Can a Diet Focused on Glycemic Index Help Improve/Prevent Obesity?

CB Ebbeling, DS Ludwig. J Pediatr 2023; 255: 22-29. Open Access! Treatment for Childhood Obesity: Using a Biological Model to Inform Dietary Targets

This article describes the role of glycemic index and a carbohydrate-insulin model (CIM) in promoting obesity rather than the more conventional view of energy dense foods causing obesity.

  • In the CIM, “dysregulation of hormonal control over fuel partitioning in response to a high-glycemic load diet leads to excess fat deposition, as an antecedent to positive energy balance…. Consuming a high-glycemic index food causes a sharp increase in blood glucose followed by a rapid decline, whereas consuming a low-glycemic index food causes a more gradual increase and decrease with a lower peak. Decreasing dietary glycemic load involves lowering carbohydrate amount and selecting sources of carbohydrate with a low glycemic index. In general, low-glycemic load foods include nonstarchy vegetables, most temperate (vs tropical) whole fruits, and legumes; and high-glycemic load foods include potato products, processed grains, sweets, fruit juices, and sugary beverages.21“
  • “Fructose also increases fat deposition by upregulating enzymes of de novo lipogenesis via mechanisms independent of energy intake.22,23 Thus, the conventional understanding of obesity pathogenesis (overeating causes increasing adiposity) is opposed in the CIM (increasing adiposity causes overeating).”

“Dietary targets for which there is general consensus are:

  • Ample nonstarchy vegetables (eg, broccoli, lettuce), whole temperate fruits (eg, apple, orange, pear), and legumes
  • No sugar-sweetened beverages
  • Limited refined grains
  • Adequate protein

Additional dietary targets of particular relevance to the CIM which differ to some extent from conventional recommendations include:

  • Reduced amounts of starchy vegetables and total grains
  • Increased healthful fats (eg, nuts, seeds, avocado, olive oil)”

” When counseling, we recommend home-prepared protein (eg, poultry, fish) over preprepared items with breading (eg, chicken nuggets, fish sticks). We do not specifically recommend reduced-fat (1% or nonfat) dairy. Emerging observational data indicate that consuming whole vs reduced-fat milk is associated with lower adiposity in children,66…Regarding milk with added sugar and flavoring (eg, chocolate milk), prospective data indicate a direct association between consumption and adverse changes in body composition”

Three main goals with this diet approach:

  1. Eat balanced meals  – Follow a Plate Model
  2. Eat Paired Snacks When Hungry Between Meals
  3. Stop and Think Before You Drink Sugary Beverages – Drink Water Instead

My take: I have favored the Mediterranean diet as a general goal for patients concerned with healthy eating. This article challenges the conventional approach of targeting energy dense foods in favor of avoiding high glycemic carbohydrates.

This article is a good resource–more information available at these links:

The Peanut Story -Skin Patch Chapter

  • M Greenhawt et al. NEJM 2023; 388: 1755-1766. Phase 3 Trial of Epicutaneous Immunotherapy in Toddlers with Peanut Allergy
  • Editorial: A Togias. NEJM 2023; 388: 1814-1815. Good News for Toddlers with Peanut Allergy

Methods: This was a phase 3, multicenter, double-blind, randomized, placebo-controlled (EPITOPE) trial involving children 1 to 3 years of age with peanut allergy confirmed by a double-blind, placebo-controlled food challenge. Patients (n=362) were randomized a 2:1 ratio to receive epicutaneous immunotherapy delivered by means of a peanut patch (250 mcg) (intervention group) or to receive placebo administered daily for 12 months. The primary end point was a treatment response as measured by the eliciting dose of peanut protein at 12 months. 

Key findings:

  • The primary efficacy end point result was observed in 67.0% of children in the intervention group as compared with 33.5% of those in the placebo group
  • Treatment-related anaphylaxis occurred in 1.6% in the intervention group and none in the placebo group

Points from the editorial:

  • “The primary finding is that after receiving treatment with the peanut patch for a year, 67.0% of the toddlers in the intervention group could safely ingest the peanut-protein equivalent of approximately three to four peanuts or approximately one peanut, depending on how sensitive to peanut they were at baseline. In the placebo group, 33.5% of the children reached this end point…many practitioners have been using orally delivered foods for the same purpose for approximately a decade.”
  • “A trial of peanut oral immunotherapy that did not involve the use of the commercially available product was recently conducted among children 1 to 3 years of age (the Oral Immunotherapy for Induction of Tolerance and Desensitization in Peanut-Allergic Children Trial [IMPACT]).5…The data suggest that oral immunotherapy may have a stronger protective effect than the effect reported in the EPITOPE trial.” Able to tolerate ingestion of 10 peanuts: “In the EPITOPE trial, 37% of the children in the intervention group and 10% of those in the placebo group had this result, as compared with 71% and 2%, respectively, in the IMPACT trial.”
  • ” On the other hand, epicutaneous immunotherapy appears to have a better safety profile than oral immunotherapy…For example, allergic reactions that resulted in the administration of epinephrine occurred in 10% of the children in the intervention group in the EPITOPE trial and in 22% of those in the IMPACT trial. Also, eosinophilic esophagitis was seen in 3% of the children in the IMPACT trial who had received oral peanut immunotherapy.”

My take: Immunotherapy, oral or cutaneous, can result in some tolerance to peanuts in the majority of children. However, primary prevention of peanut allergy by timely introduction of peanuts in the diet could prevent the need for this intervention. Usually, introduction is at 4-6 months of age (though with specific precautions recommended in those with severe eczema and egg allergy).

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Sendero Esperanza -Hugh Norris to Wasson Peak Trails, Tucson

IV Versus Oral Iron in Children with Anemia –POPEYE Study

N Bevers et al. J Pediatr 2023; 256: 113-119. Open Access! Ferric Carboxymaltose Versus Ferrous Fumarate in Anemic Children with Inflammatory Bowel Disease: The POPEYE Randomized Controlled Clinical Trial

Methods:  Children aged 8-18 (n=64) with IBD and anemia (defined as hemoglobin [Hb] z-score < −2) were randomly assigned to a single IV dose of ferric carboxymaltose (15 mg/kg up to 750 mg) or 12 weeks of oral ferrous fumarate (9 mg/kg/day up to 600 mg in BID divided dosing). This study excluded patients with severe disease activity (eg. PUCAI >65, or PCDAI >30).

Key findings:

  • One month after the start of iron therapy, the  6-minute walking distance (6MWD) z-score of patients in the IV group had increased by 0.71 compared with −0.11 in the oral group (P = .01).
  • At 3- and 6-month follow-ups, no significant differences in 6MWD z-scores were observed.
  • Hb z-scores gradually increased in both groups and the rate of increase was not different between groups at 1, 3, and 6 months after initiation of iron therapy (overall P = .97).
  • The authors did not detect hypophosphatemia which has been described with ferric carboxymaltose

This “POPEYE” study prompted me to review how much iron is in spinach. Apparently, it is a little more than in red meat. However, red meat iron is “heme” and is better absorbed than “non-heme” iron found in spinach.

My take: In this study, more rapid improvement in 6MWD was noted in first month of treatment but there were no other significant advantages of IV iron in this group which predominantly had quiescent disease or mildly active disease; hemoglobin improvement was comparable in both groups.

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More Lego Art from Tucson Botanical Gardens

Airway Impedance to Objectively Assess Airway Mucosal Integrity

R Rosen et al. J Pediatr 2023; 256: 5-10. Airway Impedance: A Novel Diagnostic Tool to Predict Extraesophageal Airway Inflammation

Airway appearance is not a reliable marker for aerodigestive disorders. This study (n=73 completed full study) sought to use airway impedance to provide an objective measure of airway mucosal integrity.

Methods: The direct laryngoscopy was performed and videotaped for blinded scoring by 3 otolaryngologists and a specially-designed impedance catheter was placed onto the posterior larynx to obtain measurements; the impedance sensors were placed immediately below vocal cords. Following this, an endoscopy was performed and impedance measurements and biopsies were taken.

Key findings:

  • Patients taking proton pump inhibitors had significantly lower mean airway impedance values (706 ± 450 Ω) than patients not taking them (1069 ± 809 Ω, P = .06).
  • Patients who had evidence of aspiration on video fluoroscopic swallow studies had lower airway impedance (871 ± 615 Ω) than patients without aspiration (1247 ± 360 Ω, P = .008)

Discussion:

  • Low impedance values have been correlated with esophageal inflammation. For example, in patients with active eosinophilic esophagitis impedance values of <1000 Ω are typical compared to >2500-3000 Ω in those without inflammation.
  • This study suggests that low laryngeal impedance prior to EGD can provide an objective marker of laryngeal mucosal integrity. Values were lower in those with impaired swallowing/aspiration. The association with lower values in those taking PPIs may be due to ongoing GERD (acid or nonacid) and/or ongoing pepsin exposure.
  • It is noted that airway impedance values were, “on average, 3-fold lower than esophageal impedance values, highlighting the differences in these microenvironments.”
  • Limitations: No healthy controls

My take: Frequently, aerodigestive patients undergo extensive evaluations. This is a simple technique that could easily be added; it may be an objective marker of airway disorders “and may help reduce acid suppression use previously driven by these visual exams.”

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Satire, from The Onion

Fatty Liver Disease AASLD Practice Guidance 2023

ME Rinella et al. Hepatology 2023; 77: 1797-1835. Open Access! AASLD Practice Guidance on the clinical assessment and management of nonalcoholic fatty liver disease

This 38 page report has a ton of updated recommendations and useful advice –geared to adults with fatty liver disease. The last ~dozen pages are the 491 references.

Some of the useful points:

  • CVD and nonhepatic malignancies are the most common causes of mortality in patients with NAFLD without advanced fibrosis; death from liver disease predominates in patients with advanced fibrosis.
  • Initial lab evaluation in adults:
  • Statins are safe and recommended for CVD risk reduction in patients with NAFLD across the disease spectrum, including compensated cirrhosis.
  • Patients with NAFLD should be screened for the presence of T2DM. T2DM is the most impactful risk factor for the development of NAFLD, fibrosis progression, and HCC.108–111 Given the central pathogenic role that insulin resistance plays in the pathogenesis of both T2DM and NAFLD, it is not surprising that patients with T2DM have a higher prevalence of NAFLD (ranging from 30% to 75%)10,112,113 and a higher risk of developing NASH with fibrosis.93,114–117 
  • Other important comorbidities: dyslipidemia, obstructive sleep apnea, cardiovascular disease, and chronic kidney disease

Lifestyle factors that can be beneficial:

  • Table 6 lists potential medications though there are no FDA approved treatments for fatty liver disease. Bariatric surgery is also a beneficial treatment option “in patients who meet criteria for metabolic weight loss surgery, as it effectively resolves NAFLD or NASH in the majority of patients without cirrhosis and reduces mortality from CVD and malignancy.”
  • Potentially useful medications include Vitamin E, Pioglitazone, Liraglutide, Semaglutide, Tirzepatide and SGLT-2i. “Semaglutide can be considered for its approved indications (T2DM/obesity) in patients with NASH, as it confers a cardiovascular benefit and improves NASH. Pioglitazone improves NASH and can be considered for patients with NASH in the context of patients with T2DM . Available data on semaglutide, pioglitazone, and vitamin E do not demonstrate an antifibrotic benefit, and none has been carefully studied in patients with cirrhosis.”
  • Treatments NOT Recommended: “Metformin, ursodeoxycholic acid, dipeptidyl peptidase-4, statins, and silymarin are well studied in NASH and should not be used as a treatment for NASH as they do not offer a meaningful histological benefit.”

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Most Kids with Rumination Respond to Specialized Treatment

J Sabella et al. JPGN 2023; 76: 282-287. Multidisciplinary Tiered Care Is Effective for Children and Adolescents With Rumination Syndrome

The was a retrospective single-center study (n=171). The median length of treatment was 6.5 months for outpatient care, four days for intensive outpatient care and nine days for intensive inpatient care.

Key findings:

  • After treatment, 72% of OP, 95% of IOP, and 96% of IP patients reported that symptoms were better or fully resolved compared to baseline
  • In a subset of 16 children, At follow-up (median 5.3 months), 86% of IOP and 66% of IP patients had symptoms that remained better or resolved.
  • The authors found “an association between patient or family reluctance to accept the diagnosis of rumination syndrome and a lack of response to treatment. Prior studies have demonstrated the importance of commitment and belief in the process of treatment and/or fully commit to the behavioral treatment process as a barrier to care.”

In a commentary on this article from Pediatrics Nationwide, Dr. Peter Lu noted: “What was striking to me was how effective the intensive treatment programs are. Both of those groups included the most severe of patients, oftentimes, they’ll have a feeding tube or a central line for parenteral nutrition. Even in that selected, very severe refractory group, we had very good response rates to treatment…RS is a disorder that cannot be effectively treated by a GI doctor alone…Treatment of RS involves a GI doctor and a GI psychologist, and we oftentimes will involve one of our GI dieticians”

My take: This study shows that treatment can be very effective in treating rumination syndrome, especially if the patient/family is amenable to therapy.

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Also, good tips on managing rumination were given on a bowel sounds podcast: Desale Yacob & Ashley Kroon Van Diest – Rumination Syndrome (August 2021)

Linaclotide -Now FDA-Approved for Children

FDA 6/12/23: FDA approves first treatment for pediatric functional constipation

“FDA has approved Linzess (linaclotide) capsules to treat functional constipation in pediatric patients 6 to 17 years of age. Linzess is the first treatment for pediatric functional constipation. The recommended dosage in pediatric patients 6 to 17 years is 72 mcg orally once daily.”

“The efficacy of Linzess for the treatment of functional constipation in pediatric patients 6 to 17 years of age was established in a 12-week double-blind, placebo-controlled, randomized, multicenter clinical trial (Trial 7; NCT04026113) and supported by efficacy data from adequate and well-controlled trials in adults with chronic idiopathic constipation (constipation that persists and isn’t connected to an underlying illness).”

Safety:

  • Most common adverse effect was diarrhea
  • Avoid in patients with known or suspected mechanical gastrointestinal obstruction (bowel blockage)
  • “Linzess contains a boxed warning that the medication should not be taken by patients less than 2 years of age”
  • See full prescribing information for additional information on risks associated with Linzess.

My take: While this is good news to have the first FDA-approved treatment for pediatric functional constipation, it is worth remembering that the estimated cost for a monthly supply is between $514-$536 (in Atlanta pharmacies per GoodRx.com).

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Comparing Outcomes Between PEG Placement and Surgical GT Placement

K Tazi et al. JPGN Reports 4(2):p e316, May 2023. | DOI: 10.1097/PG9.0000000000000316. Open Access: Complications of Percutaneous and Surgical Gastrostomy Placements in Children: a Single-Centre Series.

In this retrospective single-center pediatric (n=124) study, the authors analyzed complications that occurred up to 1 year after placement. Key findings:

  • Fifty-nine patients (47.6%) underwent endoscopic placement, 59 (47.6%) surgical placement, and 6 (4.8%) laparoscopic-assisted percutaneous endoscopic gastrostomy. 
  • 29 (14.4%) major and 173 (85.6%) minor complications were reported
  • This study highlights at least 1 complication (regardless of severity) in 106 (85.5%) patients and reports a significantly lower complication rate in the PEG group (major and minor combined) compared to the surgical group (laparoscopy and laparotomy) (OR, 0.3; 95% CI, 0.07–0.9) (P = 0.001).
  • In the endoscopic group, patients with concomitant neurological disease had significantly more early complications (25.8 vs. 3.6%; OR, 9.1)
  • In the surgical group, patients with undernutrition had significantly more major complications (12.1% vs. 40%; OR, 4.7; 95% CI, 1.2–18; P = 0.01)

Discussion:

  • The authors note that although their results found fewer complications in the PEG group, other studies have reported lower complications in surgically-placed GTs. “Baker et al (4). report, like Sanderg et al (9)., an advantage of the laparoscopic technique compared to the endoscopy technique in terms of major complication (OR, 0.29; 95% CI, 0.17–0.51; P = 0.0001). Several other studies (9,20,21) show similar results.”
  • “Although a single prophylactic antibiotic therapy with cefazolin is systematically administered before each procedure, the rate of infectious complications remains high: 13 cases of abdominal wall abscess or cellulitis (6.4% of total complications) and 33 cases of minor infection (16.3% of total complications) requiring local treatment.”
  • The strengths of this study are an exhaustive collection of detailed data permitting a precise analysis of complications

My take: The majority of studies suggest that laparoscopic GT placement is safer, unlike this study. A more definitive answer would require a randomized prospective study with rigorously-collected data. Also, GT complications are common, ~85% in this study; thus, family education is important both before and after GT placement.

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Disclaimer: This blog, gutsandgrowth, assumes no responsibility for any use or operation of any method, product, instruction, concept or idea contained in the material herein or for any injury or damage to persons or property (whether products liability, negligence or otherwise) resulting from such use or operation. These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  Because of rapid advances in the medical sciences, the gutsandgrowth blog cautions that independent verification should be made of diagnosis and drug dosages. The reader is solely responsible for the conduct of any suggested test or procedure.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

Skinny Babies with Cleft Lips and/or Cleft Palates

CM McKinney et al. J Pediatr 2023; 255: 181-189. A Cross-Sectional Study of the Nutritional Status of Infants with Orofacial Clefts in the First 6 Months of Life

In this cross sectional study (2010-2022) the authors calculated the proportion of infants (n=883) underweight and wasting with z scores below −2 SDs monthly from birth to 6 months of age at a single tertiary care center. Key findings:

  • Compared with expected proportion of underweight infants (2.3%), a larger proportion of infants with orofacial clefts were underweight between birth and 1 month (10.6%), peaking between 2 and 3 months (27.1%), and remaining high between 5 and 6 months (16.3%). 
  • Compared with the expected proportion of infants with wasting (2.3%), a higher proportion of infants with orofacial clefts experienced wasting between birth and 1 month (7.3%), peaking between 2 and 3 months (12.8%), and remaining high between 5 and 6 months (5.3%).
  • Similar findings were observed for all cleft types and regardless of comorbidities.
  • “The mean prevalence of underweight in our sample exceeded that observed in children in African countries such as Tanzania and Uganda.”

My take: This study shows a high prevalence of underweight and wasting in infants with orofacial clefts.

Lego Art at Tucson Botanical Gardens:

More Proof That Transpyloric Feeds Protect the Lungs

B Srivatsa et al. J Pediatr 2023; 255: 175-180. Transpyloric Feeding is Associated With Improved Oxygenation Compared With Gastric Feeding Among Nonintubated Extremely Low Birth Weight Infants

As noted in a previous blog, transpyloric (TP) feedings are equivalent to a fundoplication in reducing reflux. As such, it is not surprising that it is used in premature infants to minimize reflux-associated respiratory problems including aspiration and potentially mitigate bronchopulmonary dysplasia.

In this retrospective study with 56 extremely low birth weight infants, the authors analyzed oxygen saturation (SpO2) and action of inspired oxygen (FiO2) data (measured at 1-minute intervals) for 96 hours before and after institution of TP feeds.

Key findings:

  • No significant differences were observed in any oxygenation measures during TP vs gastric feeding among 14 intubated infants.
  • Among 42 nonintubated patients, significant improvements were observed in the median SpO2/FiO2 ratios (P = .001), median titration index (P = .05), median number of hypoxemic episodes (P = .02), and median severity of hypoxemic episodes (P = .008) after TP tube placement.

Discussion:

  • The authors note that a prior study (J Perinat Med 2021; 49: 383-387) had shown improvement in SpO2/FiO2 ratios in intubated patients (n=33). This discrepancy between the two studies could be due to differences in patient population, ventilation technique (high frequency vs conventional) and higher level of power due to more intubated subjects in the prior study.
  • The exact mechanism of improvement in oxygenation is a matter of speculation. “Does TP feeding in nonventilated patients result n fewer or less severe GER events, leading to less pulmonary microaspiration or laryngospasm?…Does aerophagia, more common among nonintubated patients on positive pressure support, exacerbate GER events and is it ameliorated with TP feedings?” It is also possible that TP feedings result in improvement due to a reduction in esophageal reflux mediated bronchoconstriction.

My take: TP feedings have been very helpful in clinical practice, especially in infants with feeding difficulties, reflux, and respiratory issues. Most of these problems are transitory. This study provides granular data showing the significant improvements in oxygenation following the initiation of TP feedings among non-ventilated ELBW.

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