrate rich?
RAM: Unfortunately, there was no information of the nutrient composition of the breakfast consumed. However, the Alternative Healthy Eating Index-2010 (AHEI-2010), a score created based on foods and nutrients predictive of chronic disease risk, in addition to other variables related to diet quality, and that are known to be related to T2D such as glycemic load, and cereal fiber intake, were used to reflect overall dietary quality. All these variables mentioned above did not modify the inverse association between breakfast consumption and T2D. These results suggest that breakfast consumption itself confers independent metabolic effects above and beyond the role of dietary quality, particularly because women who consumed breakfast regularly and had the worst AHEI-2010 score did not have a significantly higher risk of T2D. Nonetheless, our results suggest that the combination of poor diet quality (lowest quintile of AHEI-2010 score) with a poor meal pattern (irregular breakfast consumption) is particularly detrimental.
KH: Do we have any idea of the optimal breakfast content if regularly consumed that would reduce diabetic incidence?
RAM: I suggest a breakfast that is high in fiber, protein, and unsaturated fatty acids, low in refined carbohydrates and saturated fat, to be consumed on a daily basis.
KH: How can the public or health professionals use this information?
RAM: The public: Never skip breakfast. No matter how fast the pace of your lifestyle is, think of your health first. For this reason, think of ways how to manage your time and to not skip breakfast. Also, teach your kids the same eating pattern and let them get accustomed to having breakfast daily. Other studies have shown positive associations between breakfast consumption among children and performance at school.
KH: Do you have any further comments on this very interesting subject?
RAM: Never skip breakfast and be a good role model to your children.