Food Reward after Bariatric Surgery and Weight Loss Outcomes: An Exploratory Study

Changes in food preferences after bariatric surgery may alter its effectiveness as a treatment for obesity. We aimed to compare food reward for a comprehensive variety of food categories between patients who received a sleeve gastrectomy (SG) or a Roux-en-Y gastric bypass (RYGB) and to explore whether food reward differs according to weight loss. In this cross-sectional exploratory study, food reward was assessed using the Leeds Food Preference Questionnaire (LFPQ) in patients at 6, 12, or 24 months after SG or RYGB. We assessed the liking and wanting of 11 food categories. Comparisons were done regarding the type of surgery and total weight loss (TWL; based on tertile distribution). Fifty-six patients (30 SG and 26 RYGB) were included (women: 70%; age: 44.0 (11.1) y). Regarding the type of surgery, scores were not significantly different between SG and RYGB, except for ‘non-dairy products—without color’ explicit liking (p = 0.04). Regarding TWL outcomes, explicit liking, explicit wanting, and implicit wanting, scores were significantly higher for good responders than low responders for ‘No meat—High fat’ (post-hoc corrected p-value: 0.04, 0.03, and 0.04, respectively). Together, our results failed to identify major differences in liking and wanting between the types of surgery and tended to indicate that higher weight loss might be related to a higher reward for high protein-content food. Rather focus only on palatable foods, future studies should also consider a broader range of food items, including protein reward.     

The Tryptophan/Kynurenine Pathway: A Novel Cross-Talk between Nutritional Obesity,Bariatric Surgery and Taste of Fat

Diet-induced obesity (DIO) reduces the orosensory perception of lipids in rodents and in some humans. Although bariatric surgery partially corrects this alteration, underlying mechanisms remain poorly understood. To explore whether metabolic changes might explain this fat taste disturbance, plasma metabolome analyses, two-bottle choice tests and fungiform papillae (Fun) counting were performed in vertical sleeve gastrectomized (VSG) mice and sham-operated controls. An exploratory clinic study was also carried out in adult patients undergone a VSG. In mice, we found that (i) the VSG reduces both the plasma neurotoxic signature due to the tryptophan/kynurenine (Trp/Kyn) pathway overactivation and the failure of fat preference found in sham-operated DIO mice, (ii) the activity of Trp/Kyn pathway is negatively correlated to the density of Fun, and (iii) the pharmacological inhibition of the Kyn synthesis mimics in non-operated DIO mice the positive effects of VSG (i.e., decrease of Kyn synthesis, increase of Fun number, improvement of the fat taste perception). In humans, a reduction of the plasma Kyn level is only found in patients displaying a post-surgery improvement of their fat taste sensitivity. Altogether these data provide a plausible metabolic explanation to the degradation of the orosensory lipid perception observed in obesity.     

Factors Associated with Nutritional Deficiency Biomarkers in Candidates for Bariatric Surgery: A Cross-Sectional Study in a Peruvian High-Resolution Clinic

Previous studies have described multiple nutritional deficiencies after bariatric surgery (BS). However, few studies have evaluated these deficiencies prior to BS, specifically in Latin America. This study aimed to determine the factors associated with nutritional deficiency biomarkers in candidates for BS in Peru. We included adults of both sexes, aged 18 to 59 years, admitted to a Peruvian clinic with a body mass index (BMI) ≥30 kg/m²; they were candidates for BS from 2017 to 2020. We considered the serum levels of hemoglobin and albumin (in tertiles) as the nutritional deficiency biomarkers. In order to assess the associated factors, we calculated crude (cPR) and adjusted prevalence ratios (aPR) with their respective 95% confidence intervals (95%CI). We analyzed 255 patients: 63.1% were males, with a mean age of 37.1 ± 10.3 years and mean hemoglobin and albumin values of 14.0 ± 1.5 g/dL and 4.6 ± 0.4 g/dL, respectively. We found that males (aPR = 1.86; 95%CI: 1.26–2.73; p = 0.002), participants between 30 and 49 (aPR = 2.02; 95%CI: 1.24–3.28; p = 0.004) or 50 years or more (aPR = 2.42; 95%CI: 1.35–4.35; p = 0.003), participants with a BMI ≥40 kg/m² (aPR = 1.68; 95%CI: 1.09–2.60; p = 0.018), participants with impaired high-density lipoprotein levels (aPR = 1.43; 95%CI: 1.01–2.05; p = 0.049) and individuals in the high tertile of C-reactive protein (aPR = 6.94; 95%CI: 3.37–14.32; p < 0.003) had a higher probability of being in the lower tertile of albumin. In addition, we found that the male sex (aPR = 6.94; 95%CI: 3.37–14.32; p < 0.001) and elevated cholesterol levels (aPR = 0.71; 95%CI: 0.52–0.97; p = 0.034) were associated with the lowest hemoglobin tertile. In our setting, nutritional deficiency biomarkers were associated with sociodemographic, anthropometric and laboratory markers. The pre-bariatric surgery correction of nutritional deficiencies is essential, and can prevent major complications after surgery.     

Evaluation of Dietary Assessment Tools Used in Bariatric Population

Severe obesity is associated with major health issues and bariatric surgery is still the only treatment to offer significant and durable weight loss. Assessment of dietary intakes is an important component of the bariatric surgery process. Objective: To document the dietary assessment tools that have been used with patients targeted for bariatric surgery and patients who had bariatric surgery and explore the extent to which these tools have been validated. Methods: A literature search was conducted to identify studies that used a dietary assessment tool with patients targeted for bariatric surgery or who had bariatric surgery. Results: 108 studies were included. Among all studies included, 27 used a dietary assessment tool that had been validated either as part of the study per se (n = 11) or in a previous study (n = 16). Every tool validated per se in the cited studies was validated among a bariatric population, while none of the tools validated in previous studies were validated in this population. Conclusion: Few studies in bariatric populations used a dietary assessment tool that had been validated in this population. Additional studies are needed to develop valid and robust dietary assessment tools to improve the quality of nutritional studies among bariatric patients.     

Changes in Food Choice,Taste, Desire,and Enjoyment 1 Year after Sleeve Gastrectomy: A Prospective Study

Obesity is a well-recognized global health problem, and bariatric surgery (BS)-induced weight reduction has been demonstrated to improve survival and obesity-related conditions. Sleeve gastrectomy (SG) is actually one of the most performed bariatric procedures. The underlying mechanisms of weight loss and its maintenance after SG are not yet fully understood. However, changes to the taste function could be a contributing factor. Data on the extent of the phenomenon are limited. The primary objective was to assess, through validated questionnaires, the percentage of patients who report an altered perception of post-SG taste and compare the frequency of intake of the different food classes before SG and after 1 year follow-up. The secondary objective was to evaluate the total body weight change. Materials and Methods: We prospectively investigated the changes in food choice and gustatory sensitivity of 52 patients (55.8% females) 12 months after SG. The mean initial weight and body mass index (BMI) were 130.9 ± 24.7 kg and 47.4 ± 7.1 kg/m², respectively. The frequency of food intake was assessed by food-frequency questionnaire, while changes in taste perception were assessed using the taste desire and enjoyment change questionnaire. The change in total body weight was also assessed. Results: A significant decrease in the intake frequency of bread and crackers (p < 0.001), dairy products and fats (p < 0.001), sweets and snacks (p < 0.001) and soft drinks (p < 0.001), and a significant increase in the frequency of vegetable and fruit consumption (p < 0.001) were observed at 12 months after SG in both genders. On the contrary, we found no significant changes in the frequency of meat and fish intake in females (p = 0.204), whereas a significant change was found in males (p = 0.028). Changes in perceived taste intensity of fatty foods (p = 0.021) and tart foods (p = 0.006) for females and taste of bitter foods for females and males (p = 0.002; p = 0.017) were found. Regarding the change in food desire for both genders, there was a decrease in the desire for sweet, fatty, and salty foods, whereas there was an increasing trend in the desire for tart foods, especially for females. Significant reduction in total body weight and BMI was observed in both genders at the time of follow-up. Conclusions: Based on our findings, we are able to support the evidence that changes in taste, desire, and enjoyment of taste are very common after SG, with a reduced preference for food with high sugar and fat content and an increased postoperative preference for low-sugar and -fat foods. However, further investigation is needed to clarify this issue. The molecular, hormonal, and central mechanisms underlying these changes in taste perception need to be further elucidated, as they could identify new targets able to modify obesogenic eating behavior, opening up a novel personalized therapeutic approach to obesity.     

The Development of Feeding and Eating Disorders after Bariatric Surgery: A Systematic Review and Meta-Analysis

Background: Patients in the postoperative period following bariatric surgery are at risk of developing eating disorders. This study aims to analyze the relation between bariatric surgery and the development and recurrence of eating disorders. Material and methods: A literature review was carried out on 15 November 2020. Fourteen studies that met the eligibility criteria were included for qualitative synthesis, and 7 studies for meta-analysis. Results: The prevalence of eating disorders in the postoperative period was 7.83%, based on the 7 studies in the meta-analysis. Binge eating disorder alone was 3.81%, which was the most significant factor, and addressed in 6 of these studies. Conclusion: The investigated studies have significant methodological limitations in assessing the relation between bariatric surgery and eating disorders, since they mostly present data on prevalence. PROSPERO CRD42019135614.     

Prehabilitation for Bariatric Surgery: A Randomized,Controlled Trial Protocol and Pilot Study

Bariatric surgery is the most efficacious treatment for obesity, though it is not free from complications. Preoperative conditioning has proved beneficial in various clinical contexts, but the evidence is scarce on the role of prehabilitation in bariatric surgery. We describe the protocol and pilot study of a randomized (ratio 1:1), parallel, controlled trial assessing the effect of a physical conditioning and respiratory muscle training programme, added to a standard 8-week group intervention based on therapeutical education and cognitive-behavioural therapy, in patients awaiting bariatric surgery. The primary outcome is preoperative weight-loss. Secondary outcomes include associated comorbidity, eating behaviour, physical activity, quality of life, and short-term postoperative complications. A pilot sample of 15 participants has been randomized to the intervention or control groups and their baseline features and results are described. Only 5 patients completed the group programme and returned for assessment. Measures to improve adherence will be implemented and once the COVID-19 pandemic allows, the clinical trial will start. This is the first randomized, clinical trial assessing the effect of physical and respiratory prehabilitation, added to standard group education and cognitive-behavioural intervention in obese patients on the waiting list for bariatric surgery. Clinical Trial Registration: NCT0404636.     

Gut Microbiota Profile in Adults Undergoing Bariatric Surgery: A Systematic Review

Gut microbiota (GM) after bariatric surgery (BS) has been considered as a factor associated with metabolic improvements and weight loss. In this systematic review, we evaluate changes in the GM, characterized by 16S rRNA and metagenomics techniques, in obese adults who received BS. The PubMed, Scopus, Web of Science, and LILACS databases were searched. Two independent reviewers analyzed articles published in the last ten years, using Rayyan QCRI. The initial search resulted in 1275 documents, and 18 clinical trials were included after the exclusion criteria were applied. The predominance of intestinal bacteria phyla varied among studies; however, most of them reported a greater amount of Bacteroidetes (B), Proteobacteria (P), and diversity (D) after BS. Firmicutes (F), B, and the (F/B) ratio was inconsistent, increasing or decreasing after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) were conducted, compared to before surgery. There was a reduction in the relative proportion of F. Moreover, a higher proportion of Actinobacteria (A) was observed after RYGB was conducted. However, the same was not identified when SG procedures were applied. Genera abundance and bacteria predominance varied according to the surgical procedure, with limited data regarding the impact on phyla. The present study was approved by PROSPERO, under registration number CRD42020209509.     

TAS1R3 and TAS2R38 Polymorphisms Affect Sweet Taste Perception: An Observational Study on Healthy and Obese Subjects

Background: The inter-individual differences in taste perception find a possible rationale in genetic variations. We verified whether the presence of four different single nucleotide polymorphisms (SNPs) in genes encoding for bitter (TAS2R38; 145G > C; 785T > C) and sweet (TAS1R3; −1572C > T; −1266C > T) taste receptors influenced the recognition of the basic tastes. Furthermore, we tested if the allelic distribution of such SNPs varied according to BMI and whether the associations between SNPs and taste recognition were influenced by the presence of overweight/obesity. Methods: DNA of 85 overweight/obese patients and 57 normal weight volunteers was used to investigate the SNPs. For the taste test, filter paper strips were applied. Each of the basic tastes (sweet, sour, salty, bitter) plus pure rapeseed oil, and water were tested. Results: Individuals carrying the AV/AV diplotype of the TAS2R38 gene (A49P G/G and V262 T/T) were less sensitive to sweet taste recognition. These alterations remained significant after adjustment for gender and BMI. Moreover, a significant decrease in overall taste recognition associated with BMI and age was found. There was no significant difference in allelic distribution for the investigated polymorphisms between normal and overweight/obese patients. Conclusions: Our findings suggest that overall taste recognition depends on age and BMI. In the total population, the inter-individual ability to identify the sweet taste at different concentrations was related to the presence of at least one genetic variant for the bitter receptor gene but not to the BMI.     

A Comparison of Total Food Intake at a Personalised Buffet in People with Obesity,before and 24 Months after Roux-en-Y-Gastric Bypass Surgery

Long-term reductions in the quantity of food consumed, and a shift in intake away from energy dense foods have both been implicated in the potent bariatric effects of Roux-en-Y gastric bypass (RYGB) surgery. We hypothesised that relative to pre-operative assessment, a stereotypical shift to lower intake would be observed at a personalised ad libitum buffet meal 24 months after RYGB, driven in part by decreased selection of high energy density items. At pre-operative baseline, participants (n = 14) rated their preference for 72 individual food items, each of these mapping to one of six categories encompassing high and low-fat choices in combination with sugar, complex carbohydrate or and protein. An 18-item buffet meal was created for each participant based on expressed preferences. Overall energy intake was reduced on average by 60% at the 24-month buffet meal. Reductions in intake were seen across all six food categories. Decreases in the overall intake of all individual macronutrient groups were marked and were generally proportional to reductions in total caloric intake. Patterns of preference and intake, both at baseline and at follow-up appear more idiosyncratic than has been previously suggested by verbal reporting. The data emphasise the consistency with which reductions in ad libitum food intake occur as a sequel of RYGB, this being maintained in the setting of a self-selected ad libitum buffet meal. Exploratory analysis of the data also supports prior reports of a possible relative increase in the proportional intake of protein after RYGB.     

Obesity and Psychological Factors Associated with Weight Loss after Bariatric Surgery: A Longitudinal Study

Bariatric surgery is indicated for treatment of severely obese people and can lead to significant weight loss as well as reduction of comorbidities associated with obesity. The present study aims to investigate the relationship between different psychological factors (e.g., tendency to binge eating, impulsivity, alexithymia), adherence to the nutritional plan, and weight loss after bariatric surgery. Forty-five candidates for bariatric surgery accessing a center for the care of obesity were assessed at T0 (pre-surgery) and T1 (6 months post-surgery) through anthropometric and psychometric measures. Simple linear correlations and linear regressions were conducted to evaluate the relationship between the psychological variables, adherence to nutritional plan, and weight loss 6 months after bariatric surgery. Non-planning impulsivity was the principal factor that succeeded in explaining adherence to the diet plan among all the variables considered. Adherence to the nutritional plan and non-planning impulsivity were considered reliable short-term predictors of weight loss after bariatric surgery. This evidence explains the usefulness of promoting research on psychological predictors of outcome in bariatric surgery. Mid- and long-term weight maintenance and quality of life need to be investigated through further follow-up.     

Endovascular Bariatric Surgery as Novel Minimally Invasive Technique for Weight Management in the Morbidly Obese: Review of the Literature

Nowadays, obesity represents one of the most unresolved global pandemics, posing a critical health issue in developed countries. According to the World Health Organization, its prevalence has tripled since 1975, reaching a prevalence of 13% of the world population in 2016. Indeed, as obesity increases worldwide, novel strategies to fight this condition are of the utmost importance to reduce obese-related morbidity and overall mortality related to its complications. Early experimental and initial clinical data have suggested that endovascular bariatric surgery (EBS) may be a promising technique to reduce weight and hormonal imbalance in the obese population. Compared to open bariatric surgery and minimally invasive surgery (MIS), EBS is much less invasive, well tolerated, with a shorter recovery time, and is probably cost-saving. However, there are still several technical aspects to investigate before EBS can be routinely offered to all obese patients. Further prospective studies and eventually a randomized trial comparing open bariatric surgery vs. EBS are needed, powered for clinically relevant outcomes, and with adequate follow-up. Yet, EBS may already appear as an appealing alternative treatment for weight management and cardiovascular prevention in morbidly obese patients at high surgical risk.     

Clinical Impact of Mediterranean Diet Adherence before and after Bariatric Surgery: A Narrative Review

The population suffering from obesity is rapidly increasing all over the world. Bariatric surgery has shown to be the treatment of choice in patients with severe obesity. A Mediterranean diet has long been acknowledged to be one of the healthiest dietary patterns associated with a lower incidence of many chronic diseases. The aim of the present narrative review is to summarize the existing research on the clinical impact of a Mediterranean diet before and after bariatric surgery, focusing on its effects on weight loss and improvement in comorbidities. Although the current knowledge is limited, this information could add value and emphasize the importance of adopting a Mediterranean diet before and after bariatric surgery.     

Adequacy and Vitamin D in the Preoperative Period of Roux-en-Y Gastric Bypass,Bariatric Surgery,Can Protect Metabolic Health in Metabolically Healthy and Unhealthy Individuals

Evaluating the influence of vitamin D concentrations together with preoperative metabolic phenotypes on remission of chronic noncommunicable diseases (CNCDs) after 6 months of Roux-en-Y gastric bypass (RYGB). Cross-sectional analytical study comprising 30 adult individuals who were assessed preoperatively (T0) and 6 months (T1) after undergoing RYGB. Participants were distributed preoperatively into metabolically healthy obese (MHO) and metabolically unhealthy obese (MUHO) individuals according to HOMA-IR classification and to the adequacy and inadequacy of vitamin D concentrations in the form of 25(OH)D. All participants were assessed for anthropometric characteristics, biochemical variables, and presence of CNCDs. The statistical program used was the SPSS version 21. In face of vitamin D adequacy and regardless of the metabolic phenotype classification in the preoperative period, the means found for HOMA-IR allowed us to define them as metabolically healthy 6 months after RYGB. Only those with vitamin D inadequacy with the MUHO phenotype showed better results regarding the reduction of glucose that accompanied the shift in serum 25(OH)D concentrations from deficient to insufficient. It is possible that preoperative vitamin D adequacy, even in the presence of an unhealthy phenotype, may contribute to the reduction of dyslipidemia and improvement in cholesterol. It is suggested that preoperative vitamin D adequacy in both phenotypes may have a protective effect on metabolic health.     

Costs and Outcomes of Increasing Access to Bariatric Surgery: Cohort Study and Cost-Effectiveness Analysis Using Electronic Health Records

Objectives

To estimate costs and outcomes of increasing access to bariatric surgery in obese adults and in population subgroups of age, sex, deprivation, comorbidity, and obesity category.

Staple Food Preference and Obesity Phenotypes: The Regional Ethnic Cohort Study in Northwest China

Staple food preference vary in populations, but evidence of its associations with obesity phenotypes are limited. Using baseline data (n = 105,840) of the Regional Ethnic Cohort Study in Northwest China, staple food preference was defined according to the intake frequency of rice and wheat. Overall and specifically abdominal fat accumulation were determined by excessive body fat percentage and waist circumference. Logistic regression and equal frequency substitution methods were used to evaluate the associations. We observed rice preference (consuming rice more frequently than wheat; 7.84% for men and 8.28% for women) was associated with a lower risk of excessive body fat (OR, 0.743; 95%CI, 0.669–0.826) and central obesity (OR, 0.886; 95%CI, 0.807–0.971) in men; and with lower risk of central obesity (OR, 0.898; 95%CI, 0.836–0.964) in women, compared with their wheat preference counterparties. Furthermore, similar but stronger inverse associations were observed in participants with normal body mass index. Wheat-to-rice (5 times/week) reallocations were associated with a 36.5% lower risk of normal-weight obesity in men and a 20.5% lower risk of normal-weight central obesity in women. Our data suggest that, compared with wheat, rice preference could be associated with lower odds ratios of certain obesity phenotypes in the Northwest Chinese population.     

Alterations in Fecal Short-Chain Fatty Acids after Bariatric Surgery: Relationship with Dietary Intake and Weight Loss

Bariatric surgery is associated with weight loss attributed to reduced caloric intake, mechanical changes, and alterations in gut hormones. However, some studies have suggested a heightened incidence of colorectal cancer (CRC) has been associated with bariatric surgery, emphasizing the importance of identifying mechanisms of risk. The objective of this study was to determine if bariatric surgery is associated with decreases in fecal short-chain fatty acids (SCFA), a group of bacterial metabolites of fiber. Fecal samples (n = 22) were collected pre- (~6 weeks) and post-bariatric surgery (~4 months) in patients undergoing Roux-en-Y gastric bypass and sleeve gastrectomy. SCFA levels were quantified using liquid chromatography/mass spectrometry. Dietary intake was quantified using 24-h dietary recalls. Using an aggregate variable, straight SCFAs significantly decreased by 27% from pre- to post-surgery, specifically acetate, propionate, butyrate, and valerate. Pre-surgery weight was inversely associated with butyrate, with no association remaining post-surgery. Multiple food groups were positively (sugars, milk, and red and orange vegetables) and inversely (animal protein) associated with SCFA levels. Our results suggest a potential mechanism linking dietary intake and SCFA levels with CRC risk post-bariatric surgery with implications for interventions to increase SCFA levels.     

Gut Microbiota and Mycobiota Evolution Is Linked to Memory Improvement after Bariatric Surgery in Obese Patients: A Pilot Study

Patients with obesity are known to exhibit gut microbiota dysbiosis and memory deficits. Bariatric surgery (BS) is currently the most efficient anti-obesity treatment and may improve both gut dysbiosis and cognition. However, no study has investigated association between changes of gut microbiota and cognitive function after BS. We prospectively evaluated 13 obese patients on anthropometric data, memory functions, and gut microbiota-mycobiota before and six months after BS. The Rey Auditory Verbal Learning Test (AVLT) and the symbol span (SS) of the Weschler Memory Scale were used to assess verbal and working memory, respectively. Fecal microbiota and mycobiota were longitudinally analyzed by 16S and ITS2 rRNA sequencing respectively. AVLT and SS scores were significantly improved after BS (AVLT scores: 9.7 ± 1.7 vs. 11.2 ± 1.9, p = 0.02, and SS scores: 9.7 ± 23.0 vs. 11.6 ± 2.9, p = 0.05). An increase in bacterial alpha-diversity, and Ruminococcaceae, Prevotella, Agaricus, Rhodotorula, Dipodascus, Malassezia, and Mucor were significantly associated with AVLT score improvement after BS, while an increase in Prevotella and a decrease in Clostridium, Akkermansia, Dipodascus and Candida were linked to SS scores improvement. We identified several changes in the microbial communities that differ according to the improvement of either the verbal or working memories, suggesting a complex gut-brain-axis that evolves after BS.     

Cultural Influences on the Regulation of Energy Intake and Obesity: A Qualitative Study Comparing Food Customs and Attitudes to Eating in Adults from France and the United States

(1) Background: The influence of food culture on eating behavior and obesity risk is poorly understood. (2) Methods: In this qualitative study, 25 adults in France with or without overweight/obesity participated in semi-structured interviews (n = 10) or focus groups (n = 15) to examine attitudes to food consumption and external pressures that influence eating behavior and weight management. Results were compared to an equivalent study conducted in the United States, thereby contrasting two countries with markedly different rates of obesity. Emerging key themes in the French data were identified through coding using a reflexive approach. (3) Results: The main themes identified were: (1) influence of commensality, social interactions, and pleasure from eating on eating behavior, (2) having a balanced and holistic approach to nutrition, (3) the role of environmental concerns in food consumption, (4) relationship with “natural” products (idealized) and food processing (demonized), (5) perceptions of weight status and management. Stress and difficulties in hunger cue discernment were viewed as important obstacles to weight management in both countries. External pressures were described as a major factor that explicitly influences food consumption in the U.S., while there was an implicit influence of external pressures through eating-related social interactions in France. In France, products considered “natural” where idealized and juxtaposed against processed and “industrial” products, whereas this was not a salient aspect in the U.S. (4) Conclusions: This first comparative qualitative study assessing aspects of food culture and eating behaviors across countries identifies both common and divergent attitudes to food and eating behavior. Further studies are needed to inform the development of effective behavioral interventions to address obesity in different populations.     

Pregnancy after Bariatric Surgery: A Nested Case-Control Study of Risk Factors for Small for Gestational Age Babies in AURORA

Bariatric surgery prior to pregnancy is a significant risk factor for small for gestational age (SGA) babies. This case-control study investigated differences between mothers delivering an SGA baby following bariatric surgery, compared to those delivering an appropriate for gestational age (AGA) baby. Out of 129 babies born to mothers in the AURORA cohort study, 25 were SGA (<10th percentile) and 97 were AGA (10th–90th percentile). Higher gestational weight gain (GWG) was significantly associated with decreased odds of SGA (aOR per kg 0.92, 95% CI 0.85–0.99). According to the Institute of Medicine GWG guidelines, 44% of SGA mothers had ‘inadequate’ GWG compared to 17% of AGA mothers. Nearly half of the mothers had ‘excessive’ GWG yet still gave birth to an SGA or AGA baby. Mothers of SGA babies lost more weight following bariatric surgery (45.6 ± 14.4 kg vs. 39.0 ± 17.9 kg). Women who reported receiving nutritional advice following bariatric surgery were significantly less likely to have an SGA baby (aOR 0.15, 95% CI 0.0.4–0.55). Women with a history of bariatric surgery should be provided with specialized support before and during pregnancy to encourage adequate nutritional intake and weight gain to support healthy fetal growth.