My research involves the study of eating and weight disorders from the perspectives of clinical psychology, nutritional science, and neuroscience. The following describes five general areas in which my research group has been studying these domains.
See recent publications and presentations involving these domains
The relationship between dieting, restrained eating and weight control
I have a long-standing interest in the relationship between dieting and restrained eating, on one hand, and eating and weight regulation, on the other. My work has led to the following conclusions. Though often viewed as interchangeable in the literature, restrained eating and dieting are different constructs associated with different behavioral effects (Lowe, 1993 [PDF], Lowe and Kral, 2006 [PDF], Lowe and Levine, 2005 [PDF]; Lowe and Thomas, 2009 [PDF], Witt et al, 2013 [PDF]). Restrained eating usually reflects an effort to prevent overeating and weight gain, not an effort to lose weight or to become skinny (Chernyak and Lowe, 2010 [PDF], Stice et al., 2007 [PDF]). Dieting, on the other hand, usually reflects an effort to reduce calories to lose weight (Goldstein et al, 2013 [PDF]). Dieters may succeed in losing weight but relatively few succeed in keeping it off. After reviewing the literature on dieting and body mass, I came to the conclusions that 1) repeated dieting does not cause weight gain beyond whatever weight is regained in the process of returning to starting weight (Lowe et al 2015 [pdf]). and 2) a history of dieting is a robust predictor of future weight gain (Lowe et al., 2013 [PDF]) because such a history reflects a pre-existing susceptibility toward accelerated weight gain (Lowe et al 2015 [PDF]). On the other hand, a very small percentage of young women diet too vigorously, lose substantial weight and develop an eating disorder (e.g., Butryn et al., 2006 [PDF]), Lowe et al., 2011 [PDF]). The lab is currently studying the biologicial and psychological characteristics of repeat dieters that make them vulnerable to future weight gain.
Obesity and the prevention of weight gain and weight regain
Hundreds of research studies have found that medically significant weight losses can be achieved by lifestyle change programs. However lost weight starts to be regained once treatment ends. In the past 14 years we have received several NIH grants to study the prevention of weight gain and, after a weight loss, the prevention of weight regain. Our approach to the prevention of weight regain involves a significant departure from the traditional "lifestyle change" approach to weight control (Lowe, 2003). Our first study aimed to improve weight loss maintenance by teaching methods for reducing the energy density (the number of calories per gram of food consumed) of the diet (Lowe et al., Obesity, 2008 [PDF]).
A second grant examined long-term modifications to worksite cafeterias to improve nutritional intake and prevent weight gain among patrons. (Lowe et al., 2010 [PDF]).
A third grant was a 5-year study examining new ways of preventing weight regain following weight loss. Participants were overweight patients referred from primary care practices. This project tested two different nutritional strategies (increasing structured eating via use of meal replacements, and lowering the caloric density of the diet) in order to avoid or minimize weight regain after weight loss. The data from this study showed that a program focusing on making multiple changes to home food environment to reduce the caloric density of the diet was the only one of four treatments that produced maintenance of lost weight at a two-year follow-up (Lowe et al, 2014, [PDF]).
A fourth grant in this category focused on prevention of weight gain in female college freshmen. This study was done in collaboration with Professors Eric Stice and Meghan Butryn. It targeted students vulnerable to weight gain but, surprisingly, participants on average did not gain weight over the two-year course of the study, precluding the possibility of demonstrating a preventive effect. We are currently using the longitudinal data set to identify longitudinal predictors of weight change and eating disorder symptoms.
A fifth grant is a 5-year study that is comparing three treatments aimed at improving the long-term maintenance of weight loss. The main intervention of interest (called “Nutritrol” for the nutritional control of body weight) focuses on modifying foods in participants’ home food environments (Lowe, 2003 [PDF]) so that self-control becomes more feasible and automatic. This project began in April, 2009. Data collection through during treatment and two yearly follow-up assessments has been collected and data analysis is underway.
In 2011 we were awarded a new NIH grant that is comparing a) standard behavioral treatment, b) standard treatment plus an environmentally-focused intervention, and c) both interventions plus an Acceptance and Commitment (ACT) treatment that has been developed by Evan Forman and Meghan Butryn. The project found that weight loss was significantly higher in the ACT-treatment group, and was particularly effective in those with depression, disinhibition and emotional eating (Forman et al, 2013 [PDF]).
Eating disorders research
Most of our eating disorders research has been conducted in collaboration with the Renfrew Center for eating disorders. I have been a research consultant, and a member of their Research and Training Committees, for many years. Renfrew is the largest treatment center for eating disorders in the country and therefore offers the unique ability to collect data on a large number of eating disordered patients in a relatively short time. The data available at Renfrew has created many opportunities for for data collection for masters and dissertation research projects.
We implemented an NIMH R34 project at Renfrew several years ago. This project was designed to test the effects of introducing cognitive-behavioral therapy into one of Renfrew’s intensive outpatient programs. This project taught us a number of “real-world” lessons, as outlined in a paper that described our experience (Lowe, Bunnell, et al., 2011 [PDF])
I have been conducting research investigating the role of both weight suppression (the discrepancy between one’s highest adult body weight and current weight) and current dieting (an ongoing effort to lose, or avoid gaining, weight) in bulimia nervosa for the past 15 years (Butryn et al., 2006 [PDF]; Butryn et al., 2011 [PDF]; Chernyak & Lowe, 2010 [PDF], Gleaves et al., 2000 [PDF]; Herzog et al., 2010 [PDF], Lowe et al., 1996 [PDF]; Lowe et al., 1998 [PDF]; Safer et al., 2004 [PDF]; Lowe et al., 2006 [PDF]; Lowe et al., 2007 [PDF], Lowe et al., 2011 [PDF], Goldstein et al, 2013 [PDF]. We have also examined weight suppression in anorexia nervosa Berner et al, 2013 [PDF]; Witt et al, 2014 [PDF]). My research on weight suppression, dieting and eating disorders has raised questions about the prevailing psychosocial and cognitive-behavioral models of how dieting may initiate and maintain bulimia nervosa. This new model also has significant treatment implications. Adrienne Juarascio, PhD, a research assistant professor in the department, is now studying the treatment implications of this research in a recently funded K-23 award from NIMH.
We are taking the next step toward understanding the role of weight suppression and current dieting in bulimia nervosa with the help of a new NIMH grant that started in the fall of 2012. This grant is examining biological and behavioral correlates of both types of dieting and is a collaborative effort between Drexel and Columbia Universities. An abstract describing the study can be found here, and it is detailed in full in our Current Projects section.
We have also recently been awarded a follow-up grant to further investigate the roles of weight suppression and current dieting in eating disorders. This study will examine fMRI-assessed brain reward and inhibitory areas and weight history variables to predict, cross-sectionally and prospectively, ED psychopathology. Results will support development of novel treatments for these treatment-resistant disorders. For more information, please see the Current Projects section.
Integrating biology and psychology in eating disorder and obesity research
In the past several years I have become increasingly involved in research to understand how biological and psychological factors combine to influence eating disorders and obesity. One such effort has involved differentiating between homeostatic eating motives (i.e., eating for calories) and hedonic eating motives (i.e., eating for pleasure) and describing the implications of this distinction for the wisdom of dieting (Lowe & Butryn, 2007 [PDF]; Lowe & Levine, 2005 [PDF], Witt et al, 2013 [PDF]). A second focus is understanding how behavioral and metabolic predisposition to weight gain and why a history of dieting is a robust predictor of future weight gain how behavioral and metabolic aspects of restrained eating combine to produce a predisposition toward weight gain in chronic dieters (Stice et al., 2004, Lowe et al, 2013, [PDF]; Lowe et al 2015 [PDF]). A third set of studies is examining neurophysiological correlates of both restrained eating and binge eating using fMRI and EEG (Coletta et all, 2009 [PDF]; Ely et al, 2014 [PDF]; Lowe et al., 2009 [PDF]; Ochner et al., 2009 [PDF]; Manasse et al, 2015 [PDF]; Winter 2015 [PDF]; Feig 2015 [PDF]).
Research on "hedonic hunger" and the Power of Food Scale
To better understand the predisposition that may make some people more susceptible to food-related temptations, my research team has developed a measure of the drive to eat for pleasure (i.e., when not in a state of caloric deficit). It is called the Power of Food Scale (PFS). There are a number of existing measures that assess restrained eating or overeating induced by various emotional or social stimuli, but there is no measure of individual differences in the psychological impact of an obesogenic environment. Two papers provide psychometric support for the PFS (Capelleri et al., 2009 [PDF], Lowe et al., 2009 [PDF]) and several others examine its usefulness for understanding eating motivations and weight problems (Forman et al., 2007 [PDF]; Schultes et al., 2010 [PDF], Appelhans et al., 2012 [PDF], Rejeski et al., 2012 [PDF], Witt et al, 2013 [PDF]). We are continuing with research to further test the validity and clinical application of the PFS.