Binge eating and satiety in bulimia nervosa and binge eating disorder: effects of macronutrient intake

Eating disorders, disordered eating, and body image research in New Zealand: a scoping review

BACKGROUND

The prevention and treatment of eating disorders relies on an extensive body of research that includes various foci and methodologies. This scoping review identified relevant studies of eating disorders, body image, and disordered eating with New Zealand samples; charted the methodologies, sample characteristics, and findings reported; and identified several gaps that should be addressed by further research.

METHODS

Using scoping review methodology, two databases were searched for studies examining eating disorders, disordered eating, or body image with New Zealand samples. Snowball methods were further used to identify additional relevant articles that did not appear in initial searches. Two independent reviewers screened the titles and abstracts of 473 records. Full text assessment of the remaining 251 records resulted in 148 peer-reviewed articles being identified as eligible for the final review. A search of institutional databases yielded 106 Masters and Doctoral theses for assessment, with a total of 47 theses being identified as eligible for the final review. The included studies were classified by methodology, and the extracted information included the study foci, data collected, sample size, demographic information, and key findings.

RESULTS

The eligible studies examined a variety of eating disorder categories including binge-eating disorder, bulimia nervosa, and anorexia nervosa, in addition to disordered eating behaviours and body image in nonclinical or community samples. Methodologies included treatment trials, secondary analysis of existing datasets, non-treatment experimental interventions, cross-sectional observation, case-control studies, qualitative and mixed-methods studies, and case studies or series. Across all of the studies, questionnaire and interview data were most commonly utilised. A wide range of sample sizes were evident, and studies often reported all-female or mostly-female participants, with minimal inclusion of males and gender minorities. There was also an underrepresentation of minority ethnicities in many studies, highlighting the need for future research to increase diversity within samples.

CONCLUSION

This study provides a comprehensive and detailed overview of research into eating disorders and body image in New Zealand, while highlighting important considerations for both local and international research.

Macronutrient intake: Hormonal controls, pathological states, and methodological considerations

A plethora of studies to date has examined the roles of feeding-related peptides in the control of food intake. However, the influence of these peptides on the intake of particular macronutrient constituents of food - carbohydrate, fat, and protein - has not been as extensively addressed in the literature. Here, the roles of several feeding-related peptides in controlling macronutrient intake are reviewed. Next, the relationship between macronutrient intake and diseases including diabetes mellitus, obesity, and eating disorders are examined. Finally, some key considerations in macronutrient intake research are discussed. We hope that this review will shed light onto this underappreciated topic in ingestive behavior research and will help to guide further scientific investigation in this area.

Mindful eating, intuitive eating, and the loss of control over eating

BACKGROUND

The loss of control over eating (LOCE) is frequently cited as a core process of eating disturbances. In contrast, mindful eating and intuitive eating have been identified as adaptive styles of eating and have been associated with positive psychological constructs. Therefore, the present study aimed to investigate whether mindful or intuitive eating are potential protective factors for the loss of control over eating.

METHODS

1155 participants (64.2 % female) were recruited from a large university. Participants were administered select subscales of the Intuitive Eating Scale - 2nd edition (IES-2) and Mindful Eating Questionnaire (MEQ), and the brief Loss of Control over Eating Scale (LOCES-B).

RESULTS

Controlling for BMI and age, intuitive and mindful eating were significantly associated with LOCE, F (8,966) = 114.78, p < .001, R² = 0.49. Both IES-2 subscales were negatively associated with LOCE: 1) eating for physical rather than emotional reasons and 2) reliance on hunger and satiety cues, p < .001. One MEQ subscale was negatively associated with LOCE: disinhibition, p < .001. The MEQ subscales assessing awareness and external cues were not significantly associated with LOCE.

CONCLUSIONS

Results suggest that while some forms of mindful eating and intuitive eating are potential protective factors, others may be less relevant to LOCE. These findings have implications for treatment, as they suggest intuitive eating may counteract the loss of control over eating. The findings also provide evidence for convergent validity of the LOCES by clarifying positive constructs that may protect against the development of this core eating pathology.

Interaction of Protein Preloads and Physical Activity on Intake of an Ultra-Processed, High Sugar/High Fat Food/Low Protein Food

“Loss of control, LOC” eating is a major contributor to the development of obesity. Dietary protein is known to promote satiety, but little attention has been paid to the ability of protein, consumed in close proximity to snacking (20 min), to reduce the intake of ultra-processed, low-protein snack foods. We hypothesized that a high-protein preload (HP, 8 g of protein) consumed in close proximity to eating an ultra-processed snack food would reduce intake of the snack food as compared to a low-protein preload (LP, 1.2 g of protein). Two laboratory test meals were conducted, and the intake of ice cream (1.99 kcal/gram) after consuming dairy-based liquid preloads was measured. Habitual physical activity, a potential modulator of satiety, was assessed by a self-reporting questionnaire. Thirty (responders) out of 50 participants reduced their intake of ice cream after the HP preload, with a significant difference in intake observed between the responders and non-responders (−30 ± 25 and 18 ± 18 g, F (1, 49) = 54.36, p < 0.001 for responders and non-responders, respectively). Our data demonstrate that protein consumed in close proximity to ultra-processed snack food can reduce caloric intake by ~60 kcal, which could potentially reduce body weight by at least 5 pounds per year.

A review of treatment manuals for adults with an eating disorder: nutrition content and consistency with current dietetic evidence

PURPOSE

This study aimed to summarise the nutrition and food-related content of treatment manuals for adults with eating disorders (EDs) and assess the degree to which this information conforms with current guidelines and literature.

METHODS

Treatment manuals for adults with an ED were identified by conducting an online search of Internet book dealer Amazon and University of Sydney library catalogue as per methods used in previous reviews of self-help patient resources. The nutrition and food-related content of these manuals was extracted and reviewed independently by two reviewers using a criteria based on current best evidence to date regarding dietetic treatment for EDs.

RESULTS

Twenty-two manuals met inclusion criteria, 20 (91%) of which contained some degree of nutrition and food-related content. Two manuals (9%) included content written by a dietitian, six (27%) included citation of dietetic literature to support the recommendations made and eight (36%) recommended a dietitian be consulted as part of a multidisciplinary approach to treatment. Thirteen manuals (60%) contained nutrition and food-related information not substantiated by current evidence.

CONCLUSION

It is common for treatment manuals for EDs to contain nutrition and food-related content. However, most of the authors of the 22 manuals identified did not appear to collaborate with a dietitian in writing this content or cite peer-reviewed literature to substantiate dietary advice given. Consistent with current clinical practice guidelines, greater collaboration between dietitians and clinicians is required to develop, evaluate and disseminate evidence-based approaches to dietetic management.

LEVEL OF EVIDENCE

Level V, narrative review.

Binge abstinence is associated with reduced energy intake after treatment in patients with binge eating disorder and obesity

OBJECTIVE

Binge eating disorder (BED) is strongly associated with obesity and related medical and psychiatric morbidities. Cognitive behavioral therapy (CBT) has consistently been shown to reduce binge eating frequency and improve psychological functioning, as well as to produce abstinence rates of roughly 50%. This study examined the relationship between binge abstinence and dietary and psychological outcomes after CBT for BED.

METHODS

Fifty adult patients with BED received 6-month treatments using a combination of CBT and dietary counseling. Trained interviewers conducted two 24-hour dietary recall interviews on randomly selected days at baseline and at 6 months.

RESULTS

Participants had significant reductions in energy, macronutrient, and sugar intake and an increase in fruit intake. They reported significant reductions in BMI and binge eating frequency (from mean = 14.24 to mean = 1.90 binge eating episodes during the previous 28 days), as well as improvements in psychological functioning. Those who became binge abstinent reported eating roughly 400 fewer calories per day and experienced greater improvements in psychological functioning than those who did not.

CONCLUSIONS

Findings from this study suggest that individuals who achieve complete cessation from binge eating have significantly improved dietary and psychological outcomes that could potentially improve weight status, compared with those who continue to binge eat post-treatment.

Mice that gorged during dietary restriction increased foraging related behaviors and differed in their macronutrient preference when released from restriction

Caloric restriction (CR) can trigger gorging behavior. We examined macronutrient choice and behavior in mice that gorged during restriction compared to restricted non-gorgers and controls. Fifty MF1 male mice were restricted to 75% of ad-libitum food intake (FI), while ten controls were fed ad-lib. Body mass (BM) and FI were measured two and 24-h after food inclusion over 14-days. ‘Gorging’ mice were defined as those which ate over 25% of their daily FI in 2-h. The top 11 gorgers and the lowest 9 gorgers, along with 10 controls, had their behavior analysed during restriction, and were then provided with an unrestricted food choice, consisting of three diets that were high in fat, protein or carbohydrate. During restriction gorgers ate on average 51% of their daily FI in the 2-h following food introduction while the non-gorgers ate only 16%. Gorgers lost significantly more BM than non-gorgers possibly due to an increased physical activity linked to anticipation of daily food provision. Controls and non-gorgers spent most of their time sleeping. After restriction, both gorgers and non-gorgers were hyperphagic until their lost weight was regained. All 3 groups favoured high fat food. Gorgers and non-gorgers had a significantly greater high carbohydrate diet intake than controls, and gorgers also had a significantly greater high protein diet intake than non-gorgers and controls. On unrestricted food, they did not continue to gorge, although they still had a significantly greater 2-h FI than the other groups. Elevated protein intake may play an important role in the recovery of the lost lean tissue of gorgers after restriction.

Food choice in disorders of eating behavior: correlations with the psychopathological aspects of the diseases

Eating disorders (ED) are characterized by alterations in food choice and in the quantity and quality of nutrient intake. In a population of 124 female patients with ED (anorexia nervosa restricting subtype [AN-R, n=37]; AN bingeing-purging subtype [AN-BP, n=18]; bulimia nervosa purging subtype [BN-P, n=40]; and binge eating disorder [BED, n=29]) and healthy age-matched controls ([C], n=20) we compared food choice and macronutrient intake with psychopathologic symptoms of the disorders. Data were collected from the probands' 7-day food diaries and the scores from two assessment scales (Eating Disorder Inventory-2 [EDI-2] and Temperament and Character Inventory-revised [TCI-R]) that measure symptom domains, dimensions of personality and character dimensions, respectively. Multiple regression analysis was applied to the nutritional data and scale scores. When compared to the values for the control group, intake of animal proteins (grams) was significantly lower for all patient groups, intake of lactoproteins was lower for the AN-R and AN-BP than BN-P and BED groups, intake of vegetal proteins was higher for the AN-R, AN-BP, BN-P and BED groups, intake of dietary fats was lower for the AN-R and AN-BP subtype groups, and intake of total carbohydrates and oligosaccharides was lower for the AN-R and AN-BP groups, and oligosaccharides also for the BED, when calculated in grams but not when expressed in percent. When studied as percent values animal proteins were lower in patients than in controls, lactoprotein in BN-P and BED, vegetal proteins higher in all the patients, fat lower in AN-R and AN-BP, while carbohydrates did not differ between patients and controls. Significant correlations emerged between food choice and TCI-R and EDI-2 scale scores. Food choice in ED might depend on alterations in neurotransmitter peptides, neuropeptides, and peripheral peptides, which regulate and are regulated by macronutrient intake and underlie psychological and temperamental alterations.

A note on eating disorders and appetite and satiety in the orthodox Jewish meal

The relationship between religion and eating concerns is receiving increasing empirical attention; and because religion seems to be important to many women with eating concerns, there is an interest in investigating the role religion plays and ways that religion might be employed therapeutically. Research has indicated that women who feel loved and accepted by God are buffered from eating disorder risk factors. An aspect of religiosity that is unique to Judaism is Halakhah, the system of Jewish Law and Ethics which informs the life of a religiously observant orthodox Jew. In this note, we briefly describe how Halakhah approaches the issues of appetite and satiety in eating meals. These might well contribute to the protective influence regarding tendencies for eating disorders in a person whose culture demands an awareness of and commitment to halakhic norms. Some of the most significant characteristics of disordered eating-lack of appetite, disturbed satiated response, withdrawal from community and decreased spirituality-correlate inversely with the halakhic requirements of eating a meal. We suggest that future studies of orthodox Jewish women measuring eating-order symptomatology and its correlation with religiosity might focus not only on well-known indicators of halakhic adherence such as kashrut and Sabbath observance, but also on the specifics of how their kosher meals are eaten, including ritually washing one's hands before eating, saying the appropriate blessing before and after eating, eating the required two meals on the Sabbath, and fully participating in the Passover Seder meal.

Regulating satiety in bulimia nervosa: the role of cholecystokinin

PURPOSE

Individuals with bulimia nervosa (BN) report altered perceptions in hunger, fullness, and satiety. This article reviews the role of cholecystokinin (CCK), a satiety-producing hormone, in the regulation of binge eating in those who suffer from BN.

CONCLUSION

Studies have shown that CCK is decreased in individuals with BN when compared with healthy controls. Decreased CCK functioning may contribute to impaired satiety and thus binge eating in this patient population. Depending on the macronutrient composition of food choices, CCK release can be differentially influenced. For instance, protein is a potent stimulator of a CCK response. Eating more protein-rich meals increases the release of CCK, increasing satiety and ending a meal.

PRACTICE IMPLICATIONS

Knowledge of CCK functioning and the utility of manipulating the macronutrient composition of meals may inform standard behavioral treatment strategies for those who suffer from BN.

How do eating disorder patients eat after treatment? Dietary habits and eating behaviour three years after entering treatment

OBJECTIVE

Improvements in psychological symptoms and weight have often been demonstrated following eating disorder (ED) treatment, but it is not clear to what extent eating behaviour itself is normalised. This cross-sectional study aimed to investigate dietary habits and eating behaviour in ED patients three years after entering treatment.

METHOD

ED patients (N=70) were divided into those who had recovered (N=36), and those who still suffered from bulimic (N=18) or anorexic (N=16) psychopathology. Patients were compared to a female normal control group of similar age (N=61), and assessments were made on a dietary questionnaire, as well as the BDI, EDI-2, SASB and SCL-90.

RESULTS

With some notable exceptions eating patterns in recovered patients resembled those of controls. Dieting was most evident in recovered and current bulimic patients, while restrictive eating and vegetarianism was found in recovered or current anorexic patients. A majority of the patients with ongoing EDs avoided fatty foods.

DISCUSSION

Risk behaviours such as restrictive eating, dieting and food avoidance, may have an important impact on relapse rates, and it may therefore be imperative to continue to monitor eating behaviour in ED patients following treatment termination to ensure better long-term outcome.

Energy density effects on food intake, appetite ratings, and loss of control in women with binge eating disorder and weight-matched controls

Individuals with binge eating disorder have increased gastric capacity and may require excessive food intake and increased volume in the stomach to produce satiation. The present study examined whether lower energy density (ED) meals lead to lower energy intake more than higher-ED meals in women with binge eating disorder (BED) and weight-matched controls. Women with BED (n=15) and healthy weight-matched controls (n=15) were instructed to consume as much as they wished during two test meals on non-consecutive days. Participants were served two hedonically similar versions of a pasta salad (19% protein, 50% carbohydrate, 31% fat): low-ED (1.0 kcal/g) and high-ED (1.6 kcal/g), and food intake and appetite ratings were assessed. Energy intake was significantly lower in the low-ED condition than in the high-ED condition across all participants. BED participants were more likely to report greater prospective consumption, desire for dessert, loss of control over eating, and less enjoyment after meals. Decreasing the energy density of food consumed may help target disturbances in satiation in women with frequent binge eating.

Loss of control over eating reflects eating disturbances and general psychopathology

This study examined the clinical significance of the loss of control over eating as a key component of eating disorders. It investigated the association of eating-related psychopathology and general psychopathology with objective bulimic episodes (OBEs; experiencing a loss of control while consuming large amounts of food) and subjective bulimic episodes (SBEs; experiencing a loss of control while consuming small/moderate amounts). A community sample of 81 women with a range of disordered eating was recruited: binge-eating disorder, bulimia nervosa, subclinical eating disturbances, or no eating disorders. They were interviewed using the Eating Disorder Examination and completed measures of eating-related and general psychopathology. Both OBE and SBE frequencies correlated significantly with measures of eating-related and general psychopathology, and no significant differences were found between the magnitudes of the correlations with either binge episode type. SBE frequency significantly and independently predicted global eating disorder psychopathology. The loss of control over eating, without consuming large amounts of food, was as closely associated with specific eating disorder psychopathology and general mental health as were traditionally defined OBEs. SBEs may be an important target of treatment and should be considered for future diagnostic classifications of eating disorders.