Experiences of Individuals Undergoing Bariatric Surgery Regarding Nutritional Behaviors: A Qualitative Study

Study design

In this study, phenomenology, a qualitative research method, was used within the framework of the concept of “nutritional behaviors.”^14,15 This approach is an inductive method that explains an event that is noticed in daily life but whose details are not understood, based on human experiences. This qualitative study utilized a hermeneutic phenomenological design and a criterion sampling strategy from among purposeful sampling methods to explore the experiences of individuals who underwent bariatric surgery regarding their nutritional behaviors.

Participants and setting

The study sample consisted of 35 individuals who had received sleeve gastrectomy (SG) at least 6 months prior to the study and were reachable via contact information. Inclusion criteria were: (a) volunteering to participate in to study, (b) aged 18–65, (c) literate, and (d) having undergone SG at least 6 months before the study. Exclusion criteria were: (a) unwillingness to participate in the study, and (b) SG surgery performed less than 6 months prior to the study. All potential participants were contacted by phone to confirm their willingness to participate. Participants who did not consent to having their voices recorded during the study and who did not attend when invited to the interview were excluded from the study. Data saturation was reached after six interviews, and the final sample consisted of 13 participants who provided consent.

Data collection

The research data were collected from patients who underwent bariatric surgery and were followed up at the Obesity Center of an Education and Research Hospital in Türkiye between November 2021 and March 2023, and who agreed to participate in the study after the initial telephone interview.

Data were collected through individual in-depth interviews using a semi-structured questionnaire developed based on existing literature and prepared with expert input.^11,15,16 A data collection form prepared for the characteristics of the participants was also used. A pilot interview was conducted with one participant (excluded from the study) to refine the questions. Following the pilot interview, the in-depth interview questions were modified accordingly (Table 1). Participants were asked warm-up questions to observe their behavior, and notes were taken during the interview, while audio recordings were made. Interviews were held at a time and place convenient for participants, following verbal and written consent. Each participant interview was conducted separately with each patient, with audio recordings made in quiet, calm interview settings at times convenient. Each interview lasted 55–70 min. The interviewer, an experienced nurse trained in qualitative research, facilitated a comprehensive understanding of participants’ experiences.

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Table 1.

Interview Guide

Interview guide
1. How did bariatric surgery affect your eating behavior?
2. How did your eating behavior change compared to before surgery?
3. What are your difficulties in adapting to your new life and diet? How do you cope with these difficulties?

Data analysis

Data were analyzed using MAXQDA 2022 software with inductive qualitative content analysis. ¹⁷ This method involved analyzing both overt and latent content in participants’ statements to identify concepts and relationships. ¹⁸ Creswell’s qualitative data analysis steps were followed ¹⁹ :

Audio recordings were transcribed within 24 h, and transcripts were repeatedly read to holistically evaluate participants’ experiences.

Rigor

In qualitative research, rigor is assessed through consistency, credibility, transferability, and confirmability.^17,20 In this regard, the conversion of audio recordings was into text after 24 h. To ensure consistency, data were collected by a single researcher and coded by both researchers, and the codes were independently reviewed. Discrepancies were resolved through discussion. Credibility was enhanced through prolonged engagement, member checking, and expert review. ²¹ One participant was interviewed to confirm whether they had experienced the main themes and subthemes identified. Transferability was achieved through purposive sampling and detailed descriptions of the research process and participant statements.^17,21 Confirmability was ensured by consulting an external expert to review the data, codes, and themes. ²¹ The consolidated criteria for reporting qualitative research checklist was used to enhance reporting quality.

Ethics approval

Ethical approval was obtained from the Clinical Research Ethics Committee of Health Science University (approval number: 2021/16, date: September 23, 2021), and institutional approval was also obtained from the institution where the study was to be conducted. Following the provision of information regarding the objectives of the study, its methodology, the utilization of audio recordings, and the confidentiality of data, participants provided written, signed, and verbal consent using an “Informed Consent Form” prepared in accordance with the Helsinki Declaration. They were assured of the confidentiality of their identities and informed of their right to withdraw without penalty at any stage.

Demographic and surgical characteristics

The mean age of the participants was 33.23 ± 6.78 years. Ten of the participants were female, nine were married, six were undergraduate graduates, and five were civil servants. The mean preoperative BMI of the participants was 44.81 ± 4.78 kg/m², and the mean postoperative BMI was 27.52 ± 3.14 kg/m². The mean postoperative weight loss was 50.19 ± 12.94 kg. The demographic and surgical characteristics of the 13 participants (identified as K1–K13 to maintain confidentiality) are presented in Table 2. Table 3 summarizes the main themes and subthemes from the interviews.

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Table 2.

Demographic and Surgical Intervention Characteristics of the Participants

Participant code	Age	Gender	Marital status	Education level	Job	Postoperative interview date	Diagnosed disease	Presurgical BMI*	Postsurgical BMI*	Total weight lost
K1	40	Men	Single	Bachelor	Civil servant	After 20 months	Yes	38.70	24.70	41
K2	41	Women	Married	High school	Housewife	After 15 months	Yes	50.41	22.64	65
K3	37	Women	Single	Bachelor	Self employment	After 28 months	No	35.31	26.15	25
K4	39	Men	Married	Master	Civil servant	After 18 months	Yes	47.00	27.50	65.5
K5	25	Women	Married	Bachelor	Civil servant	After 25 months	No	43.60	22.00	56
K6	23	Women	Single	High school	Self employment	After 9 months	No	44.98	31.49	39
K7	38	Women	Married	Bachelor	Housewife	After 11 months	No	45.40	27.10	55
K8	35	Men	Married	Bachelor	Tradesman	After 6 months	No	42.20	31.00	38
K9	35	Women	Married	High school	Civil servant	After 17 months	No	46.28	26.45	54
K10	39	Women	Married	Primary school	Housewife	After 20 months	Yes	41.80	30.47	42
K11	28	Women	Married	Bachelor	Civil servant	After 14 months	No	54.08	30.42	70
K12	30	Women	Married	Primary school	Housewife	After 14 months	Yes	46.31	30.42	47
K13	22	Women	Single	High school	Self employment	After 17 months	No	46.49	27.43	55
	Average (X ± SD*)Age							Average (X ± SD)*kg/m2*	Average (X ± SD)*kg/m2*	Average (X ± SD)*kg*
	33.23 ± 6.78							44.81 ± 4.78	27.52 ± 3.14	50.19 ± 12.94

*Mean: abbreviation.

BMI*, body mass index; SD*, standard deviation.

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Table 3.

Main Themes and Subthemes

Main themes	Main themes	Subthemes
1. Nutritional behavior after surgery	First 3 months	Liquid nutritions Nutritioning with puree Consuming protein powder/eating small pieces Vitamin supplements
	Sixth month and beyond	Meat consumption
2. Changes in eating behavior after surgery		Physical activity Water consumption Maintaining old habits Dietary pattern Food consumption
3. Challenges associated with bariatric surgery		Gastrointestinal symptoms Difficulty adjusting to body image Fear of returning to the old Emotional challenges
4. Coping strategies		Being determined Feeling strong Sense of achievement Support of family and friends

Nutritional behavior after surgery

SG entails the surgical removal of about 80% of the stomach, which results in accelerated gastric transit and delayed emptying. ²² This results in reduced calorie intake due to decreased levels of appetite-suppressing hormones. ²² Studies indicate that a high-protein liquid diet begins on the second or third day and lasts for 10–12 days, and that this period can be shortened or extended depending on the patient’s tolerance. ¹⁰ In addition to the patients’ diet, it is stated that unsweetened apple or grape juice, plain yogurt, soy milk with protein powder, low-fat, low-carbohydrate, high-protein beverages, and whey or skim milk (1% fat) can be added. ²³ Consistent with these studies,^10,23 participants in Aydin’s study reported starting with liquid nutrition for the first 15 days postsurgery, followed by a transition to pureed foods. ²⁴ These findings align with the challenges reported by our participants, such as reduced food intake and difficulties adapting to new dietary patterns.

The “puree diet” emphasizes high-protein, low-fat foods in a soft or ground consistency, such as egg whites, minced beef, lean sauces, boiled legumes, low-fat cheese, and yogurt. Patients who tolerate high-protein foods can also include peeled fruits and well-cooked soft vegetables. ¹⁰ Participants in our study reported successfully consuming these foods during the puree phase. However, challenges such as prolonged reliance on pureed foods and fatigue despite vitamin supplementation were noted, consistent with findings from Aydin’s study. ²⁴

Postoperative nutrient deficiencies, including vitamin B12, calcium, folate, vitamin D, and iron, are common due to reduced absorption, decreased intake, and poor nutrition. ¹ The mitigation of these issues is recommended by Liu and Irwin through the practice of slow and measured eating, in addition to smaller bite sizes. This recommendation aligns with the experiences of our participants. ²⁵

Gungor emphasizes the importance of a balanced and varied diet during the postoperative phase, recommending a daily protein intake of 60–80 g or 1.1 g/kg.^10,26 Consistent with this, one participant in Aydin’s study reported prioritizing high-protein foods. ²⁴ In our study, participants initially consumed pureed meat in small quantities during the first 3 months, transitioning to whole meat by the sixth month. They also incorporated protein-rich foods such as eggs, cheese, milk, and yogurt into their diets. These findings align with existing literature on postoperative nutritional practices.

Changes in eating behavior after surgery

Physical activity is crucial for maintaining weight loss after bariatric surgery.^27,28 Research indicates that 57.8% of women and 60.2% of men participate in physical exercise after surgery, commonly preferring walking and swimming.^18,28,29 Our findings align with these results.

Adequate hydration is equally important, with literature recommending a daily fluid intake of at least 1.5 L. ³⁰ Participants in our study adhered to this guideline, consistent with previous research.

Grazing, nighttime eating, and sweet consumption are linked to weight regain and reduced quality of life postsurgery.^30,31 In Aydin’s study, participants reported conscious eating but occasionally reverted to old habits, such as consuming junk food or sweets. ²⁴ Sweet eating behaviors are prevalent in 36.4–60% of bariatric patients, particularly after SG.^30,32,33 Our participants also occasionally exhibited these behaviors, reflecting the challenges of maintaining new dietary patterns.

Post-SG, the stomach’s reduced capacity necessitates small, well-chewed meals to prevent nausea and vomiting.^10,22,25 Studies recommend three main meals and three snacks daily, with fluid intake avoided 30 min before, during, and immediately after meals.^18,24,26,34 Yuksel emphasizes avoiding simultaneous solid and liquid consumption to prevent vomiting. ³⁵ These studies align with our participants’ experiences.

Reduced hunger sensations postsurgery is attributed to decreased hormone levels that stimulate appetite and the brain–gut connection. ³⁰ Pepino et al. found that bariatric patients reported fewer food cravings and reduced appetite, ³⁶ consistent with our participants’ decreased eating frequency and cessation of nighttime eating.

Bariatric surgery promotes healthy eating and increased physical activity, regardless of the surgical technique.^37,38 Participants in our study, like those in Dizlek and Catal’s and Bayraktaroglu’s studies, avoided pastries, fatty foods, sugary drinks, and carbohydrates while adopting healthier cooking methods.^18,39 These findings highlight the importance of dietary and lifestyle modifications in postoperative success.

Challenges associated with bariatric surgery

As a restrictive procedure, SG may result in complications including malnutrition, reflux-gastritis, persistent vomiting, gastric stenosis, bleeding, thrombosis, staple line leaks, and atelectasis. ²² Participants in Aydin’s study reported side effects such as nausea, vomiting, weakness, hair loss, cold intolerance, and stomach issues. ²⁴

Dumping syndrome, affecting 85% of patients with gastric restriction, manifests as sweating, dizziness, tachycardia, nausea, flushing, abdominal fullness, diarrhea, and cramps within 10–30 min postmeal, lasting up to 60 min. ³⁰ These symptoms were observed in many of our participants.

Postoperative adaptation challenges include skin sagging, which can affect self-esteem, physical appearance, and sexuality.^18,40 A participant in Dizlek and Catal’s study expressed dissatisfaction with body sagging. ¹⁸ In addition, reduced food intake due to stomach restriction and fear of weight regain are also common.^31,41 Dysphagia or obstruction may further limit dietary intake. ³⁰ Besides, overeating often leads to intense vomiting, as reported by Aydin and Yuksel, particularly when solid and liquid foods are consumed together.^24,35 These findings align with our participants’ experiences.

Psychosocial improvements, including body image, self-esteem, and quality of life, often emerge within the first few years after surgery, though this recovery process can take time. ⁴²

The emotional responses observed in our participants, such as crying, align with typical coping strategies reported in the literature. ⁴³

Coping strategies

Participants in our study reported feeling content and motivated as they lost weight, adopting healthy coping mechanisms to achieve their ideal lives. Themes such as “happiness, achievement, rebirth, gaining a second chance at life, and escaping the past,” ¹⁸ “a new life,”^44,45 and “getting my life back” ⁴⁵ are well-documented in the literature.

Aydin’s study highlighted the importance of social support in sustaining weight loss, noting that while some participants received strong support, others, particularly women, struggled with isolation. ²⁴ Support of family and friends is crucial for long-term success postsurgery. ⁴⁵ Our participants also emphasized the role of family and friends support in overcoming challenges, though they occasionally experienced emotional difficulties, such as crying, when faced with negativity.

Strengths and limitations

The study’s strengths include employing a hermeneutic phenomenological approach, offering rich insights into the nutritional practices and lived experiences of individuals’ postbariatric surgery. The inclusion of 13 participants with diverse demographic characteristics allowed for a rich exploration of various perspectives, and data saturation was achieved, enhancing the reliability and validity of the findings. The results align with existing literature, offering valuable contributions to understanding postoperative dietary behaviors, challenges, and coping mechanisms. Ethical approval and participant consent further strengthened the study’s credibility. Nonetheless, several limitations should be acknowledged. The limited sample size constrains the generalizability of the results, and the necessity of audio recordings may have discouraged some individuals from participating. Additionally, the single-center design limits the broader applicability of the results, and the lack of long-term follow-up prevents an assessment of sustained dietary and lifestyle changes. Future studies with larger, multicenter samples and longitudinal designs are recommended to address these limitations.