Meena Shah’s Research Work Includes a Heavy Emphasis on Mentorship
Dr. Meena Shah, chair and professor of kinesiology, has a number of studies on dietary and exercise interventions with interesting results. Her work on menu labeling garnered headlines from national and international outlets, including The New York Times, NPR and the BBC.
After receiving a Bachelor of Science in nutrition and dietetics from Robert Gordon’s Institute of Technology in Aberdeen, Scotland, Shah earned her PhD in nutrition from the University of London, England. In 2001, she joined the faculty at TCU, where the teacher-scholar model is an ideal fit for her.
“I try to integrate research and teaching activities,” she says. “Students become more engaged with that approach. Some of them end up becoming part of my research team helping to implement what we have discussed in the classroom.”
Shah examines the effects of exercise and diet intervention on cardiovascular risk factors such as body weight, lipids, lipoproteins, glycemic control and blood pressure. She also evaluates the effects of eating behavior and the eating environment on calorie consumption.
“I do a lot mentoring of students — and I love it,” she says. “I really like to have them go through the whole research process — coming up with a strong study design that is publishable and then implementing the study. I also like to see them work well together as a team. I have several students, both graduate and undergraduates, working on different aspects of a study so that they are all collecting data on a piece of that study.”
Student published work
“We have implemented many interesting studies in our labs,” Shah says. “Every single study that my graduate students have performed has been published, and we have had a few undergraduate publications as well.”
On these student-led studies, Shah has collaborated with several TCU faculty — including Drs. Joel Mitchell, Jonathan Oliver, Phil Esposito, Robyn Trocchio, Debbie Rhea, and Todd Castleberry from Kinesiology; Drs. Lyn Dart and Jada Willis from Nutritional Sciences; and Dr. Dennis Cheek from Nursing — as well as Beverley Adams-Huet from UT Southwestern Medical Center.
Among the earlier work from her lab, graduate student Jane Copeland led a study evaluating the effect of eating speed on energy intake. They found that eating slowly lowered energy intake in normal weight — yet not overweight individuals — and reduced hunger ratings in both groups later on.
In a subsequent study in this area, another graduate student, Kelli Crisp, evaluated the effects of eating speed on gut hormones that cause hunger and fullness.
“There are several hormones released by our gut that make us feel either full or hungry,” Shah says. “Although eating speed may affect calorie consumption, it did not affect the hormones that control our food intake.”
They summarized that when people eat slowly, they may eat less food because they are more mindful of the feeling of fullness.
The truth about menu labels
In another study, Shah and graduate student Ashlei James evaluated the effects of menu labels on food choices and food consumption in young adults, mostly TCU students. Specifically, they compared menus listing only the food items, menus that included calorie information next to each item, and menus with exercise labels detailing how much time brisk walking would be required to offset the calorie consumption of each item.
“It was the exercise label that was effective in helping to choose and consume lower-calorie foods — not the calorie label,” she says. “People could relate to exercise labels. If you’re not familiar with calories, you may not understand what 500 calories mean. But everybody understands what 90 minutes of brisk walking means.”
Led by graduate student Brooke Bouza, a similar study in a Hispanic population did not find that exercise labels improve food choices.
“The Hispanic population was older and less well educated and health-conscious compared to the younger TCU population studied earlier,” Shah says. “These differences may have contributed to the disparate findings.”
Fat vs. protein
In two separates studies, graduate students Brian Franklin and Manall Jaffery pitted high-protein meals against high-fat meals — specifically monounsaturated fat — and their effects on blood glucose control and lipid and lipoprotein responses in participants who were obese or lean.
“We looked at a number of hormones that affect blood glucose — not just insulin,” Shah says.
Participants were given one of two drinks: In the high-protein drink, about 32% of the energy came from protein. In the high-fat drink, 35% of the energy came from fat and 21% from monounsaturated fat. Researchers did hourly blood draws over the next three hours to measure participants’ blood glucose and a number of hormones that control blood glucose level. One such hormone, glucagon-like peptide-1 (GLP-1), is an incretin hormone and plays a major role in insulin secretion.
“What we found was that in these obese subjects, the high-protein meal led to higher GLP-1 and insulin production compared to the high-fat meal,” she says.
When the researchers went a step further and looked at insulin sensitivity — or how well participants’ cells responded to insulin — the meal high in monounsaturated fat was the better option.
“So for obese people who do not have diabetes, a meal high in monounsaturated fat may be more effective at controlling blood glucose compared to a high-protein meal,” Shah says.
The same study also found that the high-protein meal resulted in lower triglyceride production compared to the high-fat meal in obese subjects. However, the particle sizes of the good cholesterol (HDL) and bad cholesterol (LDL) were smaller on the high-protein meal compared to the high-fat meal, she says.
“A small HDL is not as cardio-protective as a large HDL because it cannot carry as much cholesterol away from dying cells and arteries to be broken down in the liver,” Shah explains. “A small LDL is more easily incorporated into artery walls forming plaque.”
Exercise and postmenopausal women
Graduate students Sarah Bailey and Adam Gloeckner, mentored by both Mitchell and Shah, examined the effect of a prior bout of aerobic exercise on postprandial endothelial function in postmenopausal women. Endothelial function, a marker of cardiovascular disease, was assessed by Bailey and Andy Kreutzer though flow mediated dilation (brachial artery diameter in response to an increase in blood flow) and blood markers. There are very few such studies involving postmenopausal women.
The researchers found that a bout of exercise did not improve endothelial function or insulin sensitivity in these women. The findings on lipids and lipoproteins from this study by Gloeckner were more exciting and are currently under review by a journal, Shah says.
Keto vs. high-carb
Looking ahead, Shah is eager to return to research work disrupted by the coronavirus pandemic. She, PhD students Kreutzer, Austin Graybeal and Kamiah Moss, MS students Petra Rack and Garrett Augsburger, undergraduates Jorde Trudel, Emma Kate, Megan Conger, and Desiree Tadwilliams, and faculty members Trocchio, Willis, and Castleberry were evaluating the effects of a ketogenic (very low-carbohydrate) diet compared with a high-carbohydrate diet on a number of outcomes in highly trained athletes.
“We were comparing the effects of these two diets on performance and postprandial energy expenditure, lipids and lipoproteins, hormones that control hunger and fullness, glycemic control and sleep quality. Dr. Trocchio along with her MS students Kaitlyn Harrison and Ashlynn Williams were examining the effects of these diets on mood and cognitive function,” she says. “We had just completed six participants before we were told to stop the study because of COVID-19. We had another six participants who would have completed in another few weeks if we had been able to continue. So we lost half our sample size essentially.”
Shah hopes to restart the study once outside participants are allowed back on campus.