The Relationship Between Diet of Adolescents Before Sleeve Gastrectomy and Success with Weight Loss and Behavioral Changes Six Months Postsurgery

Abstract

Background:

Bariatric surgery is becoming more common for adolescents. This study aims to describe presurgery dietary intake in adolescents who underwent sleeve gastrectomy to determine whether there is a correlation between fruit and vegetable intake before surgery and weight loss, physical activity, and psychological measures postsurgery.

Methods:

Adolescents between 13 and 17 years old with a body–mass index (BMI) between 35 and 60 kg/m² who received the sleeve gastrectomy procedure were recruited for the study. Weekly servings of fruits and vegetables reported during the initial consultation were collected and analyzed.

Results:

Mean age of participants (n = 13) was 16.8 years. We observed a moderate positive relationship between combined fruit and vegetable consumption (r = −0.60, p = 0.01) and particularly with fruit consumption alone (r = −0.66, p = 0.0003) with change in BMI at 6 months after surgery. There was also a significant positive relationship between combined fruit and vegetable intake and changes in appetite awareness 6 months postsurgery (r = 0.41, p = 0.05).

Conclusions:

This was the first study to examine the correlation between presurgical diet and weight loss postsurgery in adolescents. Dietary factors such as higher consumption of fruits and vegetables before surgery may help improve hunger/fullness awareness postsurgery.

Introduction

The rate of surgical weight loss procedures in adolescents has tripled between 2000 and 2003 to an estimated 770 procedures nationwide.¹ In a survey of bariatric surgeons in the United States in 2005, 75% reported that they were planning to perform the procedure on an adolescent in the upcoming year, while 42% reported that they were in the process of developing a multidisciplinary adolescent weight loss surgery program at their center.¹

Childhood and adolescent overweight and obesity has more than tripled over the past two decades.² Some pediatric studies have reported that bariatric surgery is a more effective weight loss method than diet supervision and counseling for obese youth who have comorbidities.³ Although bariatric surgery is becoming more common for adolescents, evidence-based postoperative nutritional guidelines have yet to be published.⁴ Currently, there are few studies that describe outcomes after bariatric surgery in adolescents or nutrition behaviors that predict weight loss postsurgery. The few studies that have analyzed predictors of success in adolescents undergoing bariatric surgery have identified increased physical activity and more frequent nutritional counseling as variables that aid in successful weight loss.^5,6 Widhalm et al. reported that patients with a mean age of 17.7 ± 2.6 years who underwent the gastric banding procedure regained much of their weight at a 48-month follow-up. Despite the limited ability to consume large amounts of food after surgery, dietary records revealed that patients had readopted habits of drinking greater amounts of high calorie beverages and more calorie-dense foods, leading to weight regain.⁶ This observation is not surprising given that it has been found that adolescents who consume more sugar-sweetened beverages have higher body weight compared with those who drink fewer.⁷ These findings are just one example of why more emphasis needs to be placed on dietary habits before and after a bariatric procedure.

While the use of bariatric surgery for adolescents has become more common (Roux-en Y, gastric band, sleeve gastrectomy), sleeve gastrectomy has become a more widely used method for adolescents in recent years, increasing in prevalence from 6.7% in 2008 to 24% in 2011.⁸ With the rate of severe obesity (body–mass index [BMI] ≥40 kg/m²) rising in children in the United States to an estimated 4% to 6%,⁹ it is imperative to find solutions that will encourage sustained weight loss in this population.

While evidence-based guidelines have yet to be published for adolescents who undergo bariatric surgery, the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) and The National Association of Children's Hospitals and Related Institutions (NACHRI) published nutritional recommendations in 2011. These organizations recommended that a preoperative nutritional assessment be completed for all patients planning to have bariatric surgery. During this assessment, patients should undergo a nutritional evaluation, which includes selective micronutrient needs as well as identifying nutritional and educational needs. It is also suggested that a food frequency/eating behavior questionnaire be completed by the patient to provide more insight on current personal nutritional practices. During the preoperative phase, a healthy balanced diet consisting of adequate protein, fruits, vegetables, and whole grains is recommended to encourage weight stabilization or weight loss. In the postoperative phase, the NASPGHAN and NACHRI recommend a diet progression for gastric sleeve patients occurring in five stages. Daily recommendations for Stage 5, which begins at 9 weeks, should be followed for life and include a total of 800–900 calories, 60 g of protein, and 80–90 oz. (or based on estimated requirements) of fluids. At this time, new foods should be introduced, including all healthy food choices with a meal pattern of three to six meals per day and a volume up to ¾ to 1 ½ cup per meal.⁴

Today in the United States, less than 20% of youth consume fruits and vegetables to meet national dietary guidelines.^10,11 Adolescents reportedly consume the majority of fruit from fruit juices rather than whole fruits, while the majority of vegetable intake for adolescence seems to be coming more from white potatoes than from green, yellow, and orange vegetables. Adolescents who consume high amounts of energy from fast food have been found to be less likely to meet recommended intake for fruits.¹² Lorson et al. examined correlates of fruit and vegetable intake in children and adolescence in the United States between 1999 and 2002 using NHANES data and found that ∼28% of reported vegetable intake by adolescents came from French fries, while 38% of total fruit intake came from fruit juice.¹¹ Furthermore, the study found that overweight children and adolescents consumed less total fruit and more French fries than those who were normal weight or at risk overweight.¹¹ The Dietary Guidelines for Americans 2010 recommend that people should choose whole or cut up fruits, which are not as calorie dense, more often than fruit juice, which contains more calories per gram.⁷

The objectives of this study are (1) to describe fruit and vegetable intake in adolescents who underwent sleeve gastrectomy between 2011 and 2013 at a pediatric healthy weight clinic and (2) to determine whether there is a correlation between fruit and vegetable intake before surgery and weight loss postsurgery.

Methods

Participants

The participants in this study received the sleeve gastrectomy procedure. Inclusion criteria for the study included that patients had to meet the Pediatric Healthy Weight Clinic criteria for eligibility.

The patient must have a BMI of 40 kg/m², or a BMI of 35 kg/m² with comorbidity, and be between 13 and 20 years of age (inclusive). If it is determined that the patient is eligible for surgery, the clinic protocol requires that they are counseled by the interdisciplinary team, which is made up of a dietitian, pediatrician, psychologist, nurse, and exercise physiologist. The patient must be approved by all team members as being ready for surgery to receive the bariatric surgery. Important considerations that are monitored include the ability to comply with postsurgery diet, psychological readiness, and physical ability to undergo surgery. To have surgery, patients must be seen and evaluated by the entire team for a minimum of 6 months to optimize results after sleeve gastrectomy.

Research design

This study was a retrospective chart review in collaboration with the Health4Life Clinic at Children's Healthcare of Atlanta. The medical records of patients who underwent bariatric surgery between 2011 and 2013 and were under the supervision of the clinic for at least 1 year were reviewed and analyzed. Institutional Review Board (IRB) approval was obtained from both Emory University and Georgia State University.

Demographic variables included date of birth, age, gender, and race. Other variables collected at baseline, 1–3 months postsurgery, and 6 months postsurgery included height (cm), weight (kg), calculated BMI (kg/m²), measures of hunger/fullness awareness, general food cravings, and depressive symptoms, waist circumference, and physical activity (minutes per week). Weight and height were collected during visits to the clinic by the same nurse each time. Weekly number of cups of fruits and vegetables, cups of sweetened beverages (separated as fruit juice or soda), cups of fried foods eaten, and meals eaten from or at restaurants as reported at the initial consultation were extracted from the initial nutrition assessment form and analyzed. Dietary recalls were conducted by a registered dietitian (RD) during the initial nutrition assessment using a dietary recall and food frequency questionnaire along with food and portion size models to determine exact servings of food and beverages consumed. Measures of hunger/fullness, food cravings, and depression were administered by the same psychologist. Hunger/fullness awareness was measured using the Appetite Awareness Scale for Children (AAS-C), which is a six-item measure of children's perceived sensitivity to their internal appetite cues.¹³ A modified version of the Trait and State Food Cravings Questionnaire¹⁴ was used to assess as a general index of food cravings (MGFCQ). The 21-item modified form was used to assess cravings for a variety rather than specific foods. This questionnaire used the Likert scale ranging from 1 to 6, indicating the degree to which each statement would be true for the patient (1 = never or not applicable, 6 = always).¹⁵ Depression scores were measured using Quick Inventory of Depressive Symptomatology-Self-Report-16 (QIDS-SR16), a nine-item measure of physiological and psychological depressive symptoms.¹⁶ Minutes of physical activity (PA) per week were self-reported by the patient and collected by the same exercise physiologist at each clinic visit.

Statistical analysis

All statistical analyses were conducted using SPSS (version 21.0; SPSS, Inc., Chicago, IL). The demographic and anthropometric characteristics of the population were described using frequency statistics. Kendall's tau rank correlation was used to analyze relationships between initial weight, changes in weight, waist circumference, reported weekly minutes of physical activity, AAS-C, MGFCQ, and QIDS scores with baseline fruit and vegetable intake and baseline sweetened beverage intake. A p-value of <0.05 was considered significant.

Results

Data from 13 patients were reviewed and collected. Two patients were subsequently excluded from the results analysis for 6-month follow-up measures due to follow-up time being less than 6 months. Data were, however, analyzed on all 13 patients for baseline and 1- to 3-month follow-up measures. The demographic and anthropometric characteristics of the population are shown in Tables 1 and 2. The mean age of participants was 16.8 ± 0.9 years. Average follow-up times were 1.5 and 7.5 months. Mean follow-up weight was 129.23 ± 22.02 kg at 1 to 3 months and 117.65 ± 23.86 kg at 6 months; mean follow-up BMI was 46.7 ± 8.0 kg/m² at 1 to 3 months and 42.05 ± 8.3 kg/m² at 6 months.

Table 1.

Demographic Data of Participants

	n	%
Gender
Male	3	18.2
Female	10	81.8
Race
African American	6	54.5
Caucasian	5	45.5
BMI classification
Severely obese (BMI <50 kg/m²)	7	53.8
Superobese (BMI ≥50 kg/m²)	6	46.2

BMI, body–mass index.

Table 2.

Subject Baseline Characteristics

	Mean ± SD	Range
Age (years)	16.8 ± 0.9	13–19
Weight (kg)	41.1 ± 25.2	115.8–210.4
BMI (kg/m²)	50.7 ± 8.3	43.1–72.7
BMI z-score	2.73 ± 0.3	2.43–3.43
Vegetables/week^a	6.7 ± 3.9	2–14
Fruits/week	6.2 ± 3.9	1–14
Combined fruits and vegetables/week	12.9 ± 6.6	5.5–54.5
Sugar-sweetened beverages^b	8.2 ± 20.7	0–70
AAS-C score^c	16.1 ± 6.6	9–25
MGFCQ score^d	14.8 ± 3.3	9–19
QIDS score	6.1 ± 1.7	3–9
Exercise (min/week)^e	116.15 ± 88.3	0–275
Waist circumference (cm)	123.2 ± 12.5	104–150

All (n = 13).

Servings = 1/2 cup.

n = 11, 6 oz servings per day.

n = 8.

n = 9.

Physical activity = estimated minutes per week, self-reported.

AAS-C, Appetite Awareness Scale for Children; MGFCQ, modified version of the Trait and State Food Cravings Questionnaire; QIDS, Quick Inventory of Depressive Symptomatology.

We observed a moderate positive relationship between combined fruit and vegetable consumption (r = −0.60, p = 0.01) and particularly with fruit consumption alone (r = −0.66, p = 0.0003) with change in BMI at 6 months after surgery.

Changes in AAS-C, MGFCQ, and PA are reported in Table 3. A negative relationship was also found between sugar-sweetened beverage intake and decreases in AAS-C scores at 1 to 3 months (r = −0.72, p = 0.03) and 6 months after surgery (r = −0.57, p = 0.03) and with decreases in MGFCQ scores at 6 months (r = −0.65, p = 0.03). Although not significant, there was a positive relationship between vegetable intake and changes in AAS-C at 1–3 months postsurgery (r = 0.51, p = 0.09). This relationship was significant at 6 months postsurgery (r = 0.57, p = 0.010). A significant positive relationship between vegetable intake and changes in MGDFCQ was found at 6 months postsurgery (r = 0.53, r = 0.05). There was also a significant positive relationship between combined fruit and vegetable intake and changes in AAS-C 6 months postsurgery (r = 0.41, p = 0.05). In a post hoc analysis, severely obese patients at baseline consumed significantly fewer daily servings of sweetened beverages at baseline than superobese patients (0.5 ± 1.2 vs. 17.3 ± 29.7, p = 0.04). Severely obese patients also consumed more servings of fruits and vegetables than superobese patients (15.0 ± 7.0 vs. 10.4 ± 5.4) at baseline.

Table 3.

Changes in Body–Mass Index, Psychological Measures, and Exercise Measures Postsleeve Gastrectomy

	1–3 months	6 months
Change in BMI (kg/m²)^a	−3.9 ± 2.5^b	−14.8 ± 4.0^b
Change in AAS-C score^c	−7.0 ± 6.7^d	−0.8 ± 11.0^d
Change in MGFCQ score^e	−3.1 ± 5.0	−6.3 ± 2.7^f
Change in QIDS score^a	+0.2 ± 3.5	−1.4 ± 2.6
Change in exercise (minutes/week)^g	+14.0 ± 127.6	+115.0 ± 111.5^f
Change in waist circumference (cm)^e	−7.8 ± 5.2^f	−15.9 ± 8.4^b

Changes = (1–3 months–baseline); (6 months–baseline).

n = 13.

Significant changes p < 0.001.

n = 8.

Significant changes p < 0.05.

n = 9.

Significant changes p < 0.01.

n = 10.

PA was found to increase 1–3 months after surgery (+14 ± 115 min/week) and to significantly increase (+115 ± 111.5 min/week, p = 0.008) at 6 months.

Discussion

We found a moderate relationship between fruit and vegetable consumption before surgery and weight loss 6 months postsurgery in adolescent bariatric patients. Previous studies have shown that the greatest degree of relative weight loss occurs within the first 6 months after surgery.^17,18 A larger population sample may have revealed a more significant finding. Moreover, differences in dietary consumption may play a greater role in weight lost after a longer period of time postsurgery. Because weight loss was measured just 6 months after surgery, it may be important to consider that a longer time frame would reveal a stronger relationship between postsurgical weight loss with dietary patterns before surgery.

None of the participants in the study met the U.S. Dietary Guidelines for Americans for fruit or vegetable intake during their initial assessment. The guidelines recommend 2.5 cups of vegetables per day and 1.5 cups of fruit per day for adolescent females and 3 cups per day of vegetables and 2 cups per day of fruit for adolescent males.⁷

When BMI was stratified by weight class into severely obese and superobese; superobese patients consumed fewer cups of fruits and vegetables combined than severely obese at baseline. In a retrospective study, Christou et al. found that superobese patients lost weight more rapidly from baseline to lowest weight reached, but then regained weight more rapidly when compared with severely obese patients.³ These findings might suggest that if superobese patients have poorer dietary habits such as eating fewer fruits and vegetables, they may be more susceptible to weight regain after initial weight loss postsurgery.

Another study that examined dietary intake and weight loss 7 years after surgery in adults did find a relationship between dietary behaviors and weight lost. Cook et al. examined habits that led to successful weight loss maintenance in 100 gastric bypass patients an average of 7 years after surgery. Surveys were conducted in person, over the phone, or in writing. Successful weight loss was defined as maintaining at least 74% of initial weight loss. Results of the survey revealed that successful patients reported eating three servings of vegetables per day and one serving of fruit per day. Fifty-eight percent of successful patients also reported not drinking carbonated beverages of any kind and 55% reported not drinking any fruit juice or sweetened beverages. Seventy-seven percent of successful patients reported exercising an average of four times per week for at least 40 min.¹⁹ This longer follow-up time allowed for a more realistic look at how dietary factors effected weight loss maintenance over time. One weakness of this study was the use of self-reported dietary recall, which can overestimate adherence to dietary guidelines.

Our findings concluded that food cravings significantly decreased for patients at 6 months postsurgery. Patients who drank more sweetened beverages at baseline saw less improvement in hunger/fullness awareness and food cravings than those patients who drank less sweetened beverages at baseline. One animal study by Mitra et al. found that that chronic consumption of sugar blunted activity of pathways that mediate satiety. These finding suggests that a reduction in central satiety signaling precipitated by chronic consumption of high-sugar foods may lead to generalized overeating.²⁰ Furthermore, findings revealed that patients who consumed more fruits and vegetables at baseline experienced more improvements in hunger/fullness awareness and food cravings after surgery. This may be explained by considering that patients who already consumed fruits and vegetables, which are more nutrient dense and fiber rich, are more equipped to recognize hunger cues and fight cravings for unhealthy foods. One study examined changes in adult bariatric surgery patients' frequency of food cravings and consumption of craved foods from before surgery to 3 and 6 months after surgery and compared surgical patients' frequency of food cravings with those of normal weight who had not undergone surgery. Leahey et al. found that the bariatric patients had significant reductions in overall cravings for and consumption of craved foods, specifically for sweets and fast food. However, surgery had nearly no effect on the cravings for high-fat foods and the patients' postoperative weight loss was largely unrelated to food cravings.²¹

This review also revealed that physical activity increased 1–3 months after surgery and increased significantly from baseline by 6 months postsurgery. Previous studies have found that physical activity increases after bariatric surgery and that physical activity is associated with surgically induced weight loss.²² We did not, however, find any relationships between baseline dietary intake and physical activity postsurgery.

To date, there have been no studies that examine presurgical dietary behaviors that may lead to successful weight loss maintenance in adolescents who undergo bariatric surgery. Conclusive data in this area will assist in creating evidence-based nutritional guidelines for this population. Our study analyzed dietary intake from an initial clinic visit. Examining multiple dietary recalls to identify changes in dietary habits over time may have been valuable for this study. It is unknown what dietary changes these patients made leading up to surgery and after surgery. It would be expected that some nutritional changes were made before surgery as these patients visited with an RD multiple times before having surgery. Additionally, patients are required to demonstrate that they can maintain weight or lose weight before surgery, suggesting that nutritional changes were implemented. Future studies that analyze initial dietary recalls along with subsequent dietary recalls would provide more conclusive evidence about how initial dietary habits affect the ability to make dietary changes, successfully lose weight, and maintain weight loss.

It is not fully understood which dietary habits are easier to adopt for obese adolescents. For example, it may be easier to decrease consumption of calorie-dense foods if the adolescent also enjoys less calorie-dense foods such as fruits and vegetables. It may be more difficult to avoid foods that contribute to weight gain if the adolescents are not able to replace these foods with healthier options they already consume. Eliminating foods they enjoy while introducing foods they do not enjoy may pose an additional obstacle for long-term dietary changes and thus may lead to a decreased opportunity for long-term weight loss maintenance. There are currently no studies to our knowledge that explore this possibility; this may be an area of interest that will help to understand dietary predictors of success in adolescents who undergo bariatric surgery. While it has been shown that an overall reduction in energy consumption favors an ideal body weight,²³ few studies have been able to identify individual components of dietary composition that determine success in weight loss or favor an ideal body weight for bariatric patients, particularly in adolescents. For this reason, this study focused on baseline dietary behaviors.

This study has several limitations. A longer study is needed to determine the effects of dietary behaviors on weight loss, maintenance, and regain after bariatric surgery among adolescents. Research has shown that there is an increased risk for weight regain in bariatric patients at 2 to 5 years postsurgery.³ Thus, following up with the patient population longer than 6 months postsurgery may more realistically reflect how dietary behaviors affect their long-term weight loss outcomes. Our small sample size is another limitation of this study. Because bariatric surgery is not as common as bariatric surgery in adults, we had a limited sample size of patients who qualified for the study. Dietary recalls were only considered from an initial assessment and there were no data on changes in dietary behavior leading up to surgery or postsurgery.

Conclusions

A clear relationship between dietary intake of fruits and vegetables before surgery and weight loss after surgery has yet to be determined. Dietary factors such as higher consumption of fruits and vegetables before surgery may help improve hunger/fullness awareness and food cravings after surgery, which may ultimately lead to a higher rate of sustained weight loss. Conversely, a higher baseline intake of sugar-sweetened beverages may negatively affect patients' hunger/fullness awareness postsurgery. This was the first study that examined a relationship between dietary intake before bariatric surgery and weight loss, hunger/fullness awareness, food cravings, and depression after surgery in adolescents. The current study provides direction for future research on this topic. The decision to pursue bariatric surgery for the treatment of obesity is a challenging decision for adolescents and their families. Finding nutritional strategies to promote weight loss maintenance after bariatric surgery is imperative to ensure optimal outcomes for adolescents.

Footnotes

Acknowledgment

The authors would like to acknowledge the Strong4Life Clinic at Children's Healthcare of Atlanta for their support of this research.

Author Disclosure Statement

No competing financial interests exist.

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