Diana Thomas

‌Through research performed at Montclair State, Associate Professor Diana Thomas and her colleagues have proven mathematically that increased exercise does not rev up the metabolism or ensure weight loss; the only way to effectively lose weight is to simply eat less. Now she is seeing the practical results of her equations.

“The question became, ‘Can we really help people lose weight using mathematics?’” the director of the Center for Quantitative Obesity Research at Montclair State says. And the answer, they found, is, “Yes.” The mathematical model, developed in collaboration with a team of researchers and mathematicians, could prove helpful in battling the obesity epidemic in the United States and may even change the way people diet.

Thomas’ research on mathematical modeling of weight has received funding from the National Institutes of Health (NIH) and helped more than 70 study participants lose weight at the Pennington Biomedical Research Center in Baton Rouge, Louisiana. In one collaborative NIH-funded study at Pennington Biomedical, patients who used Thomas’ model lost more than eight percent of their body weight. “When they told me how well it worked, and how it improved patients’ health, that’s what changed everything for me,” Thomas says.

Her energy balance equation calculates how much, or how little, a dieter should eat to lose weight based on such factors as height, weight, age and gender.

Counselors at Pennington Biomedical are then able to adjust diet plans and behavior counseling accordingly and know for certain whether participants are sticking with their diets, says Corby Martin, a researcher at the center.

“Diana’s work is immensely significant,” Martin says. “My research and our studies here are based on Diana’s work and our collaboration with Montclair State University. It serves as a foundation for our clinical trials and makes it easier for patients to follow their diets. ”

Diana Thomas

As participants begin using the calculator (available at montclair.edu/csam/center-quantitativeobesity/ links/), they plot their weight change on easy-to-read graphs that show a “zone” or range that corresponds to the expected weight change according to physiology. If participants closely follow their diet plans, their weight should fall into the zone. The calculator also can help people set realistic weight loss goals. By plugging in a dietary intake goal, they can see the estimated weight changes over time.

It takes only a small adjustment to get back in the zone, and as patients see they’re losing weight by adhering to their diets, they become motivated to stay on track. “Compared to calorie counting, this is much easier,” says Thomas.

Weight loss counselors at Pennington Biomedical agree. “There’s something about being in the zone that motivates them,” says Allison Davis, a counselor at Pennington Biomedical using the model. “Participants really respond. I think it makes them feel more in control. And I love being able to show them their personal graph that shows if they stick to the program this is how much weight they will lose.”

Thomas and researchers at Pennington Biomedical, Duke University, Maastricht University and the Technical University of Lisbon also collaborated on another study that applied the first law of thermodynamics to explain why exercising, while good for you, does little to help you lose weight.

Again, mathematics proved the point. “If the data is not telling you what you think it will, then your hypothesis is wrong. Data doesn’t lie,” says Thomas. “We were trying to understand why people weren’t losing weight if they said they were exercising and eating a certain amount. The data shows that your metabolism doesn’t increase when you exercise. Vigorous exercise makes you hungrier and you tend to eat more.”

Exercise does, however, make people feel and look better. “But if you’re looking at exercise for weight control, forget it,” she says. “If you work out very, very hard, everything is going to be against you for weight loss.”

Montclair State and Pennington Biomedical’s collaboration continues as they work together on a groundbreaking NIH study, applying Thomas’ mathematical equation to pregnant women to help them gain the optimum amount of weight during pregnancy and also to prevent diabetes through weight loss in women who recently had gestational diabetes. The NIH funding for the $3.5 million Pennington Biomedical study aims to improve outcomes for both mother and baby.

Thomas’ passion for this research is rooted in personal experience. While you would never guess it to look at her now, by the end of her first pregnancy 12 years ago, she weighed in at 179 pounds. Then she had to go about losing 70 pounds. Two years later, she began working on her initial studies about fetal and maternal weight gain, and she kept her subsequent pregnancy weight gain to the traditionally prescribed 25 pounds.

“This is very personal for me,” she says. “I’m not the only woman who gained a lot of weight during pregnancy. I care a lot about women’s health and was shocked to find that so many of the widely publicized weight recommendations for pregnant women are outdated and often based on conclusions from studies of men and non-pregnant women.”

The latest collaborative study with Pennington Biomedical will involve more than 300 women, starting at the beginning of their pregnancies and following them through delivery, giving them guidelines for how much to eat and how much weight they should gain in each trimester based on the math.

“We hope to be able to improve the mother and the baby’s health in a way that will have impact in the long run,” Thomas says.

While Thomas originally thought she would be a math professor, using mathematics to fight obesity and improve women’s health has taken her career in a different direction, leading to speaking engagements and media interest. She’s presented at the University of Alabama, George Mason University and Rutgers University, as well as at conferences in New York and China.

Last year, the results of a study she co-authored linking a decrease in workplace physical activity to the obesity epidemic made it into The New York Times, USA Today and Shape magazine.

The online calculator for predicted weight loss also has garnered some attention including another mention in The New York Times, because it is designed so that anyone can plug in their numbers and see what it will take to lose weight. Thomas’s team is also working on an app for a handheld diet adherence calculator. “That way, people can check it anytime, anywhere,” she says. “It eliminates the need for calorie counting.”

Montclair State’s collaboration with Pennington Biomedical allows Thomas’ students to see how the science and math they learn in the classroom have real-world applications.

“We train students in health-related fields to be part of a medical research team,” Thomas says. “That may mean hosting research visitors from around the world, writing grants and papers or directly working with patients.”‌