Diet and exercise interventions for eating behaviors and weight loss

Over the years, overweight and obese women may have developed maladaptive eating behaviors. These behaviors include binge eating, uncontrolled eating, emotional eating, and restrained eating. Restrained eating, which is considered a complex term, is attributed to restrictive food intake to control weight; however, superfluous eating based on restrictions can cause weight gain. Binge eating behaviors have been associated with higher body mass index (BMI) within the US population. In a recent study, women with obesity were more likely to report binge eating incidents in comparison with women of healthy weight.  In a study with 300 obese primary care patients, half of the patients reported high emotional eating scores and a fourth of the patients had high uncontrolled eating scores; women were more likely than men to exhibit emotional and uncontrolled eating behaviors.  Group based-behavioral weight loss has been reported to reduce the occurrence of binge eating in obese adults. Also, indirect responses of exercise have improved emotional eating.

The most recent studies on maladaptive eating behaviors have reported diverse associations in lifestyle-based weight loss interventions. The various associations could be based on study populations, intervention design, and inconsistencies within measuring tools. The primary objective of the study from Dr. Anne McTiernan’s group in the Public Health Sciences Division were to determine the effects of separate and combined dietary weight loss and exercise interventions on eating behaviors in postmenopausal women. The second objective was to evaluate the baseline eating behaviors on diet, exercise intervention adherence, and weight loss outcomes among postmenopausal women.  The results were published in the International Journal of Behavioral Nutrition and Physical Activity.  

The study design consisted of a post-hoc secondary analysis for a 12-month randomized controlled trial conducted from 2005 to 2009 at Fred Hutch.  The study titled the Nutrition and Exercise in Women (NEW) study used a 4-arm design to compare the effect of three lifestyle-change interventions on body weight and composition: moderate to vigorous intensity aerobic exercise, dietary weight loss, both interventions combined (exercise and diet) compared to no lifestyle change.  The target population consisted of postmenopausal women from the greater Seattle area, aged 50-75 years, who were overweight or obese (BMI ≥ 25 kg/m²) and exercised less than 100 minutes per week at moderate intensity or greater. Asian American women with a BMI ≥ 23 kg/m² were included in the study.  The exclusion criteria consisted of women with diabetes, the use of hormone therapy, history of breast cancer, and the current use of tobacco or drinking, and more than two alcohol drinks per day.

Women were recruited through mass mailing campaigns, media publicity or community outreach.  A total of 439 women participated in the study.  The study participants were randomized using a computerized random assignment: moderate to vigorous intensity aerobic exercise (n= 117), dietary weight loss (n=118), combined diet and exercise (n=117), and no intervention (n=87).  Dr. McTiernan describes the methods of the intervention, “Our weight loss program was delivered by behaviorally-trained nutritionists. Each participant met with the nutritionist alone for 2 – 4 sessions and met weekly with a nutritionist in a group.” The goals for the diet arms of the intervention included: 1200 - 2000 kcal/day based on participants’ baseline weight, less than 30% calories from fat, and 10% weight loss by 6 months.  Individual and group sessions were available to the participants to develop techniques for goal setting, self-monitoring, coping strategies, and problem solving. 

A total of 398 participants completed the questionnaires and physical exam.  Based on the eating behavior scores at baseline, women with obesity had lower restrained eating scores (p=0.04) and higher emotional and binge eating scores (p<.0001) than women with overweight.  Correlations of baseline eating behavior scores and psychosocial factors were examined among participants.  Binge eating, uncontrolled eating, and emotional eating were positively associated with higher perceived stress, anxiety, and depression scores (p<.001).  As shown in Table 1, women randomized to the diet arm of the intervention reported reductions in binge eating (-23.7%, p=0.005), uncontrolled eating (-24.3%, p<0.001), emotional eating (-31.7%, p<0.0001), and an increased in restrained eating (+60.6%, p<0.001).  Women randomized to the combined intervention, diet and exercise, reported less uncontrolled eating (-22.0% p=0.004) and increased restrained eating (+41.1, p<0.001).  Women randomized to the exercise arm of intervention reported no significant changes within the 12-month period, indicating that dietary intervention was more effective at changing maladaptive eating behaviors.

Dr. McTiernan elaborated on the findings of the study, “We found that the dietary weight loss program, which stressed positive behavior changes, helped women modify eating behaviors. We also found that women who had improvements in emotional eating, binge eating, and uncontrolled eating lost more weight than women whose eating behaviors did not improve.” Women who concentrated on goal setting, self-monitoring, coping strategies and problem solving improved their eating behavior scores compared to the controls. This study is consistent with others that report positive changes in women with maladaptive eating behaviors from behavioral weight loss programs. Also, the question of whether this intervention aids long-term for weight loss in women with maladaptive eating behaviors has yet to be answered. For future implications, Dr. McTiernan stated the importance of conducting weight loss and exercise interventions in other populations including diverse race/ ethnic groups of women and men. 

This research was funded in part through the NIH/NCI Cancer Center Support Grant P30 CA015704 and supported by grants from the National Cancer Institute at the National Institutes of Health: R01 CA105204-01A1, NIH R03 CA162482-01 and grants from the Breast Cancer Research Foundation (BCRF-16-106 and BCRF-17-105). 

Fred Hutch/UW Cancer Consortium members Anne McTiernan and Ching-Yun Wang contributed to this research.

Mason C, de Dieu Tapsoba J, Duggan C, Wang CY, Alfano CM, McTiernan A. Eating behaviors and weight loss outcomes in a 12-month randomized trial of diet and/or exercise intervention in postmenopausal women. International Journal of Behavioral Nutrition and Physical Activity. 2019 Dec 1;16(1):113.