Comparison of Dietary Quality and Surgical Satisfaction Between Patients With Suboptimal and Optimal Weight Loss After Sleeve Gastrectomy Using Food Tolerance Score and Bariatric Analysis and Reporting Outcome System Questionnaires

Abstract

Purpose

This study aimed to assess the association of dietary quality and surgical satisfaction with the amount of total weight loss (TWL) 1 year after laparoscopic sleeve gastrectomy (LSG) using the food tolerance score (FTS) and Bariatric Analysis and Reporting Outcome System (BAROS) questionnaires.

Materials and Methods

This single-center retrospective study included patients who underwent LSG due to morbid obesity. Only those who have 1-year follow-up data were included and divided into 2 groups: suboptimal TWL (STWL) ≤20% and optimal TWL (OTWL) >20%. Clinical data and questionnaires recorded 1 year after surgery were collected. FTS was used to evaluate the degree of food tolerance, and BAROS assessed surgical outcomes, including weight loss, comorbidity changes, and quality of life (QoL). The total FTS and BAROS scores of the 2 groups were compared.

Results

Of 580 patients, 159 were included. Patients in STWL (n=17) were significantly older than those in OTWL (n=142) (42.24±9.28 vs. 35.92±8.71 years old, P=0.006). The total FTS (1–30 points) for STWL and OTWL were 24.88±3.43 and 25.04±3.14, respectively (P=0.845). Although the total BAROS scores (maximum: 9 points) were significantly lower in STWL than in OTWL (5.96±1.48 vs. 7.20±1.40, P<0.001). The only variable that made this difference was weight loss. There were no significant differences in other variables, such as medical conditions, QoL, and complications.

Conclusion

In terms of FTS and BAROS score, there is no difference in postoperative satisfaction and QoL between STWL and OTWL after LSG, except for the degree of weight loss.

INTRODUCTION

Obesity has reached epidemic rates globally owing to its high caloric consumption and sedentary lifestyles. More than 1.5 billion adults over the age of 20 are considered overweight or obese [1]. Obesity is not only a cosmetic problem but also increases with obesity-related chronic diseases, such as hypertension, diabetes, hyperlipidemia, gastroesophageal reflux, and obstructive sleep apnea. Severe obesity requires active treatment [2], and bariatric surgery is the only proven treatment for long-term weight loss in severely obese patients.

Laparoscopic sleeve gastrectomy (LSG), a bariatric surgery, is technically simple compared to other surgeries because it does not require anastomosis. Its long-term surgical safety and substantial weight loss have also been proven and compared with other bariatric procedures [3,4,5]. In 2014, LSG was the most widely practiced type of bariatric surgery worldwide. By 2016, it accounted for more than 50% of bariatric surgeries. Increased use of LSG is attributed to lower morbidity and mortality rates and simpler technique compared to Roux-en-Y gastric bypass (RYGB).

Bariatric surgeries improve not only weight loss but also quality of life (QoL). The food tolerance score (FTS) is a questionnaire used to evaluate the degree of food tolerance after bariatric surgery [6]. The Bariatric Analysis and Reporting Outcome System (BAROS) was first introduced in 1998 to assess weight loss, improvement of obesity-related comorbidities, and QoL [7]. FTS and BAROS quantitatively measure QoL after different types of bariatric surgery. Previous studies have investigated food tolerance in patients who underwent bariatric surgeries on 1-year follow-up and reported that the short-term score improvement was most notable in the order LSG, followed by RYGB, then gastric band [8,9]. Other studies have reported similar improvements in terms of weight reduction and BAROS on 2-year follow-up after LSG and RYGB [10,11]. However, studies using both FTS and BAROS questionnaires to evaluate eating tolerance and postoperative QoL after LSG in morbid Korean patients are scarce [12].

This study aimed to evaluate whether achieving optimal TWL (OTWL) 1 year after LSG influences surgical satisfaction and QoL, measured using FTS and BAROS.

MATERIALS AND METHODS

1. Patient selection

This was a single-center, retrospective study. Among the patients who underwent LSG from January 2019 to December 2020 at Gachon University Gil Medical Center in Korea due to morbid obesity, only those who had been on outpatient follow-up for >1 year were included in this study. All surgeries during the study period were performed by an experienced bariatric surgeon (S.M.K.). The study protocol was approved by the institutional review board of the Gachon University Gil Medical Center (GFIRB2020- 406).

2. Data collection

Basic clinical data and results of postoperative questionnaires were also obtained. The FTS and BAROS scores for all patients were compiled 1 year after surgery. The total FTS and BAROS scores were calculated based on questionnaires completed by patients after surgery. Similar to previous studies [13,14,15,16,17], the patients were divided into 2 groups according to the total weight loss (TWL) 1 year after LSG and analyzed comparatively: suboptimal TWL (STWL) ≤20% vs. OTWL >20%.

1) Food tolerance score (FTS) questionnaire

The total FTS score was recorded by the patients after surgery and divided into 3 main parts [6]. The first was to choose the current meal satisfaction from very poor (1 point) to excellent (5 points). The second probed on specific food tolerance, divided into 8 items: red meat, white meat, salad, vegetable fruit, bread, rice, noodles, and fish. For each item, patients chose from not eating at all (0 points) to easy to eat (2 points). Finally, the vomiting or reflux score was calculated based on the frequency with which symptoms occurred: 3 points for asymptomatic cases, 1–2 points for occurrences twice a week, and 0 points for daily occurrence and the need for medication.

2) BAROS

BAROS is a questionnaire that comprehensively evaluates the effectiveness of bariatric surgery [18]. BAROS scores up to a total of 3 points in each of the following 3 parts: weight loss, changes in the underlying disease, and QoL. Each section is scored and totaled, and deductions are made from the total score in case of complications or re-operation. When calculating changes in the underlying disease, diabetes and high blood pressure (BP) were considered to be resolved when HbA1c and BP levels were maintained within the normal range (HbA1c <6.5%, BP <140/90 mmHg) despite the discontinuation of the drug being administered during the follow-up period and improved if the drug was reduced [19]. Readmission within 30 days of surgery was defined as a complication. Discharge within 7 days after readmission with only conservative management was defined as a minor complication, while hospitalization for more than 7 days with or without intervention was defined as a major complication. The system classified the outcome into one of 5 groups according to the final score: failure ≤1 point, fair=1–3 points, good=3–5 points, very good=5–7 points, and excellent=7–9 points [18].

3. Statistical analysis

The collected clinical data were analyzed using IBM SPSS version 28.0 (SPSS Inc., Chicago, IL, USA). Continuous variables are expressed as mean ± standard deviation, and Student’s t-tests were performed for each independent variable. Categorical variables were expressed as numbers (%), and the analysis was carried out using Fisher’s exact test. In a comparison of the total FTS and BAROS scores between the 2 groups, a P value of less than 0.05 was considered statistically significant.

RESULTS

In total, 580 patients underwent primary LSG during the study period. Among them, 159 patients who visited the outpatient clinic 1 year after surgery and adequately answered the FTS and BAROS questionnaires were included. When the patients were divided into 2 groups based on the 20% TWL cutoff 1 year after LSG, 17 patients were classified as STWL (%TWL ≤20) and 142 patients as OTWL (%TWL >20) (Fig. 1).

Fig. 1. Flow diagram of the study.

%TWL=(Initial Weight−Postoperative Weight)×100/Initial Weight.

LSG = laparoscopic sleeve gastrectomy, FTS = food tolerance score, BAROS = Bariatric Analysis and Reporting Outcome System, STWL = suboptimal total weight loss, OTWL = optimal total weight loss, %TWL = percent total weight loss.

The average preoperative weight of the patients was 106.77±19.63 kg, and the mean body mass index (BMI) was 38.98±6.35 kg/m². The proportions of females in STWL and OTWL were 82.35% and 79.58%, respectively, and the preoperative mean BMI was 36.54±5.06 and 39.27±6.44 kg/m², respectively. Even though there was no significant difference in height, weight, BMI, and sex between the 2 groups, patients in STWL were significantly older than OTWL (42.24±9.28 vs. 35.92±8.71 years old, P=0.006) (Table 1).

Table 1. Patient demographics.

Patient characteristics		Total patients (n=159)	STWL ≤20% (n=17)	OTWL >20% (n=142)	P value (STWL vs. OTWL)
Age (years)		36.60±8.96	42.24±9.28	35.92±8.71	0.006
Sex					1.000
	Male	32 (20.13)	3 (17.65)	29 (20.42)
	Female	127 (79.87)	14 (82.35)	113 (79.58)
Body weight (kg)		106.77±19.63	98.34±17.21	107.78±19.71	0.061
Height (cm)		165.38±8.17	163.80±9.00	165.57±8.08	0.401
Preoperative BMI (kg/m2)		38.98±6.35	36.54±5.06	39.27±6.44	0.093
Comorbidities
	Hypertension	68 (42.8)	7 (41.2)	61 (43.0)
	Diabetes	41 (25.8)	8 (47.1)	33 (23.2)

Data are presented as mean ± standard deviation or number (%). P values refer to the results of Student’s t-test or Fisher’s exact test.

%TWL=(Initial Weight−Postoperative Weight)×100/Initial Weight.

STWL = suboptimal total weight loss, OTWL = optimal total weight loss, BMI = body mass index, %TWL = percent total weight loss.

As shown in Table 2, 159 patients who underwent LSG experienced approximately 30.53±8.03% of TWL after one year after surgery. The complete and partial remission rates of hypertension and diabetes in all patients were 92.6% and 92.7%, respectively. Hypertension and diabetes were improved or resolved in all patients in the STWL group, and in 91.8% and 90.9% of patients in the OTWL group, respectively (Table 2).

Table 2. Surgical outcomes 1 year after laparoscopic sleeve gastrectomy.

Surgical outcomes		Total patients (n=159)	STWL ≤20% (n=17)	OTWL >20% (n=142)	P value (STWL vs. OTWL)
%TWL		30.53±8.03	17.28±2.60	32.11±6.91	<0.001
Hypertension		68	7	61	0.197
	Not improved	5 (7.4)	0	5 (8.2)
	Improved	13 (19.1)	3 (42.9)	10 (16.4)
	Resolved	50 (73.5)	4 (57.1)	46 (75.4)
Diabetes		41	8	33	0.560
	Not improved	3 (7.3)	0	3 (9.1)
	Improved	10 (24.4)	3 (37.5)	7 (21.2)
	Resolved	28 (68.3)	5 (62.5)	23 (69.7)

Data are presented as mean ± standard deviation or number (%). P values refer to the results of Student’s t-test or Fisher’s exact test.

%TWL=(Initial Weight−Postoperative Weight)×100/Initial Weight.

STWL = suboptimal total weight loss, OTWL = optimal total weight loss, %TWL = percent total weight loss.

The total FTS (1–30 points) for both groups was 25.02±3.16. The FTS for STWL and OTWL were 24.88±3.43 and 25.04±3.14, respectively, and there was no significant difference between the 2 groups (P=0.845). There was also no significant difference between the 2 groups in satisfaction with current eating, specific food tolerance, and vomiting or reflux scores, which are the sub-parameters of FTS (Table 3).

Table 3. FTS.

FTS parameters	Total patients (n=159)	STWL ≤20% (n=17)	OTWL >20% (n=142)	P value (STWL vs. OTWL)
Satisfaction with current eating (1–5 points)	4.01±0.86	4.06±0.83	4.01±0.86	0.815
Specific food tolerance (0–16 points)	13.34±2.30	13.12±2.42	13.37±2.30	0.675
Vomiting/Reflux score (0–9 points)	7.62±1.70	7.71±1.45	7.61±1.74	0.826
Total FTS (1–30 points)	25.02±3.16	24.88±3.43	25.04±3.14	0.845

Data are presented as mean ± standard deviation. P values refer to the results of the Student’s t-test.

%TWL=(Initial Weight−Postoperative Weight)×100/Initial Weight.

FTS = food tolerance score, STWL = suboptimal total weight loss, OTWL = optimal total weight loss, %TWL = percent total weight loss.

The total BAROS (maximum: 9 points) score was 5.96±1.48 in STWL and 7.20±1.40 in OTWL, confirming a statistically significant difference between the 2 groups (P<0.001). However, there were no significant differences in the medical conditions, QoL questionnaires, or complications. A total of 11 patients were readmitted within 30 days after LSG: 1 patient with STWL (5.88%) and 10 patients with OTWL (7.04%). The patients were discharged within 7 days with only supportive care. No major complications were observed. Only one patient with OTWL underwent reoperation due to surgical site infection and incisional hernia (Table 4).

Table 4. BAROS score.

BAROS parameters		Total patients (n=159)	STWL ≤20% (n=17)	OTWL >20% (n=142)	P value (STWL vs. OTWL)
Weight loss % of excess (−1–3 points)		2.43±0.67	1.47±0.52	2.53±0.60	<0.001
Medical conditions (−1–3 points)		2.76±0.76	2.53±1.01	2.79±0.72	0.892
QoL questionnaire (−3–3 points)		1.88±0.85	1.91±0.75	1.89±0.86	0.721
Complications		11 (6.92)	1 (5.88)	10 (7.04)	0.860
	Minor (−0.2 point)	11 (6.92)	1 (5.88)	10 (7.04)
	Major (−1 point)	0	0	0
	Reoperation (−1 point)	1	0	1
BAROS total score		7.05±1.48	5.96±1.48	7.20±1.40	<0.001

Data are presented as mean ± standard deviation. P values refer to the results of the Student’s t-test.

%TWL=(Initial Weight−Postoperative Weight)×100/Initial Weight.

Medical conditions: changes in underlying disease.

Outcome groups scoring: failure=1 point or less; fair=1 to 3 points; good=3 to 5 points; very good=5 to 7 points; excellent=7 to 9 points.

BAROS = Bariatric Analysis and Reporting Outcome System, STWL = suboptimal total weight loss, OTWL = optimal total weight loss, QoL= quality of life, %TWL = percent total weight loss.

DISCUSSION

In the short-term follow-up, effective weight loss after LSG has been reported; however, the problem of weight regain in the long-term follow-up has been reported in many studies [20,21,22]. Berry et al. [21] followed patients with a BMI of 30–35 kg/m² who underwent LSG for 3 years. Weight loss after 1, 2, and 3 years was 28.2%, 24.3%, and 22.1%, respectively, and weight regain was confirmed in this study. Another study group included 148 patients who underwent LSG 7 years after surgery. Weight loss after 1, 3, 5, and 7 years after surgery was 27.2%, 23.3%, 20.4%, and 16.3%, respectively, and weight regain was gradually confirmed during long-term follow-up [22].

However, Fiorani et al. [23] showed slightly different results from those of previous studies. Forty-three patients who underwent RYGB or LSG were followed up for 8 years after surgery. One year after surgery, weight loss in each group was 17.2% and 15.7%, respectively, with no significant difference between the 2 groups. After 8 years, weight loss was 29.2% and 27.7%, respectively, without weight regain nor a significant difference between the 2 groups. This study started with a small number of patients at the beginning, and many patients were lost to follow-up. Therefore, patients who were followed for a long period with high compliance were expected to have this result because of their strong willingness to undergo treatment. In our study, a total of 159 patients who underwent LSG experienced approximately 30.53±8.03% of TWL 1 year after surgery, which was in line with other studies with TWL from 15.7% to 31.3% [20,21,22,23]. However, since our study did not include long-term follow-up data, further studies should be conducted to assess the efficacy of LSG in weight loss.

The degree to which hypertension and type 2 diabetes, the main chronic diseases that accompany severe obesity after surgery, are improved or resolved reaches 50.0–99.9% for 0–79.16% for hypertension [21,23,24,25] and diabetes [20,21,23,24,25,26]. In general, diabetes has been found to have a higher rate of complete remission or improvement than hypertension. In our study, the improvement and remission rates of hypertension and diabetes were similar, at 91.8% and 90.9%, respectively. Contrary to our expectation, the rate of complete remission or improvement for hypertension and diabetes was higher in STWL than in OTWL, which is considered a good response to sleeve gastrectomy (SG). However, the complete remission or improvement rate exceeds 90% even in OTWL, where the number of patients with comorbidities is much higher. There is also no statistical difference between the 2 groups (P value for hypertension=0.197 vs. diabetes=0.560), suggesting that the comorbidities were highly improved even in patients who did not lose enough body weight after SG.

It is thought that patients with a higher BMI have more body fat. Thus, they may lose more weight after surgery. Park and Kim [27] divided 192 patients who underwent SG surgery into 2 groups based on a BMI of 35 kg/m² and followed up for 2 years. However, the percentages of excess weight loss in the lower BMI group (n=49) and the higher BMI group (n=143) were 86.1% and 61.9%, respectively, with higher weight loss observed in the lower BMI group. In this study, STWL was associated with a lower preoperative BMI, as shown in Table 1. However, because there was no statistical significance, the association between the preoperative BMI and %TWL could not be proven. As %TWL is one of the major factors in total BAROS, more studies are needed on the effects of preoperative BMI on BAROS.

FTS scores are usually high unless severe postoperative complications, such as anorexia nervosa, cause problems with dietary progression. According to D’Hondt et al. [12], the FTS score of 83 non-obese healthy individuals was 24.9, which was higher than the score of 23.8 for patients who underwent SG for obesity. Kafri et al. [28] studied 60 patients who underwent SG surgery by dividing them into 2 groups: less than one year of follow-up (n=35) and >1 year of follow-up (n=25). The FTS scores of the groups were 17.6±5.0 and 22.7±3.0, respectively, showing a gradual improvement after surgery. In this study, we expected that each FTS parameter would be higher in patients with STWL. However, as Table 3 confirmed, there was no significant difference between the 2 groups in our study, possibly because the FTS takes the form of a survey, and the first parameter, satisfaction with current eating, is subjective. Patients with significant weight loss may have perceived this phenomenon to be a normal part of weight loss, even if they had problems, such as sleeve stricture or torsion, and their diet was somewhat distorted.

BAROS is used to comprehensively assess changes in medical status and QoL after bariatric surgery [18]. In a study of 43 patients who underwent LRYGB and LSG, Fiorani et al. [23] reported that BAROS scores were not statistically different between the 2 groups, with an average of 3.49±0.24 and 3.49±0.51 (BAROS outcome: good), respectively, one year after surgery. These results are lower than the overall average of 7.05±1.48 (BAROS outcome: excellent) in our study. In the study by Kirkil et al. [26], among 562 patients who underwent LSG, patients with a follow-up period of 9–12 months had an average of 5.2±2.1 (BAROS outcome: very good), which is also lower than our study result. Of the patients, 19.93% also had poor results, such as failure or fair. In a study by Sofianos et al. [29], a total of 103 patients who underwent LSG had an average of 5.1 in BAROS, and 3.9% of total patients were categorized as failure or fair (BAROS total score <3). In our study, only one patient (0.63%) who underwent reoperation was classifiable under failure or fair. Regardless of weight loss, both groups showed good QoL questionnaire scores with no significant differences between the groups. The total BAROS levels were significantly higher in OTWL (Table 4). However, the only variable that differed between the 2 groups was weight loss, and there was no difference between the other variables. Scores are given according to the degree of weight loss in BAROS. Because the patients were classified according to the amount of weight loss, a difference in the total BAROS score was expected.

This study had some limitations. Less than 30 patients were selected and placed in STWL (n=17). After the normality test, we conducted Student’s t-test, assuming that the patients showed normality. However, the lack of a sufficient number of patients could be a limitation. In addition, although there are previous studies on gradual weight regain one year after LSG [12,20,21,22], the results of this study do not reflect changes in BAROS scores in the mid- to long-term. Finally, only about 159 out of 580 patients were able to follow up for one year, and about 70% of patients were lost. Thus, attrition bias may be a problem in this study. During the study period, the global epidemic of coronavirus disease 2019 (COVID-19) spread rapidly, and the domestic situation was poor. According to the global distribution of COVID-19 confirmed cases [30], the number of confirmed cases in South Korea was 5.3% of the worldwide confirmed cases, which made it the third-highest number of confirmed cases outside of China. Because there were some restrictions on access in particular areas, such as public institutions and hospitals, the proportion of follow-up patients may have been small. Alternatively, attrition may also be likely if the patients were doing well and had no problems after surgery or if they failed to lose weight but otherwise had no complications.

In conclusion, although total BAROS was significantly higher in OTWL with substantial weight loss, there was no significant difference in other variables, such as medical conditions, QoL, and complications. There was no difference in postoperative satisfaction and QoL between STWL and OTWL after LSG, except for the degree of weight loss.