Food Selections of Roux-en-Y Gastric Bypass Patients up to 2.5 Years Postsurgery

Food preferences after bariatric surgery: a review update

Obesity is a serious and global health problem. The multiple complications of obesity reduce quality of life and increase mortality. Bariatric surgery is one of the best treatment options for obesity management. Bariatric surgery helps people reduce their caloric intake by treating the disease of obesity effectively, in part by increasing signaling from the gut to the brain. The most frequent surgical options are Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). There is controversy regarding changes in food preferences and selection after bariatric surgery. In this review, we aim to outline the changes in food intake and selection, clarify the behavior changes in food intake, and assess the potential mechanisms responsible for these changes in patients after bariatric surgery.

One Year Follow-Up of Taste-Related Reward Associations with Weight Loss Suggests a Critical Time to Mitigate Weight Regain Following Bariatric Surgery

Background: Weight regain is a concerning issue in bariatric patients. We previously demonstrated that taste-related reward processing was associated with six-month weight loss outcomes following Roux-en-Y gastric bypass (RYGB) but not vertical sleeve gastrectomy (VSG). Here, we assessed whether these taste factors persisted in predicting weight loss, and weight regain, at one year post-surgery. Methods: Adult women enrolled in a longitudinal study of taste preferences following bariatric surgery completed behavioral and neuroimaging assessments at one year post-surgery. Results: RYGB produced better weight loss relative to VSG, with weight regain and greater weight loss variability observed from six months to one year post-VSG. Changes in liking for high fat at 2 weeks post-surgery from baseline remained a predictor of weight loss in RYGB, but other predictors did not persist. Average liking ratings rebounded to baseline and higher self-reported food cravings and dietary disinhibition correlated with poorer weight loss at one year post-surgery. Conclusion: Initial anatomical and metabolic changes resulting from RYGB that reset neural processing of reward stimuli in the mesolimbic pathway appear to be temporary and may be contingent upon post-operative eating behaviors returning to preoperative obesogenic tendencies. Six months post-surgery may be a critical window for implementing interventions to mitigate weight gain.

Taste-related reward is associated with weight loss following bariatric surgery

BACKGROUNDBariatric surgeries are the most effective treatments for successful and sustained weight loss, but individuals vary in treatment response. Understanding the neurobiological and behavioral mechanisms accounting for this variation could lead to the development of personalized therapeutic approaches and improve treatment outcomes. The primary objectives of this study were to investigate changes in taste preferences and taste-induced brain responses after Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) and to identify potential taste-related predictors of weight loss.METHODSFemales, ages 18 to 55, with a body mass index greater than or equal to 35 kg/m2, and approved for bariatric surgery at the Johns Hopkins Center for Bariatric Surgery were recruited for participation. Demographics, anthropometrics, liking ratings, and neural responses to varying concentrations of sucrose plus fat mixtures were assessed before and after surgery via visual analog scales and functional MRI.RESULTSBariatric surgery produced decreases in liking for sucrose-sweetened mixtures. Greater preference for sucrose-sweetened mixtures before surgery was associated with greater weight loss in RYGB, but not VSG. In the RYGB group only, individuals who showed lower taste-induced activation in the ventral tegmental area (VTA) before surgery and greater changes in taste-induced VTA activation 2 weeks following surgery experienced increased weight loss.CONCLUSIONThe anatomical and/or metabolic changes associated with RYGB may more effectively "reset" the neural processing of reward stimuli, thereby rescuing the blunted activation in the mesolimbic pathway found in patients with obesity. Further, these findings suggest that RYGB may be particularly effective in patients with a preference for sweet foods.FUNDINGNIH K23DK100559 and Dalio Philanthropies.

Comparison of Energy and Food Intake Between Gastric Bypass and Sleeve Gastrectomy: a Meta-analysis and Systematic Review

AbstractObesity is a developed nutritional problem, and today, surgery is one of the approaches to cure it. A good understanding of the variations in food intake will be beneficial for sustaining long-term weight loss post-surgery and for improving nutrition care strategies. The purpose of this review was the comparison of the impact of two methods of gastric bypass (GBP) and sleeve gastrectomy (SG) on dietary intake. Databases of PubMed, Embase, Scopus, Google Scholar, and Web of science were used for the literature search up to June 2018. We concluded the studies that measured mean daily energy intake and the percent of macronutrients from total calorie intake of before and after GBP and SG. A total of 18 studies were finally included in the meta-analysis for the effect of bariatric surgery on food intake. Bariatric surgery significantly decreased energy intake by 1050.04 kcal/day (p < 0.001) compared with the baseline values of energy intake. The pooled effect of bariatric surgery on protein intake was 0.82 g/day (p = 0.004) compared with the baseline values. The pooled analysis found no significant impact of bariatric surgery on carbohydrate intake (WMD = 0.56 g/day; p = 0.40) compared with the baseline values. The pooled estimate of effect for bariatric surgery on fat intake was - 1.34 g/day (p = 0.006). This study demonstrates that bariatric surgery might be effective on energy and fat intake; however, there was no effect on carbohydrate intake.

The effects of bariatric surgery on psychological aspects of eating behaviour and food intake in humans

Bariatric surgery has emerged as an increasingly popular weight loss intervention, with larger and more endurable weight loss compared to pharmacological and behavioural interventions. The degree of weight loss patients experience varies, between individuals, surgeries and over time. An explanation as to why differing weight loss trajectories exist post-surgery could be due to the complex interplay of individual differences in relation to eating behaviours and appetite. Thus the aim of this narrative review is to explore literature between 2008 and 2018, to assess the impact of impact of bariatric surgery on food selection and nutrient status, on eating behaviour traits and on disturbed and disordered eating behaviour, to determine their impact of weight loss success and weight loss trajectories. Immediately post-surgery, up until 1-2 years post-surgery, there is a reliance upon the surgery's alteration of the gastrointestinal tract to control food intake and subsequently lose weight. Energy intake is reduced, dietary adherence is higher, supplement intake is higher, appetite ratings are lower, there is a reduction in psychopathology, and an increase in wellbeing. After this point, patients become more susceptible to weight regain, as this is the point where passive observation of the weight reducing action of surgery, moves into more cognitive effort, on the part of the individual, to control energy intake. There are various factors which influence an individual's ability to successfully regulate their energy intake post-surgery, such as their level of Disinhibition, Restraint, Hunger, Emotional Eating, Uncontrolled Eating, psychopathology and wellbeing. The need for continued psychological and nutritional support post-surgery is necessary to reduce weight regain susceptibility.

Taste Changes after Bariatric Surgery: a Systematic Review

BACKGROUND

Alterations in taste perception and preferences may contribute to dietary changes and subsequent weight loss following bariatric surgery.

METHODS

A systematic search was performed to identify all articles investigating gustation, olfaction, and sensory perception in both animal and human studies following bariatric procedures.

RESULTS

Two hundred fifty-five articles were identified after database searches, bibliography inclusions and deduplication. Sixty-one articles were included. These articles provide evidence supporting changes in taste perception and hedonic taste following bariatric procedures. Taste sensitivity to sweet and fatty stimuli appears to increase post-operatively. Additionally, patients also have a reduced hedonic response to these stimuli.

CONCLUSIONS

Available evidence suggests that there is a change in taste perception following bariatric procedures, which may contribute to long-term maintenance of weight loss following surgery.

Taste and odor preferences following Roux-en-Y surgery in humans

It is well established that bariatric surgery, the most effective method to achieve long-term weight loss in obese subjects, reverses enhanced preference and intake of sweet/fatty foods. Although taste and odor preference changes following bariatric surgery have been previously described, their time course and relationship to weight loss remains an issue. The aim of this study was to determine the relationship between taste and odor preference changes and successful weight loss following bariatric surgery. A cross-sectional study was performed on 195 human subjects with body mass index (BMI) above 30 (at least class I obesity), who were scheduled to receive (n = 54) or had previously received (n = 141) Roux-en-Y gastric bypass (RYGB). A Self-Assessment Manikin test was used to measure each participant’s affective reaction (ranging from pleasure to displeasure) to a variety of food-related and odor-related pictures. Results confirmed earlier reports about changes in sweet/fatty foods preference after surgery and revealed a shift in preference toward less calorie-dense foods. Relatedly, endorsements of “favorite” foods were mostly sweet/fatty foods in subjects awaiting surgery but were shifted toward more healthy choices, particularly vegetables, in subjects post-RYGB surgery. However, food preference ratings trended toward pre-surgical levels as the time since surgery increased. Answers to open-ended questions about why their diet changed post-surgery revealed that changes in cravings, rather than changes in taste per se, were the major factor. Surprisingly, patients rating a coffee taste as more pleasing after surgery had a lower post-surgical BMI. No associations of odors with change in BMI were apparent. Results showed that following bariatric surgery taste preferences are significantly altered and that these changes correlate with lowered BMI. However, these changes fade as time since surgery lengthens. These results may suggest diagnostic criteria to identify people at risk for less than optimal changes in BMI following bariatric surgery.

Proceedings of the 2015 ASPEN Research Workshop-Taste Signaling

This article summarizes research findings from 6 experts in the field of taste and feeding that were presented at the 2015 American Society for Parenteral and Enteral Nutrition Research Workshop. The theme was focused on the interaction of taste signals with those of a postingestive origin and how this contributes to regulation of food intake through both physiological and learning processes. Gastric bypass results in exceptional loss of fat mass and increases in circulating levels of key gut peptides, some of which are also expressed along with their cognate receptors in taste buds. Changes in taste preference and food selection in both bariatric surgery patients and rodent models have been reported. Accordingly, the effects of this surgery on taste-related behavior were examined. The conservation of receptor and peptide signaling mechanisms in gustatory and extraoral tissues was discussed in the context of taste responsiveness and the regulation of metabolism. New findings detailing the features of neural circuits between the caudal nucleus of the solitary tract (NST), receiving visceral input from the vagus nerve, and the rostral NST, receiving taste input, were discussed, as was how early life experience with taste stimuli and learned associations between flavor and postoral consequences of nutrients can exert potent and long-lasting effects on feeding.

Roux-en-Y gastric bypass in rats progressively decreases the proportion of fat calories selected from a palatable cafeteria diet

Roux-en-Y gastric bypass surgery (RYGB) decreases caloric intake in both human patients and rodent models. In long-term intake tests, rats decrease their preference for fat and/or sugar after RYGB, and patients may have similar changes in food selection. Here we evaluated the impact of RYGB on intake during a "cafeteria"-style presentation of foods to assess if rats would lower the percentage of calories taken from fat and/or sugar after RYGB in a more complex dietary context. Male Sprague-Dawley rats that underwent either RYGB or sham surgery (Sham) were presurgically and postsurgically given 8-days free access to four semisolid foods representative of different fat and sugar levels along with standard chow and water. Compared with Sham rats, RYGB rats took proportionally fewer calories from fat and more calories from carbohydrates; the latter was not attributable to an increase in sugar intake. The proportion of calories taken from protein after RYGB also increased slightly. Importantly, these postsurgical macronutrient caloric intake changes in the RYGB rats were progressive, making it unlikely that the surgery had an immediate impact on the hedonic evaluation of the foods and strongly suggesting that learning is influencing the food choices. Indeed, despite these dietary shifts, RYGB, as well as Sham, rats continued to select the majority of their calories from the high-fat/high-sugar option. Apparently after RYGB, rats can progressively regulate their intake and selection of complex foods to achieve a seemingly healthier macronutrient dietary composition.

Mechanism Underlying the Weight Loss and Complications of Roux-en-Y Gastric Bypass. Review

Various bariatric surgical procedures are effective at improving health in patients with obesity associated co-morbidities, but the aim of this review is to specifically describe the mechanisms through which Roux-en-Y gastric bypass (RYGB) surgery enables weight loss for obese patients using observations from both human and animal studies. Perhaps most but not all clinicians would agree that the beneficial effects outweigh the harm of RYGB; however, the mechanisms for both the beneficial and deleterious (for example postprandial hypoglycaemia, vitamin deficiency and bone loss) effects are ill understood. The exaggerated release of the satiety gut hormones, such as GLP-1 and PYY, with their central and peripheral effects on food intake has given new insight into the physiological changes that happen after surgery. The initial enthusiasm after the discovery of the role of the gut hormones following RYGB may need to be tempered as the magnitude of the effects of these hormonal responses on weight loss may have been overestimated. The physiological changes after RYGB are unlikely to be due to a single hormone, or single mechanism, but most likely involve complex gut-brain signalling. Understanding the mechanisms involved with the beneficial and deleterious effects of RYGB will speed up the development of effective, cheaper and safer surgical and non-surgical treatments for obesity.

Changes in eating behaviour and food choices in families where the mother undergoes gastric bypass surgery for obesity

BACKGROUND/OBJECTIVES

There is a lack of research exploring the effects of Roux-en-Y gastric bypass (RYGB) surgery on the patient's family's eating behaviour and food choices. The aim of the current study was to investigate changes in partners' and children's eating behaviour and food choices following maternal RYGB.

SUBJECTS/METHODS

Sixty-nine women and their families were recruited from RYGB waiting lists at five Swedish surgical clinics. Data were collected during home visits 3 months before and 9 months after RYGB. Anthropometrical measures were taken, the adults completed the Three-Factor Eating Questionnaire and the children completed the Children's Eating Attitudes Test (ChEAT). All participants also completed a short food frequency questionnaire.

RESULTS

Changes in scores were analysed using paired t-tests for unadjusted estimates or linear regression models with robust variance (General Estimating Equations) in order to enable age- and sex-adjusted estimates for the children. There were no meaningful differences in the partners' eating behaviour or food choices. The boys, but not the girls, improved their ChEAT scores, as did the overweight/obese children in comparison with the normal-weight children. The boys, unlike the girls, also decreased their intake of soft drinks, as did the normal-weight children when compared with the overweight/obese children.

CONCLUSIONS

No clear-cut changes were found in partners' eating behaviour and food choices. Eating attitudes and soft drinks intake were improved among boys but not among girls. Differing modelling behaviour may partially explain these findings, but available data did not allow us to understand the underlying mechanisms.

Dietary changes in obese patients undergoing gastric bypass or lifestyle intervention: a clinical trial

We compared changes in the dietary patterns of morbidly obese patients undergoing either laparoscopic gastric bypass surgery or a comprehensive lifestyle intervention programme. The present 1-year non-randomised controlled trial included fifty-four patients in the lifestyle group and seventy-two in the surgery group. Dietary intake was assessed by a validated FFQ. ANCOVA was used to adjust for between-group differences in sex, age, baseline BMI and baseline values of the dependent variables. Intakes of food groups and nutrients did not differ significantly between the intervention groups at baseline. At 1-year follow-up, the lifestyle group had a significantly higher daily intake of fruits and vegetables (561 (sd 198) v. 441 (sd 213) g, P= 0·002), whole grains (63 (sd 24) v. 49 (sd 16) g, P< 0·001) and fibre (28 (sd 6) v. 22 (sd 6) g, P< 0·001) than the surgery group and a lower percentage of total energy intake of saturated fat (12 (sd 3) v. 14 (sd 3) %, P< 0·001). The intake of red meat declined significantly within both groups, vegetables and fish intake were reduced significantly in the surgery group and added sugar was reduced significantly in the lifestyle group. The lifestyle patients improved their dietary patterns significantly (compared with the surgery group), increasing their intake of vegetables, whole grains and fibre and reducing their percentage intake of saturated fat (ANCOVA, all P< 0·001). In conclusion, lifestyle intervention was associated with more favourable dietary 1-year changes than gastric bypass surgery in morbidly obese patients, as measured by intake of vegetables, whole grains, fibre and saturated fat.

Food selection and taste changes in humans after Roux-en-Y gastric bypass surgery: a direct-measures approach

It has been suggested that the weight loss seen in individuals who receive Roux-en-Y gastric bypass surgery may be due, at least in part, to changes in patient food selection, and that this change may stem from effects of the operation on the sense of taste. In this review, we evaluate the literature examining postoperative changes in food intake and food choice. While some evidence suggests that gastric bypass leads to altered food selection and taste perceptions, a clear picture regarding these changes remains to be elucidated and is blurred by inconsistencies, which may be rooted in the diverse subject pools within and between studies as well as in the indirect measures used to assess ingestive behavior. We argue that complementing current assessment tools with more direct measures of intake, food selection, and taste-related behavior might help provide some clarity and also facilitate translation between findings from animal models, in which similar measures are available, and clinical research.

Changes in eating behaviour and meal pattern following Roux-en-Y gastric bypass

BACKGROUND

Little is known about eating behaviour and meal pattern subsequent to Roux-en-Y gastric bypass (RYGB), knowledge important for the nutritional care process. The objective of the study was to obtain basic information of how meal size, eating rate, meal frequency and eating behaviour change upon the RYGB surgery.

MATERIALS AND METHODS

Voluntary chosen meal size and eating rate were measured in a longitudinal, within subject, cohort study of 43 patients, 31 women and 12 men, age 42.6 (s.d. 9.7) years, body mass index (BMI) 44.5 (4.9) kg m(-2). Thirty-one non-obese subjects, 37.8 (13.6) years, BMI 23.7 (2.7) kg m(-2) served as a reference group. All subjects completed a meal pattern questionnaire and the Three-Factor Eating Questionnaire (TFEQ-R21).

RESULTS

Six weeks postoperatively meal size was 42% of the preoperative meal size, (P<0.001). After 1 and 2 years, meal size increased but was still lower than preoperative size 57% (P<0.001) and 66% (P<0.001), respectively. Mean meal duration was constant before and after surgery. Mean eating rate measured as amount consumed food per minute was 45% of preoperative eating rate 6 weeks postoperatively (P<0.001). After 1 and 2 years, eating rate increased to 65% (P<0.001) and 72% (P<0.001), respectively, of preoperative rate. Number of meals per day increased from 4.9 (95% confidence interval, 4.4,5.4) preoperatively to 6 weeks: 5.2 (4.9,5.6), (not significant), 1 year 5.8 (5.5,6.1), (P=0.003), and 2 years 5.4 (5.1,5.7), (not significant). Emotional and uncontrolled eating were significantly decreased postoperatively, (both P<0.001 at all-time points), while cognitive restraint was only transiently increased 6 weeks postoperatively (P=0.011).

CONCLUSIONS

Subsequent to RYGB, patients display markedly changed eating behaviour and meal patterns, which may lead to sustained weight loss.