Energy Balance: The tight rope between too little and too much. Melanie Gillingham PhD, RD

Transcription

1 Energy Balance: The tight rope between too little and too much Melanie Gillingham PhD, RD

2 Too Little Energy: Symptoms of Fatty Acid Oxidation Disorders occur during negative energy balance Hypoketotic, hypoglycemia Muscle pain Rhabdomyolysis

3 Fatty Acid Oxidation When do we oxidize fat? Fasting Exercise What does Fatty Acid Oxidation produce? Energy (ATP) Acetyl-CoA for ketone synthesis

4 Too much energy: Calories consumed in excess of needs are stored as long-chain fatty acids Weight gain fatty acid storage

5 How do we know how much energy we need?

6 Components of energy expenditure: Basal Metabolic Rate (BMR): energy needed for basic function Thermal effect of food (TEF): energy needed to digest and absorb food Activity: energy needed to do daily activities, exercise, even fidget!

7 Basal Metabolic Rate (BMR) BMR related to muscle mass with age Varies by family

8 Basel Metabolic Rate Brain, liver heart, kidney comprise most metabolic active tissues at rest Muscle largest % of body weight

9 Activity Thermogenesis Activities of daily living or nonexercise activity thermogenesis (NEAT) Formal exercise program

10 Total Energy Expenditure

11 Total Energy Expenditure Important factors for energy needs: Muscle mass BMR Activity Are these things the same among people with a fatty acid oxidation disorder?

12 Measuring Muscle Mass Dual X-ray Absorptiometry (DEXA) Measured muscle mass & fat mass in 12 people with a FAO disorder and 12 controls.

13 Altered Body Composition Patients with a Longchain FAO disorder lower lean mass higher fat mass Energy expenditure function of lean mass slightly lower energy expenditure?

14 Measuring BMR Indirect Calorimetry measures O 2 consumed and CO 2 exhaled Measured BMR in 12 people with a FAO disorder and 12 controls.

15 Basal Metabolic Rate People with a Longchain FAO disorder had same resting energy expenditure per kg muscle mass

16 Measuring TEE Doubly labeled water Measured TEE with DLW in 12 people with a FAO disorder and 6 controls.

17 Altered Energy Expenditure People with a Longchain FAO disorder had approximately 15% lower total energy expenditure.

18 Body Temperature & Energy BMR increases with a fever

19 How much energy is just right? People with a long-chain fatty acid oxidation disorder have slightly lower muscle mass and total energy needs. Work with your metabolic dietitian to estimate the right energy for you or your child As always, be aware of changes in energy needs with illness or stress.

20 Increased Protein Intake Baseline Assessment: Body composition Energy Expenditure Exercise tolerance Standard Diet High Protein High Carbohydrate 4 month treatment period 4-month Assessment: Body composition Energy Expenditure Exercise tolerance High Protein protein carbohydrate LCFA MCT protein carbohydrate LCFA MCT

21 Increased Protein Intake

22 High Protein Diet Increased Muscle Change in Body Composition Change in Lean Mass by Age kg p = 0.02 * High Protein Standard Diet kg 4 High Protein Standard Diet lean mass fat mass Age (years) High protein increased lean mass. Lean mass loss in older subjects on standard diet.

23 Lower Liver Lipid Content 2 change in liver lipid (% of water peak) High Protein Diet Standard Diet High protein diet lowered liver lipid content

24 Triheptanoin Rhabdomyolysis occurs despite adequate energy? Inability to fully oxidize acetyl-coa? C7 provides source of propinoyl-coa to be converted to succinyl- CoA and improve acetyl- CoA oxidation

25 Phase 2 Trial of Triheptanoin Treatment Baseline Assessment: Body composition Energy Expenditure In vivo FAO Cardiac function Exercise tolerance Randomized Parallel Design MCT 20% energy 4 month treatment period 4-month Assessment: Body composition Energy Expenditure In vivo FAO Cardiac function Exercise tolerance Inclusion criteria: age 7-45 CPT2, VLCAD, LCHAD/TFP Ability to complete protocol Funded by FDA Office of Orphan Products Development R01FD03895