# Mechanisms that Predict Weight Trajectory after Bariatric Surgery: The Interactive Roles of Behavior and Biology

> **NIH NIH R01** · NORTH DAKOTA STATE UNIVERSITY · 2020 · $930,251

## Abstract

Abstract
Bariatric surgery is currently the most efficacious and durable intervention for severe obesity.
Many comorbid conditions (e.g., diabetes, hypertension) generally remit or resolve following
bariatric surgery. Yet, some patients experience suboptimal weight outcomes following surgery,
often resulting from substantial weight regain following successful weight loss. Unfortunately,
weight recidivism is also often associated with reemergence of obesity-associated
comorbidities. The most commonly performed procedures in the U.S. are the Roux-en-Y
Gastric Bypass (RYGB) and the laparoscopic Sleeve Gastrectomy (SG). Both procedures
involve significant anatomical and physiological changes that lead to changes in behavior and
biology. The etiological contributors to weight loss following surgery are not well understood,
and it is therefore difficult to predict which patients may experience suboptimal post-surgical
weight outcomes. Changes in eating and physical activity behaviors, mood, and the
microbiome have all been reported to occur following bariatric surgery and have an association
with weight change. Weight change likely involves complex interactions between behavioral
and biological variables. The longitudinal relationship between changes in the gut microbiome
and post-surgery weight trajectory has not been explored thoroughly, and the associations
between the microbiome and other variables that impact weight have been similarly
understudied. Therefore, we propose to conduct a prospective, 24-month longitudinal study of
patients planning to undergo RYGB or SG and aim to identify correlates and predictors of
observed weight loss trajectories over 24 months following bariatric surgery. In particular, this
application is designed to examine the relationships between empirically supported behavioral
and biological variables following surgery and their combined impact on weight outcome. These
data will extend the current literature by collecting behavioral and biological data, by carrying out
longer term follow-up of participants enrolled, and by studying a larger sample size. Novel data
collection in this protocol will include intensive measurement of problematic eating behaviors
and compliance with diet and exercise regimens post-surgically, which may be altered in parallel
with, or in response to, changes observed in the gut microbiota. Identifying post-surgical
predictors of weight loss and comorbidity resolution will allow for the development of
interventions that can be tailored to individual patients based upon his/her risk profile which can
then be implemented early to optimize surgery-related outcomes.

## Key facts

- **NIH application ID:** 9997908
- **Project number:** 5R01DK112585-05
- **Recipient organization:** NORTH DAKOTA STATE UNIVERSITY
- **Principal Investigator:** Leslie J. Heinberg
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $930,251
- **Award type:** 5
- **Project period:** 2016-09-15 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9997908

## Citation

> US National Institutes of Health, RePORTER application 9997908, Mechanisms that Predict Weight Trajectory after Bariatric Surgery: The Interactive Roles of Behavior and Biology (5R01DK112585-05). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9997908. Licensed CC0.

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