Nutrition’s Role in Patient Outcomes

Perioperative optimization of nutrition leads to lower risks, better outcomes, and improved quality of life for adult patients undergoing metabolic and bariatric surgery, according to an updated clinical practice statement from the Obesity Medicine Association (OMA).

The update offers guidance on how to manage metabolic and bariatric surgery patients’ nutrition, from preoperative nutritional assessments through identification and treatment of the most common nutritional problems associated with bariatric procedures.

“The main takeaway really is that obesity is a complex and chronic disease. It requires the same model of care as diabetes or other chronic conditions,” said Rutuja Patel, DO, senior author and an obesity medicine specialist at Northwestern Medicine Regional Medical Group in Winfield, Illinois.

The development of an interdisciplinary team of medical providers with evidence-based nutrition knowledge and consistent information improves the quality of nutrition care provided to bariatric surgery patients, the authors wrote.

“Collaborative multidisciplinary care that takes into consideration the whole patient in a biopsychosocial way and uses multiple modalities — including medical, behavioral, nutritional, and others — leads to the best outcomes in these complex patients,” Patel said.

The updated statement, published online in the March Obesity Pillars, offers a variety of tools and checklists to aid clinicians, especially those who may not have access to a multidisciplinary team or dietitian knowledgeable about bariatric nutrition.

It is a follow-up to the OMA’s 2022 clinical practice statement, which provided an overview of bariatric surgery, gastrointestinal hormones, and the microbiome in patients with obesity.

Presurgical Guidance

The new guidance lays out the various components of preoperative nutrition screenings, among which is a medication review to determine if the patient is taking drugs that may affect weight and calorie intake. These include antihypertensives, diabetes agents, hormonal contraceptives, antidepressants, migraine medications, and antipsychotics.

In taking a patient’s history, clinicians should ask about major events associated with weight changes, such as medication changes, illness, pregnancy, divorce, stressful employment, food insecurity, and periods of disordered eating.

The fundamental to conducting a nutrition assessment is an understanding of the role that various sections of the gastrointestinal tract play in micronutrient absorption, the authors wrote. As an educational tool, the update includes a diagram that indicates the areas of the stomach, duodenum, jejunum, and ileum that may be altered by bariatric surgery and how they factor into micronutrient absorption.

“It makes it easier to see why certain surgical procedures are more likely to cause certain deficiencies,” Patel said.

Postsurgery Patient Management

Postsurgery, clinicians should monitor patients for other problems that could affect nutrient absorption, including food intolerances, drug-nutrient interactions, and increased gastrointestinal transit time.

Patel and coauthors discussed the pros and cons of multivitamin mineral supplement formulations as well as specific vitamin and mineral recommendations for patients undergoing certain metabolic or bariatric surgery procedures. They included three supplemental cases in the appendix to illustrate supplementation recommendations and long-term maintenance suggestions.

“It’s important to remember that most of these deficiencies present without many clinical symptoms, so it becomes essential to screen for them and repeat as needed,” Patel said.

The update also tackles postoperative nutritional assessments and diet progression. No evidence supports following one postsurgical diet progression protocol over another, but they generally proceed from a clear liquid diet to foods with normal textures, the authors noted. Clinicians should adapt them according to the procedure type, they added.

Additionally, clinicians must troubleshoot any nutrition-related concerns, including constipation, dehydration, nausea, heartburn, and fatigue, for up to a year after surgery, they wrote.

Metabolic and bariatric surgery patients should be evaluated annually at a minimum, if not more frequently, to gauge nutritional health, the authors wrote. Treating obesity as a disease involves more than weight loss — instead, it’s about improving the quality of life of patients through procedures, medications, and lifestyle modifications, they added.

Track New Developments

With ongoing changes in the field of metabolic and bariatric surgery, it’s helpful for clinicians to remain updated about new approaches across various disciplines linked to obesity management and treatment, said Christina Poa-Li, MD, a surgeon at Huntington Health Medical Center, affiliated with Cedars-Sinai Health System, in Pasadena, California, who was not involved in developing the updated practice statement.

“For example, the rapidly growing prescription of anti-obesity medications and their use in both preoperative and postoperative surgical patients drastically affect their nutrition,” she said. “Providers of various backgrounds and specialties will benefit from the most updated guidance on evaluating patient nutrition.”

Clinicians should consider expanding their patient population to include those with metabolic dysfunction–associated steatohepatitis or metabolic dysfunction–associated steatotic liver disease, Poa-Li said.

“These patient subpopulations may not have been considered for bariatric surgery or even referral to a bariatric surgeon for consultation previously,” she said. “It is important to increase awareness among clinicians of the potential benefits for metabolic and bariatric surgery for these patients.”

The report didn’t receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Patel and Poa-Li reported no relevant disclosures.

Carolyn Crist is a health and medical journalist who reports on the latest studies for Medscape, MDedge, and WebMD.