An interventional study of Low-Cost Post-Bariatric Diet and Standard High-cost Post-Bariatric Diet in Obesity, Bariatric Surgery and Nutritional Status, sponsored by Khyber Teaching Hospital. Not yet recruiting at 1 site in Pakistan. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2025-08-08.
Sponsored by Khyber Teaching Hospital · Not applicable, Interventional, and Treatment
This study will see if a low-cost dietary plan, based on the standard dietary guidelines of the American Society for Metabolic and Bariatric Surgery (ASMBS) and using locally available foods, can help patients lose weight and keep their lean body mass after bariatric surgery. It will also check if this plan can maintain healthy levels of important nutrients such as vitamin B12, iron, and vitamin D.
Patients who have undergone bariatric surgery will be randomly assigned to follow either the low-cost diet or the regular hospital diet. Their weight, body composition, and nutrient levels will be tracked at baseline, and at 1, 3, and 6 months after surgery.
The aim is to find out if this simpler, affordable diet, which follows international standards, works as well as the regular plan while being easier for low-income patients to follow.
Obesity is a growing global health problem and is recognized by the World Health Organization (WHO) as a leading cause of preventable disease. It is a complex, long-term condition influenced by multiple factors, and treatment options range from lifestyle changes to medications and surgery. Bariatric surgery is currently the most effective long-term treatment for morbid obesity. It not only helps in significant weight loss but also improves obesity-related health problems such as type II diabetes, hypertension, and obstructive sleep apnea, while improving quality of life.
Among the various surgical techniques, Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), and one-anastomosis gastric bypass (OAGB/MGB) are the most commonly performed. However, these surgeries can lead to reduced absorption of essential nutrients because they bypass parts of the intestine where vitamins and minerals are absorbed. Nutrient deficiencies, particularly in vitamin B12, iron, and vitamin D, are common after bariatric surgery. Therefore, structured dietary management and supplementation are essential after surgery to prevent these deficiencies and preserve lean body mass (LBM).
Standard dietary recommendations from the American Society for Metabolic and Bariatric Surgery (ASMBS) suggest a gradual progression from liquids to solid foods, adequate protein intake (1.0-1.5 g/kg), and lifelong use of vitamin and mineral supplements. However, in countries like Pakistan, where 45% of the population lives below the international poverty line, the standard postoperative diet often includes costly imported supplements like whey protein, which are unaffordable and hard to access for most patients, particularly those from rural areas. This creates barriers to dietary compliance and worsens clinical outcomes.
Adequate protein intake plays a key role in preserving lean body mass and improving recovery after bariatric surgery. Nutritional deficiencies, particularly in vitamin B12, iron, and vitamin D, remain prevalent after bariatric surgery and require targeted nutritional strategies.
In response to these challenges, this study introduces a low-cost dietary plan based on ASMBS guidelines using locally available, affordable foods to meet protein and micronutrient needs. It aims to compare this plan with the conventional high-cost hospital diet to determine whether it can effectively promote weight loss, maintain lean body mass, and prevent micronutrient deficiencies. By aligning with international standards while addressing local socioeconomic constraints, this approach could improve patient adherence, nutritional outcomes, and overall recovery following bariatric surgery.
6,296 studies on the registry are indexed under Obesity; 1,692 are open to participants now.
This study's planned enrollment of 122 is above the median of 78 across 4,878 interventional studies indexed under Obesity.
Browse Obesity studies →Khyber Teaching Hospital is the lead sponsor of 28 studies on the registry; 18 are open to participants now.
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Exclusion Criteria:
Participants in this arm will follow a low-cost dietary plan designed according to the American Society for Metabolic and Bariatric Surgery (ASMBS) guidelines, using locally available, affordable foods to meet protein and micronutrient needs. The plan aims to promote weight loss, preserve lean body mass, and prevent nutrient deficiencies.
Dietary Supplement: Low-Cost Post-Bariatric Diet
Participants in this arm will follow the standard postoperative hospital diet, which includes expensive protein supplements (e.g., whey protein, cottage cheese) and imported nutritional products typically recommended after bariatric surgery.
Dietary Supplement: Standard High-cost Post-Bariatric Diet
Low-Cost Post-Bariatric Diet (Experimental): Based on the American Society for Metabolic and Bariatric Surgery (ASMBS) guidelines. Uses affordable, locally available foods (e.g., eggs, lentils, local dairy products) to meet protein and micronutrient needs. Designed to be cost-effective and accessible for patients from low-income or rural areas.
Standard Post-Bariatric Diet (Active Comparator): The conventional high-cost diet currently followed at the study hospital. Includes imported or expensive protein supplements such as whey protein and cottage cheese, along with nutritional products not easily accessible in rural or low-resource settings.
Weight Loss
Weight loss will be measured using a calibrated digital weighing scale.Weight loss will be defined as the reduction in body weight (kg) from baseline. Unit of Measure: Kilograms (kg)
Time frame: Baseline, 1 month, 3 months, and 6 months after surgery.
Change in Serum Iron Levels
Hemoglobin (g/dL) and serum ferritin (ng/mL) measured via blood tests.Iron deficiency will be defined as Hb \<12 g/dL (women) or \<13 g/dL (men) and/or ferritin \<15 ng/mL.
Time frame: Baseline, 1 month, 3 months, and 6 months post-surgery.
Change in Serum Vitamin B12 Levels
Measured via serum vitamin B12 assay.Levels below 200 pg/mL will be considered deficient.
Time frame: Baseline, 1 month, 3 months, and 6 months post-surgery.
Change in Serum Vitamin D Levels
Serum 25(OH) vitamin D (ng/mL) measured via blood assay . Levels below 20 ng/mL will be considered deficient.
Time frame: Baseline, 1 months, 3 months, and 6 months post-surgery.
Lean Body Mass (LBM)
Change in lean body mass assessed using bioelectrical impedance analysis to evaluate preservation of lean tissue after bariatric surgery. Unit of Measure: Kilograms (kg)
Time frame: Baseline, 1 month, 3 months, and 6 months postoperatively
Body Mass Index (BMI)
BMI will be calculated by dividing weight (kg) by height squared (m²). Height will be measured only at baseline, as it remains unchanged postoperatively. Follow-up BMI will be derived using baseline height and follow-up weight measurements.Unit of Measure: kg/m²
Time frame: Baseline, 1 month, 3 months, and 6 months postoperatively
Plan to share: No
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Khyber Teaching Hospital