Metabolism and Pathophysiology of Bariatric Surgery

Nutrition, Procedures, Outcomes and Adverse Effects

Victor R Preedy, Rajkumar Rajendram, Colin R Martin, Victor R. Preedy, Colin R. Martin

• Publisher: Academic Press
• Year: 2016
• Print ISBN: 9780128040119
• eBook ISBN: 9780128040638
• Topic: Medicine
• Subtopic: Nutrition, Dietics & Bariatrics

Pathophysiology of Bariatric Surgery: Metabolism, Nutrition, Procedures, Outcomes and Adverse Effects uses a metabolic and nutritional theme to explain the complex interrelationships between obesity and metabolic profiles before and after bariatric surgery. The book is sectioned into seven distinct areas, Features of Obesity, Surgical Procedures, Nutritional Aspects, Metabolic Aspects, Diabetes, Insulin Resistance and Glucose Control, Cardiovascular and Physiological Effects, and Psychological and Behavioral Effects. Included is coverage on the various types of bariatric surgery, including Roux-en-Y gastric bypass, gastric banding, sleeve gastrectomy, biliopancreatic diversion, and jejunoileal bypass, as well as the variations upon these procedures. - Provides information on diet, nutrition, surgical procedures, outcomes, and side effects in relation to bariatric surgery in one comprehensive text - Contains a Dictionary of Terms, Key Facts, and Summary Points in each chapter - Includes access to a companion website with accompanying videos

Section V

Nutritional Aspects

Outline

• Chapter 44 Dietary Reference Values
• Chapter 45 Meal Disposal After Bariatric Surgery
• Chapter 46 Underreporting of Energy Intake and Bariatric Surgery
• Chapter 47 Control Eating Following Bariatric Surgery
• Chapter 48 Dietary Planning in Bariatric Surgery Postoperative
• Chapter 49 Protein Nutrition and Status and Bariatric Surgery
• Chapter 50 Micronutrient Deficiencies and Sleeve Gastrectomy for Weight Reduction
• Chapter 51 Thiamine (Vitamin B1) After Weight Loss Bariatric Surgery
• Chapter 52 Vitamin A and Roux-EN-Y Gastric Bypass
• Chapter 53 Iron and Bariatric Surgery

Chapter 44

Dietary Reference Values

M.Y. Price¹ and V.R. Preedy², ¹Royal Free London NHS Foundation Trust, London, United Kingdom, ²King’s College London, London, United Kingdom

Abstract

Patients who undergo bariatric surgery have nutritional treatment regimens that often entail supplementation of micronutrients as well as reductions in dietary energy intake. However, it is important to place these regimens in the context of normative requirements of micro- and macronutrients. Many of the multivitamin and multimineral supplements advocated for use are based on published dietary reference values (DRVs) for general populations in good health. In this chapter we contrast and compare subtleties between DRVs for adults in the United Kingdom, United States, and Japan. We present data for dietary energy, fats, proteins, carbohydrates, and a variety of micronutrients, including vitamins A, B1 (thiamine), B2 (riboflavin), B3 (niacin), B6, B12, C, D, E, and K, folate, pantothenic acid, biotin, calcium, magnesium, phosphorus, sodium, potassium, chloride, iron, zinc, copper, selenium, molybdenum, manganese, chromium, and iodine.

Keywords

Dietary reference intakes; dietary reference values; recommended dietary allowances; minerals; vitamins; multivitamins; multiminerals

List of Abbreviations

AIs adequate intakes

DRIs dietary reference intakes

DRVs dietary reference values

EAR estimated average requirement

LRNI lower reference nutrient intake

RDAs recommended dietary allowances

RNI reference nutrient intake

SACN scientific advisory committee on nutrition

SI safe intake

ULs tolerable upper intake levels

Introduction

Patients who undergo bariatric surgery have specific nutritional requirements before and after surgery [1,2]. These include reducing overall caloric intake before surgery as well as addressing any micronutrient imbalance. Some micronutrient deficiencies arise before surgical procedures as a consequence of obesity per se, and also as a consequence of the presurgical weight loss procedures themselves. For example, as many as 70% of subjects who are about to undergo bariatric surgery are at risk of vitamin D deficiency [1,3]. In one study, 63% of patients were deficient in folate and 98% deficient in vitamin D, though none were deficient in vitamin E prior to surgery [4]. As a consequence of the surgery itself, micro- and macronutrient deficiencies will also arise unless treated [5,6]. For example, fat malabsorption as a consequence of bariatric weight loss procedures will have implications for the status of fat-soluble vitamins A and D, necessitating supplementation in the long term [7,8]. Supplementation with multivitamin and mineral preparations are frequently advocated for use after bariatric surgery [9–13]. An understanding of nutrient supplementations in bariatric surgery is dependent upon an understanding of the normative requirements for the general population.

Micro- and Macronutrients

There are four levels at which dietary components should be considered:

• Level 1. The micro- and macronutrient compositions of foods.
• Level 2. The amount of ingested micro- and macronutrients.
• Level 3. The requirements of micro- and macronutrients.
• Level 4. The status or levels of micro- and macronutrients.

For these four levels of consideration, the amount of ingested nutrients in Level 2 will depend on the micro- and macronutrient compositions of foods and portion size (Level 1). While there are numerous methods for calculating dietary intakes, e.g., with the combined use of food diaries, questionnaires, and food composition tables [14,15], a fundamental question arises as to how much of a particular macronutrient an individual needs, which is the basis of Level 3. The status of micro- and macronutrients (Level 4) will depend on various factors such as genetic variability, the specific forms of the nutrients (e.g., heme and nonheme iron), competitive interactions, and so on (reviewed in Ref. [16]).

In the United Kingdom, the requirements of individuals and populations are termed the dietary reference values (DRVs) [16]. However in many countries, the terms DRVs, recommended values, recommended daily intakes (RDIs), or recommended daily allowance are used interchangeably, even though they mean the same thing, namely imparting advice on what people should consume in order to achieve optimal health and prevent disease. Some systems have also been updated with concomitant name changes. For example, in the United Kingdom the DRVs replaced the UK RDIs of 1979, which in turn replaced the UK recommended daily amounts (RDAs) of 1969 [16]. There may also be some confusion in that terms used in the United Kingdom (DRVs) are not used in the United States. Furthermore, terms previously used in the United Kingdom (RDAs) are presently used in the United States. To address this it is beneficial to document three systems of guidance in detail and define the terms that are often used (Table 44.1).

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Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of Contributors
• Foreword
• Preface
• Section I: Features of Obesity and Strategies for Weight Loss
• Section II: Surgical and Postsurgical Procedures
• Section III: Safety and Outcomes
• Section IV: Metabolism, Endocrinology and Organ Systems
• Section V: Nutritional Aspects
• Section VI: Cardiovascular, Body Composition, and Physiological Aspects
• Section VII: Psychological and Behavioral Aspects
• Section VIII: Resources
• Index