The Research Dietitians Role in a Weighed Diet

The Research Dietitians Role in a Weighed Diet Jamie Garry, MS, RD, LDN, CBDT MGH Clinical Research Center

Nutrient biomarkers may be diagnostic/ therapeutic Clinical Association Nutrient Biomarker Interventional Study In vivo Effects Diagnosis/ prognosis New nutritional therapy Proof concept Outcomes trial Effect on other biomarkers Change in nutrient level Effect on phenotype New Biology/Mechanism Walford - Nutrition New pharmacologic therapy 2

Clinical Association: � Published human studies have demonstrated that tryptophan is a competitive substrate for the organic cation transporter responsible for metformin elimination. � Questions: ◦ Does dietary tryptophan effect serum tryptophan ◦ Does serum tryptophan play a role in metformin response

Clinical Association: � Serum BCAA levels are correlated with insulin resistance � Questions: ◦ Does dietary intake of BCAA effect serum levels of circulating BCAA? ◦ Is there a correlation between serum BCAA and insulin resistance?

Nutrients effects of Serum Levels � Vitamin D – dietary intake directly effects blood levels � Cholesterol – dietary cholesterol not as directly related to serum cholesterol as once believed � Calcium - serum levels tightly regulated by body except in cases of disease

Tryptophan � Essential amino acids � Found in: meat, poultry, eggs, fish dairy, nuts, seeds, beans, grains, and bananas � Converts in body to: ◦ Serotonin ◦ Niacin � Tryptophan 48 hours) depletion occurs rapidly (~under ◦ Acute Tryptophan Depletion (ATD)

Branch Chain Amino Acids � Valine, Leucine and Isoleucine � Essential Amino Acids � Believed to improve athletic performance and muscle recovery ◦ Mixed research � Cannot be broken down by patient’s with Maple Syrup Urine Disease (MSUD)

Nutrient biomarkers may be diagnostic/ therapeutic Clinical Association Nutrient Biomarker Interventional Study In vivo Effects Diagnosis/ prognosis New nutritional therapy Proof concept Outcomes trial Effect on other biomarkers Change in nutrient level Effect on phenotype New Biology/Mechanism Walford - Nutrition New pharmacologic therapy 8

Interventional Studies � Proof of concept � Pilot studies on healthy individuals � Studies on patients with disease states � Phase 1 - 4 clinical trials ◦ Establish dosage ◦ Monitor for side effects ◦ Monitor effects of various populations

What is a Weighed diet? � Strictly controlled to diet developed to manipulate certain nutrients � Examples: Low sodium, TLC diet, renal diet

Creating a Weighed Diet � Considerations: ◦ ◦ ◦ ◦ Length of time Cost Study population Allergies/ intolerances Food safety Food procurement Metabolic Kitchen Amenities Staffing

Steps to Developing a Diet � Planning diet ◦ Pro. Nutra, NDSR � Procure Foods � Testing Recipes � Screen patients � Pack Out � Weight Back

Screening of Subjects � Assess typical intake � Dietary restrictions � Activity � Expected compliance � Access to storage

Calculating Needs � Estimating Current Consumption ◦ Food Records ◦ 24 hour or 48 hour recalls � Equations ◦ ◦ Mifflin St-Joer Harris Benedict Calories/Kg Activity Factors � Resting Energy Expenditure � Actual Weight versus Adjusted Weight

� Found Amino Acids in foods containing protein � Difficult to isolate in whole foods � Supplements � Pharmacy versus nutrition?

Supplements � MSUD Express – Low BCAA � Solvil – High BCAA � Tryptophan Supplements

Practical Implications � Increased pathways � Aid understanding of metabolic in medication development � Dietary recommendations � Evidence based practice

Next Steps Pilot study Disease specific Dosing/ Time New pharmalogical therapies

Thank You!