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. To view publications reflecting our work in each area, click on the numbered links.
- The relationship between dieting, restrained eating, and weight control
- Obesity and the prevention of weight gain and weight regain
- The role of weight suppression and current dieting in eating disorders
- Integrating biology and psychology in eating disorder and obesity research
- Research on "hedonic hunger" and the Power of Food Scale
1. The relationship between dieting, restrained eating and weight control
I have a long-standing interest in the relationship between dieting, restrained eating and body weight. 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, which means that 1) most dieters develop a history of repeatedly losing and regaining weight, and 2) having a history of weight loss dieting actually predicts accelerated weight gain over time (Lowe et al, 2013 (PDF)). On the other hand, a 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)).
2. 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. Over a six month period the intervention produced significant reductions in caloric intake during lunch and a significant reduction in the percentage of calories from fat (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 from the intervention year and one-year follow-up have been collected, and data collection for the second-year followup will be complete in December, 2014. 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 over the past few years. Professor Butryn is principal investigator on this grant and Professor Forman and I are co-investigators.
3. Eating disorders research
Most of our eating disorders research has been conducted in collaboration with the Renfrew Center for eating disorders, where Professor Lowe has 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 masters and dissertation research projects to be completed.
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), Berner et al, 2013 (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 that we hope to examine in the future.
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.
4. 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 and hedonic eating motives 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 aspects of restrained eating combine to produce a predisposition toward weight gain in chronic dieters (Lowe & Kral, 2006 (PDF), Stice et al., 2004, Lowe et al, 2013, (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)).
5. 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 as opposed to removing a 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.